Tag Archives: Denver weather history

November 15 to November 21: This week in Denver weather history

This Week in Denver Weather History

Any week in Denver weather history is filled with numerous notable weather events and this week is no different.  We have everything from major snowstorms to damaging winds and much more.  However, one item is particularly notable and historic.  It was on the 20th of November in 1871 that the first, official weather observation took place in Denver.  Henry Fenton, Observer Sergeant of the United States Army Signal Service, made the report at 5:43 am.  The office was located on the 2nd floor of a building at the corner of Larimer and G Streets, now 16th Street.  Scroll down to see what the report said.

From the National Weather Service:

From the 12th to the 15th:

In 1909…light snowfall totaled 6.7 inches in downtown Denver over the 4 days.  This was the first measurable snowfall of the season.  Northeast winds were sustained to 15 mph on the 12th.

From the 14th to the 15th:

In 1917…overnight rainfall was 0.03 inch.  This was the only measurable precipitation of the month…making it the 5th driest November on record.

In 1985…3 to 6 inches of snow fell across metro Denver. Snowfall totaled 3.8 inches at Stapleton International Airport where northeast winds gusted to only 13 mph.

In 2005…a winter storm that brought heavy snow to the mountains also spread heavy snow into the foothills to the west of Denver.  Snowfall totals included:  14 inches at Aspen Springs…13 inches near Pinecliffe…and 12 inches near Nederland.  Interstate 70 along with U.S. Highway 40 had to be closed near Idaho Springs due to snow…poor visibility in blowing snow…numerous accidents…and an increased avalanche danger.  High winds were recorded in the foothills on the 14th.  Winds gusted to 89 mph at Georgetown and to 91 mph on Sugarloaf Mountain west of Boulder.  Strong microburst winds associated with a dissipating rain shower gusted to 61 mph at Denver International Airport on the 14th.

In 2009…a storm system produced heavy snow over parts of Front Range foothills…urban corridor and Palmer Divide. Storms totals in the Front Range foothills included: 13.5 inches…6 miles southwest of Evergreen and near Genesee; 13 inches…3 miles northwest of Idledale; 12 inches…3 miles north of Conifer and near Kittredge; 11 inches…12 miles southwest of Boulder and 3 miles southeast of Indian Hills and at Strontia Springs dam; 10 inches near Bailey…Bergen Park and Crow Hill; 9.5 inches near Blackhawk and 4 miles east-northeast of Nederland. Across the urban corridor and Palmer Divide storm totals included: 12 inches at Highlands Ranch…11 inches…5 miles south-southwest of Arapahoe Park and Louviers; 10 inches…4 miles south of Denver; 9 inches near Englewood…Lakewood… And Wheat Ridge; 8 inches at Aurora and 3 miles south-southwest of Castle Pines; 7.5 inches…3 miles southeast of Denver; with 7 inches 2 miles north-northeast of Commerce City. At Denver International Airport…7.3 inches of snowfall was observed.

From the 14th to the 18th:

In 1964…the first measurable snowfall of the season totaled 6.0 inches at Stapleton International Airport where northeast winds gusted to 32 mph on the 14th. Most of the snow…4.2 inches…fell on the 14th.  This was the only measurable snow of the month.

On the 15th:

In 1902…4.0 inches of snow fell over downtown Denver. This was the only measurable snow of the month. Northeast winds were sustained to 18 mph with gusts to 20 mph.

In 1906…strong winds howled and roared across Boulder… Causing several thousand dollars in damage.  The strong winds caused one fatality and minor injuries to others. West winds were sustained to 46 mph in downtown Denver where the strong Chinook winds warmed the temperature to a high of 74 degrees.

In 1944…the low temperature dipped to 32 degrees.  This is the latest date of the first freeze in Denver.

In 1949…a trace of rain fell.  Another trace of rain on the 11th was the only precipitation of the month…making the month one of the driest Novembers on record and the least snowiest with no snow.  This was the first November since 1882 without snow.

In 1960…strong winds caused 2 thousand dollars damage to a new school building in Boulder where wind gusts were estimated to 70 mph.  Wind gusts to 40 mph were recorded in downtown Denver.  Damage occurred to utility lines…signs… And trees.  Northwest winds gusted to 44 mph at Stapleton Airport.

In 1986…strong Chinook winds howled over the Front Range foothills.  The highest wind gust…81 mph…was recorded at Table Mesa in Boulder.  West winds gusted to 31 mph at Stapleton International Airport.

In 1987…the first measurable snow of the season was also a major snowstorm.  The snow combined with strong winds to close I-70 east of Denver and I-25 to Colorado Springs. Snow accumulations ranged from 6 to 9 inches across metro Denver with 10 to 20 inches in the foothills.  At Stapleton International Airport…6.1 inches of snow fell and north winds gusted to 47 mph reducing the visibility to as low as 1/8 mile in heavy snow.  Strong north winds at 20 to 30 mph with frequent gusts to 40 mph and temperatures hovering around 30 degrees plunged wind chill temperatures to 5 below zero.

In 1988…the season’s first snow storm hit metro Denver. The storm dumped 2 to 5 inches of snow…which caused numerous traffic snarls and accidents.  North wind gusts to 43 mph caused some blowing snow.  Snowfall totaled 2.5 inches at Stapleton International Airport.  This was the latest first snow of the season.  No traces of snow had occurred earlier in the season.

In 2010…the combination of light snow…wind… Black ice and careless driving resulted in a 34-vehicle crash along Interstate 25 north of Monument. Five tractor-trailers were involved in the pileup. Although there were no fatalities… 18 people were seriously injured and taken to nearby hospitals. The northbound lanes of I-25 were closed for several hours…snarling the traffic between Denver and Colorado Springs.

From the 15th to the 16th:

In 1894…winds behind an apparent strong cold front were sustained to 60 mph with gusts to 75 mph on the 15th. Snowfall totaled 2.6 inches in the city.  Temperatures plunged from a high of 72 degrees on the 15th to a low of only 5 degrees on the 16th.  The high temperature on the 16th was 24 degrees…which occurred shortly after midnight.

In 1996…around a foot of new snow fell in the foothills west of Denver with 3 to 6 inches at lower elevations across metro Denver.  Some of the snowfall totals included:  15 inches at Georgetown…12 inches at Idaho Springs…10 inches at Chief Hosa…and 9 inches in Coal Creek Canyon.  Snowfall totaled 2.9 inches at the site of the former Stapleton International Airport.  Northeast winds gusted to 23 mph at Denver International Airport on the 16th.

From the 15th to the 17th:

In 1991…a strong winter storm dumped heavy snow over metro Denver.  Snowfall amounts totaled 15 inches at Castle Rock and conifer…14 inches at Morrison and Parker…12 inches in southeast Aurora…and 11.6 inches at Stapleton International Airport.  Winds were light with the storm.

On the 16th: Continue reading November 15 to November 21: This week in Denver weather history

November 8 to November 14: This week in Denver weather history

This Week in Denver Weather History

Wind is always a factor on the plains and the fall usually brings a great deal of it, especially in November.  Our look back at this week in Denver weather history shows that event and snow are quite common this time of year.

From the National Weather Service:

From the 7th to the 8th:

In 1969…wind gusts to 48 mph in downtown Boulder caused minor damage.

On the 8th:

In 1896…southwest Chinook winds sustained to 42 mph with gusts as high as 46 mph warmed the temperature to a high of 53 degrees.

In 1977 near-blizzard conditions in blowing snow caused the closure of I-70 to the west of Denver in clear creek canyon and east of Denver to Limon.  Northeast wind gusts to 46 mph were recorded at Stapleton International Airport where snowfall totaled only 1.1 inches.

In 1984…a rare November thunderstorm produced west winds gusting to 31 mph…but only 0.04 inch of rain at Stapleton International Airport.

In 1996…high winds gusting from 80 to 100 mph were recorded at Wondervu in the foothills southwest of Boulder.  West northwest winds gusted to 32 mph at Denver International Airport.

In 2006…the temperature in Denver climbed to a high of 80 degrees.  This was the first time the temperature had ever exceeded the 70’s in November since records began in 1872. This new all-time record maximum temperature for the month of November was also a new daily record and the highest temperature ever recorded so late in the season.

From the 8th to the 9th:

In 1897…west winds were sustained to 45 mph with gusts as high as 50 mph in the city.

In 1919…post-frontal heavy snowfall totaled 8.4 inches over downtown Denver.  Most of the snow…6.6 inches…fell on the 9th.  North winds were sustained to 26 mph with gusts to 30 mph on the 8th.

In 1950…a major winter storm dumped 10.4 inches of snow at Stapleton Airport with the most snow…7.8 inches…falling on the 8th.  East winds gusted to 31 mph at Stapleton Airport on the 8th.  Snowfall totaled 8.2 inches in downtown Denver.

In 1958…strong winds caused some damage in Boulder.  West- northwest winds gusted to 40 mph at Stapleton Airport on the 8th.

In 1975…heavy snowfall hit metro Denver.  Snowfall at Stapleton International Airport totaled 8.0 inches and east winds gusted to 21 mph.  Power outages caused by the storm affected over 10 thousand people in metro Denver.  In the foothills west of Denver…10 to 15 inches of snow fell. The storm produced the greatest 24-hour precipitation…1.29 inches…ever recorded during the month of November in the city.

In 1983…metro Denver received 4 to 8 inches of snow with the heaviest amounts near the foothills.  It was the first measurable snow of the season in Denver.  Only 1.8 inches of snow fell at Stapleton International Airport where north winds gusted to 20 mph.

In 1989…strong winds hit the Front Range.  On the 9th…the wooden frame of a house under construction in Boulder was blown down.  The previous evening a power outage blackened Nederland.  Wind gusts to 95 mph were recorded 4 miles south of Rollinsville with 97 mph on fritz peak near that town.  At Stapleton International Airport…northwest winds gusted to 45 mph on the 8th and to 38 mph on the 9th.

In 1998…another upslope snow event developed in the Front Range foothills.  The heaviest snowfall occurred in west central Jefferson County where 14 inches were measured 8 miles west of conifer.  Other snowfall totals included: 10 inches at evergreen and 9 miles northwest of Bergen Park; 9 inches at Genesee…Nederland…and near the Chief Hosa exit on I-70; and 8 inches in Coal Creek Canyon.  On the 9th…snowfall was 2.6 inches at the site of the former Stapleton International Airport.  North-northeast winds gusted to 30 mph at Denver International Airport on the 9th.

From the 8th to the 10th:

In 1985…Indian summer came to an abrupt end when a winter storm dumped 10 to 18 inches of snow in the Front Range foothills and 6 to 10 inches across metro Denver…snarling traffic and causing flight delays of up to 3 hours at Stapleton International Airport.  The temperature plunged from a high of 66 degrees on the 8th to a low of only 13 degrees on the 9th…after the passage of a vigorous cold front with northeast winds gusting to 32 mph.  The temperature climbed to only 19 degrees on the 10th…setting a record low maximum for the date.  Snowfall totaled 7.3 inches at Stapleton International Airport with most of the snow…7.1 inches…falling on the 9th.

On the 9th:

In 1939…a trace of snow fell over downtown Denver.  This snow…along with a trace of snow on the 2nd…was the only snow of the month…ranking it…along with other months…the second least snowiest November on record.  Precipitation of 0.01 inch was the only precipitation of the month…making this the second driest November on record.

In 1944…the first killing frost of the season occurred in the city when the low temperature dipped to 35 degrees. This is the latest date for a killing frost ever recorded in Denver.

In 1946…heavy snowfall totaled 7.7 inches over downtown Denver.  This was the second heavy snowfall in less than a week.  Northwest winds were sustained to 26 mph.

In 1995…strong downslope winds gusted between 50 and 57 mph at Erie and Boulder.  West wind gusts to 44 mph were recorded at Denver International Airport.

In 2014…a record high min of 45 degrees… Broke the previous record of 43 degrees set in 1934…and preceded several days of record cold temperatures from the 11th through the 13th.

On the 10th:

In 1897…west Chinook winds sustained to 51 mph with gusts to 60 mph warmed the temperature to a high of 64 degrees.

In 1915…southwest winds were sustained to 41 mph with gusts as high as 44 mph.

In 1955…strong winds raked the eastern foothills.  A wind gust to 80 mph was recorded atop Rocky Flats south of Boulder where some damage occurred.

In 1995…snowfall totaled 6 to 9 inches in the foothills west of Denver…while only 2.2 inches of snow fell at the site of the former Stapleton International Airport. North-northeast winds gusted to 31 mph at Denver International Airport.

In 1998…strong Bora winds gusting from 70 to 92 mph coupled with blowing snow created whiteout and slick black ice conditions at the base of the foothills west of Denver. State Highway 93 between Golden and Boulder and C-470… Near the Morrison interchange were closed for several hours due to multiple car accidents.  Dozens of motorists were stranded until weather conditions improved.  A small motor home was a total loss when it caught fire after being blown on its side by strong crosswinds.  A man was injured when he was blown off a vehicle while attempting to rescue the occupants.  Wind gusts included:  92 mph atop Blue Mountain near Coal Creek Canyon…83 mph atop fritz peak near Rollinsville…and 77 mph at Jefferson County airport near Broomfield.  West winds gusted to 36 mph at Denver International Airport.

In 2000…freezing drizzle was widespread across northeastern Colorado with the heaviest amounts near the foothills in the evening.  The freezing drizzle made many highways icy and slick…which contributed to a number of traffic accidents.  Some highways across metro Denver were closed at times…including portions of State Highway 119 between Boulder and Longmont and U.S. 36 between Westminster and Boulder.  State Highway 93 between Boulder and Golden atop Rocky Flats became nearly impassable due to a coating of ice by late evening.

From the 10th to the 11th:

In 1911…a strong cold front produced snow and a cold wave. The temperature dropped 68 degrees from a high of 66 degrees at 12:40 pm on the 10th to a low of 2 degrees below zero at 7:15 am on the 11th.  The low temperature of 23 degrees at midnight on the 10th was also the high temperature on the 11th.  Northeast winds were sustained to 42 mph with gusts to 51 mph.  Snowfall was only 2.5 inches.

In 1982…up to 4 inches of snow fell over the higher terrain between Denver and Colorado springs.  Winds gusted to 50 mph along the foothills.  Rainfall totaled 0.27 inch with only 0.1 inch of snow on the 11th at Stapleton International Airport where north winds gusted to 39 mph. Dense fog with visibilities as low as zero persisted all day on the 10th.

Continue reading November 8 to November 14: This week in Denver weather history

November 1 to November 7: This week in Denver weather history

This Week in Denver Weather History

As we enter Denver’s second snowiest month, we of course see plenty of events involving that dominant weather condition.  Sadly we also see two occasions when the winter-like weather turned deadly.

From the National Weather Service:

From the 29th to the 1st:

In 1972…heavy snowfall totaled 15.5 inches at Stapleton International Airport.  However…the heaviest snow occurred on Halloween night when 7 inches fell on trick-or-treaters during a short 3-hour period.  I-25 was closed south of Denver.  North winds gusting to 29 mph caused some blowing snow on the 1st.  The snow started late on the 29th and ended during the mid afternoon on the 1st.  The greatest snow depth on the ground at Stapleton International Airport was 13 inches on the 1st.

From the 31st to the 1st:

In 1951…6.4 inches of snowfall were measured at Stapleton Airport.

In 1989…a Halloween storm dropped 3 to 6 inches of snow on metro Denver with the adjacent foothills receiving 5 to 10 inches.  Snowfall totaled 4.5 inches at Stapleton International Airport…where north winds gusted to 31 mph on the 31st.  Most of the snow fell on the evening of the 31st…but the storm left icy streets throughout metro Denver on the morning of the 1st…making it a “spooky” commute for many motorists.

In 2004…heavy snow fell in and near the foothills of Jefferson and Douglas counties.  Storm total snowfall included:  14.5 inches in Aspen Park…10 inches at Roxborough State Park and near Sedalia…8 inches near Bergen Park…and 7 inches in Highlands Ranch.  Snowfall totaled only 3.2 inches in the Denver Stapleton area.  Post-frontal northeast winds gusted to 41 mph at Denver International Airport.

On the 1st:

In 1896…northwest Chinook winds sustained to 40 mph with gusts to 46 mph warmed the temperature to a high of 60 degrees in the city.

In 1973…wind gusts to 92 mph were recorded in Boulder. West winds gusted to 41 mph at Stapleton International Airport where the Chinook winds warmed the temperature to a high of 70 degrees.

In 1989…a 39-year-old Lakewood man in a motorized wheelchair was found dead of exposure early in the morning after an overnight snowfall dumped 3 to 6 inches of snow across metro Denver.

From the 1st to the 2nd:

In 1892…snowfall totaled 5.0 inches in downtown Denver. This was the only snow of the month.

In 1956…heavy snowfall totaled 7.0 inches at Stapleton Airport.  The storm was accompanied by much blowing and drifting snow.  North winds gusted to 47 mph.

In 1991…the storm system which hit the Front Range at the end of October finished the job during the start of November.  Six inches of new snow were recorded at both Rollinsville and Morrison…while 2.9 inches of snow fell at Stapleton International Airport where northeast winds gusted to 17 mph.  The temperature climbed to a high of only 19 degrees on the 2nd…setting a record low maximum for the date.

In 1995…a winter storm dropped 5 to 8 inches of snow in the Front Range foothills.  The exception was at Golden gate canyon where a foot of new snow was measured.  Icy roads…fog…and blowing snow along I-70 in the foothills west of Denver caused dozens of accidents.  One man was killed when he lost control of his vehicle and was ejected when his truck hit a median and rolled over.  At least 20 other accidents involved minor injuries.  Only 1.0 inch of snow fell at the site of the former Stapleton International Airport where some freezing rain also fell.

On the 2nd:

In 1939…a trace of snow fell over downtown Denver.  This snow…along with a trace of snow on the 9th…was the only snow of the month…ranking it…along with other months…the second least snowiest November on record.

In 1967…post-cold frontal heavy snowfall totaled 6.2 inches at Stapleton International Airport where north winds gusted to 29 mph…briefly reducing the visibility to 1/8 mile.

In 1992…the first major snowfall of the season dumped 4.6 inches of snow at Stapleton International Airport where north winds gusted to 26 mph.  Heavier amounts of snow fell in and near the foothills with 8 inches at Conifer… Empire…and bailey…6 inches at Rollinsville and Golden Gate Canyon…and 4 inches at Morrison and Wheat Ridge.

In 2011…a storm system brought another around of moderate to heavy snow to the region. Areas in and near the Front Range foothills and palmer divide were hit the hardest. Gusty winds also produced blizzard conditions at times along the Palmer Divide. In addition…the snow and blowing snow forced several school closures in Douglas and Weld counties. Snow drifts…from 1 to 3 feet deep were reported in the northern portion of Douglas and Elbert counties. Storm totals included: 14 inches…4 miles south of Boulder and 12.5 miles northwest of Golden…13 inches… 5 miles east-southeast of Aspen Springs; 12 inches near Allenspark and Parker; 11 inches…6 miles southwest of Castle Rock…Genesee… 9 miles north-northeast of Elizabeth…10 inches… 10 miles south-southeast of Buckley AFB. At the National Weather Service in Boulder… 7.9 inches of snow was recorded…with 4.5 inches observed at Denver International Airport.

From the 2nd to the 3rd:

In 1974…heavy snowfall totaled 6.1 inches at Stapleton International Airport where north winds gusted to 23 mph on the 3rd.  Most of the snow fell on the 3rd.  Maximum snow depth on the ground was 5 inches.

In 1990…a winter storm dumped 3 to 8 inches of heavy wet snow across metro Denver.  In the foothills snow amounts ranged from 4 to 10 inches.  Slushy snow and ice-covered roads snarled traffic.  The snow…ice…and poor visibilities were blamed for numerous traffic accidents.  Low clouds… Fog…and snow delayed air traffic at Stapleton International Airport for at least 90 minutes on the afternoon of the 2nd. Snowfall totaled 5.4 inches at Stapleton International Airport where north winds gusted to 21 mph.

From the 2nd to the 5th:

In 1946…a major snow storm dumped 30.4 inches of heavy snowfall downtown and 31.0 inches at Stapleton Airport. The winter storm closed schools and disrupted all forms of transportation in the city.  The greatest depth of snow on the ground was 28 inches at the airport.  The duration of the snowfall…from 4:22 am on the 2nd to 3:08 am on the 5th… A total of 70 hours and 46 minutes…is the second longest period of continuous precipitation on record and the second heaviest snowfall of record at the time in Denver.  The 17.7 inches of snowfall on the 2nd and 3rd was the greatest 24- hour snowfall ever recorded during the month of November. Buses and street cars had a difficult time…and many cars were abandoned along roadsides and streets for several days. Secondary roads in rural areas were blocked for 2 to 3 weeks.  Several buildings in the city collapsed or were damaged from the weight of the heavy snow.  Football games were canceled.  Livestock losses were high over eastern Colorado.  The precipitation from this storm alone exceeded the greatest amount ever recorded in Denver during the entire month of November previously.  The precipitation recorded downtown was 2.03 inches…and the previous record for the entire month of November was 1.95 inches in 1922. North winds were sustained to 26 mph on the 2nd.

Continue reading November 1 to November 7: This week in Denver weather history

October 25 to October 31: This week in Denver weather history

This Week in Denver Weather History

Halloween week is historically pretty eventful when it comes to weather.  Wind is always a factor this time of year as gusty Chinook winds can come flying down the mountains and foothills and cause a great deal of damage.  Snow of course also becomes more frequent as we get closer to our second snowiest month (November).

From the National Weather Service:

From the 24th to the 25th:

In 1921…rainfall totaled 0.35 inch overnight behind an apparent cold front.  North winds were sustained to 40 mph with gusts to 46 mph on the 25th.  Temperatures plunged from a high of 73 degrees on the 24th to a low of 39 degrees on the 25th.

In 1923…rain overnight changed to snow during the morning. The heavy snowfall accumulated to 12.0 inches before ending on the morning of the 25th.  Post-frontal north winds were sustained to 22 mph with gusts to 23 mph on the 24th.

In 1997…one of the worst and deadliest blizzards of the decade developed over eastern Colorado as deep east to northeast flow associated with a vigorous upper level low pressure system over the four corners…combined with a strong arctic air mass over the central great plains. Snowfall totals across metro Denver ranged from 14 to 31 inches.  The heaviest snowfall occurred in the foothills west and southwest of Denver where 2 to 4 feet of snow were measured.  Sustained winds to 40 mph with gusts as high as 60 mph produced zero visibilities and extremely cold wind chill temperatures from 25 below to 40 below zero.  Winds whipped the snow into drifts 4 to 10 feet deep.  Several major and interstate highways were closed as travel became impossible.  Red cross shelters were set up for hundreds of travelers who became stranded when they had to abandon their vehicles.  Four people died in northeastern Colorado as a result of the blizzard.  None of the deaths were in metro Denver.  At Denver International Airport…4 thousand travelers were stranded when the airport was forced to shut down.  At least 120 cars were abandoned along Pena Blvd….the only arterial leading into and out of dia.  The blizzard cost air carriers at least 20 million dollars.  Thousands of cattle died in the storm over northeastern Colorado…resulting in losses totaling 1.5 million dollars.  Some of the more impressive snowfall totals included:  51 inches at Coal Creek Canyon; 48 inches at silver spruce ranch…near ward; 42 inches at Intercanyon…in the foothills southwest of Denver; 37 inches at Sedalia; 35 inches at aspen springs and Conifer in the foothills west of Denver; 31 inches at Eldorado Springs… Southeast Aurora…and Englewood; and 30 inches on Table Mesa in Boulder.  Snowfall totaled 21.9 inches at the site of the former Stapleton International Airport…setting a new 24-hour snowfall record of 19.1 inches for the month. Snowfall totaled only 14 inches at Denver International Airport where north winds gusted to 39 mph on the 24th. High temperature of only 21 degrees on the 25th equaled the record low maximum for the date first set in 1873. Low temperature of only 3 degrees on the 26th set a new record minimum for the date.

On the 25th:

In 1925…a vigorous cold front produced north winds sustained to 42 mph with gusts to 52 mph.  Post-frontal snowfall was only 0.4 inch during the late afternoon and early evening.

In 1959…northwest winds gusted to 55 mph at Stapleton Airport.

In 1997…the high temperature warmed to only 21 degrees… The record low maximum for the month.  The same temperature also occurred on October 30…1991.

From the 25th to the 26th:

In 1996…4 to 6 inches of snow fell in the foothills west of Denver.  Only 1.5 inches of snowfall were measured at the site of the former Stapleton International Airport on the 26th.  This was the only measurable snow of the month at the site.  The snowfall produced icy and snowpacked highways…which resulted in a 50-to 60-car pileup on I-25 south of metro Denver.  West winds gusted to 33 mph at Denver International Airport.

In 2006…a winter storm brought heavy snowfall to metro Denver and the eastern foothills.  Total snowfall ranged from 12 to 22 inches over the higher terrain and 6 to 12 inches across metro Denver.  Northerly winds at sustained speeds of 20 to 30 mph with gusts as high as 47 mph at Denver International Airport whipped the snow into drifts 3 to 4 feet deep.  Many tree limbs snapped under the weight of the heavy…wet snow which also downed power lines…  Leaving thousands of residents without power.  Storm total snowfall included:  25 inches near aspen springs…Conifer…  And Evergreen; 23.5 inches near Rollinsville; 23 inches in Idaho Springs; 22.5 inches near Blackhawk; 21.5 inches near bailey; 19 inches near Bergen Park; 18 inches near Aspen Springs…Genesee… And Jamestown; 17 inches southwest of Boulder; 16 inches in Evergreen; and 15 inches near Georgetown and Perry Park.  Snowfall totaled 5.3 inches in the Denver Stapleton area.  At Denver International Airport…rain…including a thunderstorm… Changed to snow on the evening of the 25th after a high temperature of 70 degrees.

In 2010…a storm system brought heavy snow to the mountains west of Denver.  Storm totals included: 24 inches at the Eisenhower Tunnel…18 inches at Loveland Ski Area; with 16 inches at Arapahoe Basin.

From the 25th to the 27th:

In 1897…a major storm dumped 13.5 inches of snowfall over downtown Denver.  Rain changed to snow during the evening of the 25th and continued through mid-morning of the 27th. Most of the snow…12.0 inches… Fell on the 26th when north winds were sustained to 36 mph and gusts were as high as 46 mph.  Temperatures during the storm were in the 20`s and lower 30`s.  Precipitation (rain and melted snow) totaled 1.21 inches.

On the 26th:

In 1995…winds gusting from 100 to near 110 mph pounded the foothills northwest of Denver.  At Nederland winds gusted to 100 mph and to 70 mph in Coal Creek Canyon.  Atop Squaw Mountain west of Denver wind gusts to 108 mph were recorded.  The strong winds downed some trees and caused power outages.  West-northwest winds gusted to 47 mph at Denver International Airport.

In 2010…very strong winds during the day knocked down power lines in parts of Boulder.  The downed electrical lines sparked a small brush fire near Columbine Elementary School.  Strong wind gusts also damaged the tennis bubble at the Millennium Harvest House. In Northglenn, a tree was knocked down and caused minor damage to a mini-van parked nearby.  Peak wind gusts included: 70 mph at Berthoud…67 mph at Rocky Mountain Metropolitan airport in Broomfield… 63 mph at the Rocky Flats National Wind Technology Center and 59 mph at the NCAR Mesa Laboratory…3 miles southwest of Boulder.  West winds gusted to 43 mph at Denver International Airport.

In 2011…a powerful early season storm brought heavy snow to the Front Range and adjacent plains. The heavy…wet snow caused extensive downed large branches and in some cases…entire trees. Massive power outages occurred from Fort Collins and Greeley south to Denver and the surrounding metro area. Most of the trees still had their leaves…which helped to catch snow and down trees under the weight of the moisture laden snow. Nearly two hundred thousand utility customers along the Front Range were without heat and electricity for several hours. The Red Cross opened four temporary shelters overnight until the power could be restored. The outages also forced the closure of the Boulder criminal justice center the following day. The fallen trees and branches also caused extensive property damage to roofs and automobiles. In the Front Range mountains and foothills…storm totals included 19.8 inches…3 miles west of Jamestown; 18 inches…5 miles west of Copper; 13 inches… 3 miles north of Blackhawk and 3 miles south of Evergreen…4 miles east-northeast of Nederland and Lake Eldora; 12 inches at Berthoud SNOTEL. Across the urban corridor storm totals included: 11.5 inches in Boulder; 9.5 inches at the National Weather Service in Boulder; 9 inches…1 mile southwest of Westminster; 8.5 inches in Broomfield… Denver International Airport…Frederick and Louisville; 8 inches in Aurora…7 inches in Watkins; with 6 inches in Arvada.

From the 26th to the 27th:

In 1971…strong winds raked Boulder.  At the National Bureau of Standards wind gusts to 62 mph were recorded…while in downtown Boulder winds peaked to 48 mph.  At Stapleton International Airport…northwest winds gusted to 38 mph on the 26th and north winds gusted to 36 mph on the 27th.

In 1976…the first measurable snow of the season turned into a major storm.  Traffic was halted for several hours on highways to the west of Denver where 8 to 12 inches of snow fell in the foothills.  Snowfall totaled 7.2 inches at Stapleton International Airport where north winds gusted to 30 mph.  Most of the snow…6.3 inches… Fell all day on the 26th.  The greatest snow depth on the ground was 5 inches on the morning of the 27th.

On the 27th:

In 1980…the first snowfall of the season totaled only 1.5 inches with 0.10 inch of moisture at Stapleton International Airport where the maximum snow depth on the ground was only 1 inch due to melting.  This was the only measurable precipitation of the month…making it the driest October since 1962 when only 0.03 inch of precipitation was measured.

In 1994…wind gusts to 70 mph were recorded atop squaw mountain…5 miles south of Idaho Springs… And at Rollinsville in the foothills southwest of Boulder. Northwest winds gusted to 28 mph at Stapleton International Airport.

From the 27th to the 28th:

In 1874…strong west winds in Boulder along with a reported tornado produced 150 dollars in damage.

In 1913…a strong cold front produced sustained northeast winds to 35 mph with gusts as high as 38 mph on the 27th. Overnight snowfall totaled 5.8 inches.  Temperatures plunged to a low of 17 degrees on the morning of the 28th after a high of 60 degrees on the 27th.

From the 27th to the 30th:

In 2009…a powerful early season storm brought heavy snow to the Front Range. The combination of a deep northeasterly upslope flow coupled with abundant moisture and lift with the developing storm system produced an extended period of moderate to heavy snowfall. The heavy wet snow accumulated on trees and resulted in broken branches and scattered electrical outages. Interstates 70 and 76 were closed east of Denver. Numerous other roads and highways were shut down. The Red Cross set up numerous emergency shelters for stranded travelers. The blowing snow at Denver International Airport forced the cancellation of hundreds of flights. Schools were also closed. In the foothills storm totals included: 46 inches… 3 miles southeast of Pinecliffe; 42 inches…3 miles southwest of Conifer; 34 inches…3 miles north of Blackhawk; 30 inches at Aspen Springs and near Evergreen… 23 inches at Roxborough Park…and 20 inches… 3 miles south-southeast of Morrison. Across the urban corridor storm totals included: 25 inches in Highlands Ranch; 21.5 inches near Louisville…20.5 inches in Broomfield… 20 inches at Lafayette…17.5 inches in Boulder… 17 inches in Westminster…16.5 inches in Erie; 15.5 inches in Arvada and 5 miles west-northwest of Littleton…15 inches in Littleton…14 inches in Englewood… 13.5 inches in Lakewood and 6 miles north of Thornton; 13.3 inches at Denver International Airport…11 inches… 4 miles south of Denver; 10.5 inches…2 miles north of Cherry Hills Village and Niwot.

On the 28th:

In 1917…post-frontal snowfall totaled 6.5 inches in the city.  North winds sustained to 30 mph with gusts to 33 mph caused the temperature to plunge from a high of 58 degrees to a low of 9 degrees by midnight.

In 1967…winds gusted to 65 mph in downtown Boulder… Causing minor damage.  South winds gusted to 32 mph at Stapleton International Airport.

In 1991…the first major snow of the season hit metro Denver as a cold arctic air mass moved over the area.  Snowfall amounts across northeast Colorado ranged from 3 to 10 inches with 4.4 inches of snowfall recorded at Stapleton International Airport where north winds gusted to 22 mph. The low temperature dipped to 13 degrees.

In 1993…high winds buffeted the Front Range foothills.  A wind gust to 83 mph was recorded atop squaw mountain…35 miles west of Denver…and a gust to 76 mph occurred near Rollinsville southwest of Boulder.

From the 28th to the 29th:

In 1993…an upper level disturbance combined with a moist upslope flow to bring heavy snow to portions of metro Denver.  Snowfall amounts ranged from 5.4 inches at Stapleton International Airport to 14 inches in Boulder. New snowfall totaled 8 inches at Gross Reservoir in the foothills 5 miles southwest of Boulder.  On the 28th…north winds gusted to 30 mph at Stapleton International Airport where the temperature climbed to only 25 degrees on the 29th…equaling the record low maximum for the date.

From the 28th to the 30th:

In 1971…a vigorous cold front plunged temperatures from a high of 70 degrees on the 27th to record low levels on the 29th and 30th.  Snowfall totaled 3.1 inches at Stapleton International Airport where north winds gusted to 23 mph. Some freezing drizzle also fell on the 28th.  Record daily low maximum temperatures of 32 degrees on the 28th and 25 degrees on the 29th were established along with a daily record minimum of 13 degrees on the 30th.

From the 28th to the 31st:

In 1929…rain changed to snow on the afternoon of the 28th and continued until midday on the 30th followed by intermittent light snow which continued through the 31st. Snowfall over the four days totaled 16.2 inches in the city.  Most of the snow…8.5 inches… Fell on the 29th with 6.1 inches on the 30th.  Temperatures hovered in 20`s during most of the storm.

On the 29th:

In 1917…the all-time lowest recorded temperature in October…2 degrees below zero… occurred.  This is also the earliest below zero reading of the season.

In 1939…the first measurable snow of the season totaled 5.6 inches in downtown Denver.  Post-frontal northeast winds were sustained to 28 mph.

In 1961…heavy snowfall measured 6.0 inches at Stapleton Airport where northeast winds gusted to 30 mph.

In 1973…strong winds caused some damage to homes…stores…  And utility lines along the foothills from metro Denver south.

In 1981…high winds buffeted the Front Range foothills with gusts to 55 mph in south Boulder.

In 1996…high winds gusting from 70 to around 100 mph blasted metro Denver.  One man was killed when a strong wind gust overturned a pop-up camper onto him while he was trying to secure it.  In addition…five people at the Rocky Flats Environmental Test Facility received minor injuries when several windshields were blown out of their cars…spraying glass onto the occupants.  Several trees and power lines were also downed.  Two 75-foot high pine trees were uprooted at the Mt. Olivet cemetery in Arvada.  Property damage from the windstorm ran into the millions of dollars.  The highest recorded wind gusts included:  101 mph at Jefferson County Airport near Broomfield…100 mph in Golden Gate Canyon… 96 mph in Coal Creek Canyon…and 87 mph at upper Table Mesa in Boulder.  West-northwest winds gusted to 43 mph at Denver International Airport.  Insured damage from the wind storm totaled 5.2 million dollars…the third most costly storm of record in Colorado at the time.

In 2003…strong Chinook winds developed in and near the Front Range foothills.  Winds gusting to 80 mph in Boulder downed several trees and power lines…causing damage and triggering scattered electrical outages.  The combination of strong winds…very dry fuel conditions… And downed power lines sparked two large wildfires.  The overland wildfire in Boulder County…near Jamestown… Consumed nearly 3900 acres and destroyed 12 structures…including homes…trailers… And out-buildings.  Preliminary damage estimates for the value of lost property was nearly one million dollars.  In Douglas County…the Cherokee Ranch Wildfire consumed 1200 acres and destroyed 4 structures.  The large smoke plumes from both fires were highly visible across metro Denver.  West winds gusted to 45 mph at Denver International Airport.

From the 29th to the 30th:

In 1905…heavy snowfall developed on the evening of the 29th and continued through the evening of the 30th.  Snowfall totaled 11.0 inches in downtown Denver.  Precipitation was 1.02 inches.  Temperatures were generally in the 20`s.

In 1959…rain during most of the day on the 28th changed to snow early on the 29th and continued through most of the 30th.  Heavy snowfall totaled 7.4 inches at Stapleton Airport.  North-northeast winds gusted to 24 mph on the 30th.  Some freezing drizzle also occurred on the 30th.

In 1981…4 to 8 inches of new snow were recorded in the foothills west of Denver.  Snowfall totaled only 0.4 inch at Stapleton International Airport where north winds gusted to 25 mph.

From the 29th to the 31st:

In 1889…the first snowfall of the season totaled 14.0 inches over the three days in downtown Denver.  Snowfall was 8.0 inches on the 29th and 5.0 inches on the 31st.  North to northeast winds gusted to 30 mph on the 29th.

In 1950…a warm spell resulted in five daily temperature records.  Record highs of 84…80… And 79 degrees occurred on the 29th…30th…and 31st… Respectively.  Low temperature of 49 degrees on the 30th was the record high minimum for the date.

In 1991…the second surge of cold arctic air in a matter of days plunged metro Denver into the deep freeze.  While low temperatures remained above zero…high temperatures were only in the 20`s.  Three temperature records were set: record lows of 7 degrees on the 30th and 10 degrees on the 31st and a record low maximum of only 21 degrees on the 30th.  Snowfall was light with only 1.9 inches recorded at Stapleton International Airport where east winds gusted to 23 mph.

In 2002…snowfall totaled 4.3 inches at the site of the former Stapleton International Airport.  North winds gusted to 32 mph on the 29th behind a cold front…which plunged temperatures well below seasonal normals.  High temperatures of 18 degrees on the 30th and 19 degrees on the 31st were record low maximums for each date.  Low temperatures dipped to 12 degrees on the 30th and 15 degrees on the 31st.

From the 29th to the 1st:

In 1972…heavy snowfall totaled 15.5 inches at Stapleton International Airport.  However…the heaviest snow occurred on Halloween night when 7 inches fell on trick-or-treaters during a short 3-hour period.  I-25 was closed south of Denver.  North winds gusting to 29 mph caused some blowing snow on the 1st.  The snow started late on the 29th and ended during the mid afternoon on the 1st.  The greatest snow depth on the ground at Stapleton International Airport was 13 inches on the 1st.

On the 30th:

In 1974…a rare thunderstorm for so late in October produced hail to 3/8 inch in diameter and 0.10 inch of rain at Stapleton International Airport.

In 1991…the high temperature warmed to only 21 degrees… The all-time record low maximum for the month of October.  The same temperature also occurred on October 25…1997.

On the 31st:

In 1997…high winds buffeted the foothills and adjacent areas of metro Denver.  West winds gusted to 70 mph in Broomfield and to 40 mph at Denver International Airport. The strongest winds occurred in the mountains west of Denver and in the foothills north of Denver.

In 2001…high winds developed in the foothills.  Peak wind gusts were measured to 74 mph at the National Center for Atmospheric Research on the mesa in Boulder and to 72 mph near Rollinsville.  West winds gusting as high as 53 mph warmed the temperature to a high of 71 degrees at Denver International Airport.

From the 31st to the 1st:

In 1951…6.4 inches of snowfall were measured at Stapleton Airport.

In 1989…a Halloween storm dropped 3 to 6 inches of snow on metro Denver with the adjacent foothills receiving 5 to 10 inches.  Snowfall totaled 4.5 inches at Stapleton International Airport…where north winds gusted to 31 mph on the 31st.  Most of the snow fell on the evening of the 31st…but the storm left icy streets throughout metro Denver on the morning of the 1st…making it a “spooky” commute for many motorists.

In 2004…heavy snow fell in and near the foothills of Jefferson and Douglas counties.  Storm total snowfall included:  14.5 inches in aspen park…10 inches at Roxborough State Park and near Sedalia…8 inches near Bergen Park… And 7 inches in Highlands Ranch.  Snowfall totaled only 3.2 inches in the Denver Stapleton area.  Post-frontal northeast winds gusted to 41 mph at Denver International Airport.

October 18 to October 24: This week in Denver weather history

This Week in Denver Weather History

This week is an extremely eventful one in Denver weather history with a wide variety of conditions having been experienced in the past. Wind and snow are probably the two most dominant items, none more so than the blizzard that struck 23 years ago on the 24th. That storm ravaged the city, closed the airport and highways and was responsible for four deaths.

From the National Weather Service:

From the 17th to the 19th:

In 1908…a moist…heavy…wet snowfall totaled 13.0 inches in downtown Denver over the 3 days. Rain from early morning on the 17th changed to snow by late afternoon and continued through the late morning of the 19th. Due to temperatures in the 30’s and melting…the most snow on the ground was only 5.0 inches at 6:00 pm on the 18th. Northwest to northeast winds were sustained between 12 and 20 mph during the storm. Precipitation totaled 1.82 inches.

On the 18th:

In 1875…the haze was so dense that the mountains were not visible from downtown Denver for most of the day.

In 1937…a vigorous cold front produced north winds sustained to 32 mph with gusts to 41 mph. Rain and snow totaled 0.16 inch. Post-frontal snowfall of 0.8 inch was the only snowfall of the month.

In 1960…post-frontal upslope rain changed to snow. Snowfall was 2.2 inches at Stapleton Airport where precipitation (rain and melted snow) totaled 1.58 inches.

In 1971…wind gusts to 48 mph were recorded in downtown Boulder. West winds gusted to 30 mph at Stapleton International Airport.

In 1999…heavy snow developed in the foothills west of metro Denver with lesser amounts across the city. Snowfall totals included: 7 inches near Nederland…6 inches in Boulder…and 5 inches at Chief Hosa. Only 1.2 inches of snow were measured at the site of the former Stapleton International Airport.

From the 18th to the 23rd:

In 2003…an extended warm spell resulted in 5 new temperature records. The high temperature of 84 degrees on the 18th equaled the record high for the date. High temperatures of 86 degrees on the 19th…83 degrees on the 21st…and 84 degrees on the 22nd were record highs for the dates. Low temperature of 49 degrees on the 23rd was a record high minimum for the date. Low temperatures during the period were in the 40’s and lower 50’s.

On the 19th:

In 1887…northwest winds sustained to 42 mph were recorded in the city.

In 1982…3 to 6 inches of snow fell over northwest metro Denver…including Boulder. Only 1.2 inches of snowfall were recorded at Stapleton International Airport where north winds gusted to 35 mph. This was the first measurable snowfall of the season.

From the 19th to the 20th:

In 1990…an early winter storm dumped heavy snow across metro Denver. Snowfall amounts ranged from 4 to 8 inches in the foothills above 6500 feet elevation…4 to 7 inches in the Castle Rock area…and 2 to 5 inches across most of metro Denver and Boulder. Snowfall totaled 3.6 inches at Stapleton International Airport where northwest winds gusting to 48 mph kicked up some blowing dust shortly after a cold frontal passage on the 19th. However… Temperatures were warm enough to keep most roadways wet and slushy at lower elevations.

From the 19th to the 23rd:

In 1906…heavy snowfall totaled 22.7 inches in the city over the 5 days. Rain changed to snow on the evening of the 19th…and snow continued through the late afternoon of the 23rd. The heaviest amount of snowfall…16.0 inches…fell from 8:00 pm on the 20th to 8:00 pm on the 22nd. The most snow on the ground was 13.3 inches on the evening of the 23rd. This was the first snow of the season and the only snow of the month. Winds during the storm were from the north at sustained speeds of 20 to 30 mph each day. Temperatures during the storm were generally in the 20’s.

On the 20th:

In 1878…between 3:00 pm and 4:00 pm wind speeds averaged 48 mph with a maximum 1 minute sustained velocity to 96 mph at both 3:27 pm and 3:48 pm in downtown Denver. This is the highest sustained wind speed ever recorded in the city.

In 1986…a rare late October thunderstorm produced 3/4 inch diameter hail at Centennial Airport. Hail piled up 2 1/2 inches deep…causing some street flooding in south metro Denver.

From the 20th to the 21st:

In 2007…a storm system brought heavy snow to the southern Denver suburbs as well as the Palmer Divide south of Denver. Storm totals included: 7.5 inches near Castle Rock…Lone Tree and Greenwood Village…with 6.5 inches at Elizabeth. Snow drifts up to 2 feet deep were observed 6 miles south-southwest of Elizabeth. In the Denver Stapleton area…2.0 inches of snow was observed.

In 2009…heavy snow developed along the Palmer Divide south and southeast of Denver as a storm system tracked across southern Colorado and northern New Mexico. Storm totals included: 15 inches…15 miles north of Elizabeth…9 inches… 5 miles south-southwest of Arapahoe Park; 8 inches in Highlands Ranch…5 miles south- southeast of Sedalia; 6.5 inches…8 miles southwest of Bennett and 6 inches in Parker. At Denver international… Only 1.5 inches of snowfall was observed.

From the 20th to the 22nd:

In 1936…5.5 inches of snow fell over downtown Denver. Most of the snow…4.5 inches…fell on the 20th.

On the 21st:

In 1920…the rare event of snow from a thunderstorm occurred in the city during the evening. Brilliant flashes of lightning and loud peals of thunder were first noted at 7:35 pm. Light rain began falling at 8:30 pm…and light moist snow began falling a few minutes later. Some soft hail was also seen falling with the rain and snow…but both melted almost as fast as they fell. The hail only continued for a few minutes…and the rain and snow ceased about 9:40 pm. The snowfall was the first to occur in Denver this season. The amount of precipitation at the station measured only 0.01 inch…but heavier amounts were reported from other parts of the city. Snowfall was only a trace.

From the 21st to the 22nd:

In 1978…heavy rain on the 21st changed to snow by daybreak on the 22nd and continued the rest of the day. This was the first measurable snowfall of the season…but totaled only 1.7 inches at Stapleton International Airport where east winds gusted to 29 mph. While only a trace of snow covered the ground…precipitation totaled 1.27 inches.

On the 22nd:

In 1878…winds were sustained to 42 mph.

In 1887…the first measurable snow of the season occurred… Ending the longest snow-free period in Denver…232 days… Since the last snow on march 5th.

In 1947…the first snow of the season totaled only 1.6 inches. Post-frontal north winds caused temperatures to plunge from a high of 60 degrees at midnight to a low of only 30 degrees 24 hours later. This was the only snow of the month.

In 1985…high winds gusting from 60 to 80 mph buffeted the Front Range foothills. The strongest reported wind gust was 89 mph in eastern Boulder. A treehouse east of Boulder was set on fire by a downed power line. Two people in Boulder were injured. A woman broke her arm when the strong winds knocked her to the ground. A carpenter in the city suffered a severely cut hand while he was trying to repair a roof that was being torn from a building. At Stapleton International Airport…northwest winds gusted to 41 mph.

In 2001…west-northwest winds gusting as high as 54 mph warmed the temperature to a high of 70 degrees at Denver International Airport.

Continue reading October 18 to October 24: This week in Denver weather history

October 11 to October 17: This week in Denver weather history

This Week in Denver Weather History

A very eventful week of weather in Denver weather history. Many notable items have occurred and many also incorporate one of two conditions – wind or snow. Probably the most famous event was the Bronco Blizzard on October 15, 1984. That storm which hit its height during a Monday Night Football game between the Broncos and the Packers is probably one of the most memorable ever for longtime Denver residents.

From the National Weather Service:

10-11

In 1986…the first significant snowstorm of the season produced 2 to 5 inches of snow over metro Denver with 5 to 10 inches in the foothills west of Denver. Wondervu recorded the most snow from the storm…13 inches. The heavy wet snow caused numerous power outages. The storm was accompanied by strong north winds with gusts to 41 mph recorded on the 10th. The first snowfall of the season totaled 3.1 inches at Stapleton International Airport with only one inch on the ground due to melting. The strong cold front accompanying the storm cooled the temperature from a high of 73 degrees on the 10th to a high of only 33 degrees on the 11th…which was a record low maximum for the date.

10-12

In 1969…the second heavy snowstorm in less than a week dumped nearly a foot of snow across metro Denver and plunged the area into extremely cold temperatures for so early in the season. Snowfall totaled 11.0 inches at Stapleton International Airport. North winds gusting to 26 mph produced drifts up to 2 feet deep. Temperatures dipped from a high of 52 degrees on the 10th to a record low for the date of 10 degrees on the 12th. There was additional damage to trees and power and telephone lines from heavy snow accumulations and icing. Travel was restricted or blocked by drifting snow in both the mountains and on the plains east of Denver.

11

In 1997…damaging winds ahead of an approaching storm system developed in the foothills and spread across metro Denver. Winds gusted to 88 mph at Conifer…71 mph at the National Center for Atmospheric Research on the mesa in Boulder… And 53 mph at Denver International Airport. Several trees and street signs were blown down with scattered power outages reported throughout metro Denver. In Arvada…a car window was blown out by a strong wind gust.

In 2013…high winds occurred in and near the Front Range foothills. Peak gusts included: 85 mph at Rooney Road… 84 mph…2 miles south of Marshall; 82 mph at Rocky Flats National Wind Technology Center and Wondervu; 79 mph at the mesa lab at NCAR and 75 mph…3 miles south-southwest of Boulder; 73 mph in superior and 68 mph in Golden. The wind downed trees and power lines. As a result…scattered electrical outages affected 20000 xcel energy customers through the morning hours. The main outages affected the cities of Boulder…Golden and Lakewood. Smaller outages were reported in areas of Gold Hill…Ward… Westminster and Wheat Ridge.

11-12

In 1901…an apparent cold front produced northeast winds sustained to 42 mph with gusts to 48 mph on the 11th. General rain changed to snow overnight and totaled 2.0 inches. This was the first snowfall of the season. Total precipitation was 0.32 inch.

11-13

In 1892…apparent post-frontal rainfall totaled 3.33 inches in downtown Denver over the 3 days. A trace of snow on the 12th melted as it fell. Rainfall of 2.58 inches on the 12th into the 13th was the greatest 24-hour precipitation ever recorded during the month of October. Northwest winds were sustained to 48 mph with gusts as high as 55 mph on the 12th.

12

In 1873…smoke from several very large forest fires was sighted along the mountains.

In 1923…post-frontal rain changed to snow and totaled 4.0 inches. North winds were sustained to 14 mph.

In 1978…northeast winds gusting to 35 mph with a strong cold front briefly reduced visibility to 2 miles in blowing dust at Stapleton International Airport.

12-13

In 2001…overnight peak wind gusts to 82 mph and 70 mph were measured atop Niwot Ridge and Squaw Mountain… Respectively.

12-14

In 1969…record breaking extremely cold temperatures for so early in the season occurred. The high temperature of 26 degrees on the 13th was two degrees lower than the previous record minimum temperature of 28 degrees for the date set in 1885. The high temperature of 24 degrees on the 12th exceeded the record low temperature (22 degrees set in 1885) for the date by only 2 degrees. In addition… 3 new record low temperatures for the dates were set. The low temperature dipped to 10 degrees on the 12th breaking the old record (22 degrees in 1885) by 12 degrees. On the 13th the mercury plunged to a low of 3 degrees breaking the old record (28 degrees in 1885) by 25 degrees. On the 14th the temperature reached a minimum of 4 degrees breaking the old record (25 degrees in 1966) by 21 degrees.

13

In 1990…strong downslope winds stirred up clouds of dust and gravel…rattled windows…and stripped autumn-colored leaves from trees in Boulder. A wind gust to 78 mph was clocked in southwest Boulder…while a 96 mph gust was recorded in northwest Boulder. West winds gusted to only 36 mph at Stapleton International Airport.

13-14

In 1910…light smoke from nearby forest fires drifted over the city.

In 1966…the first measurable snow of the season caused widespread damage to trees and shrubs. The heavy wet snow totaled 6.9 inches at Stapleton International Airport where north-northwest winds sustained at 20 to 25 mph and gusting to 45 mph caused much blowing and drifting snow. South and east of Denver…up to a foot of snow fell. Heavy wet snow accumulations followed by freezing temperatures and strong winds resulted in extensive damage to trees…cars… And utility lines by falling limbs. A woman was killed by a falling snow laden tree limb in Denver. Several other people received minor injuries from falling tree limbs.

In 1987…rain drenched metro Denver. The South Platte Canyon area southwest of Denver received the most with 1.11 inches at Kassler and 1.49 inches upstream at Strontia Springs. At Stapleton International Airport…0.62 inch of rain was measured…northwest winds gusted to 29 mph…and thunder was heard.

In 2007…a new 24-hour record of 2.65 inches of precipitation was set at Denver International Airport for the month of October; breaking the previous record of 2.58 inches set in 1892.

13-16

In 1873…smoke from several large forest fires in the mountains made the air very hazy in the city.

14

In 1952…the first measurable snowfall of the season left 1.2 inches of snow at Stapleton Airport. North winds gusted to 38 mph.

In 1974…rain changed to snow early in the day…but snowfall totaled only 1.0 inch at Stapleton International Airport where northeast winds gusted to 20 mph.

15

In 1871…a terrible wind occurred during a snow storm in the foothills above Boulder. Damage was minor.

In 1878…high winds reached sustained speeds of 60 mph at times.

In 1911…post-frontal northwest winds were sustained to 41 mph with gusts to 43 mph.

In 1948…strong winds struck the Boulder area. Winds averaged 50 mph at valmont just east of Boulder. Wind gusts in excess of 60 mph were recorded at the Boulder airport. Wind gusts to 40 mph briefly reduced the visibility to 1 1/2 miles in blowing dust at Stapleton Airport.

In 1980…a rare October tornado touched down in Boulder… Damaging a vocational training building and throwing three nearby cars together damaging them extensively. A mile and half away several camper vehicles were thrown 200 feet. The storm also produced 1 inch diameter hail in the Boulder area.

15-16

In 1928…a thunderstorm produced hail shortly after midnight on the 15th. Rain changed to snow by evening. Through the afternoon of the 16th…the heavy snowfall totaled 7.3 inches in the city. North winds were sustained to 23 mph on the 15th.

In 1984…the heaviest October snowstorm in several years hit eastern Colorado with a vengeance. The storm was known as the “Bronco Blizzard” since it occurred during a nationally televised Monday night football game in Denver. One to two feet of snow fell near the foothills in west metro Denver with 2 to 3 feet in the foothills. Wind gusts up to 55 mph whipped the snow into drifts as high as 4 feet. The storm closed schools…roads…and airports. I-70 was closed both east and west of Denver. I-25 was closed south to Colorado Springs. Flights were delayed for several hours at Stapleton International Airport. Power outages were widespread. Snowfall totaled 9.2 inches at Stapleton International Airport where north winds gusting as high as 40 mph caused frequent surface visibilities of 1/4 to 1/2 mile in moderate to heavy snow and blowing snow overnight. The high temperature of only 35 degrees on the 15th was a record low maximum for the date.

15-17

In 1989…an autumn snowstorm hit metro Denver with 2 to 6 inches of snow. Snowfall totaled 4.4 inches at Stapleton International Airport where the maximum snow depth on the ground was only 3 inches due to melting and north winds gusted to 25 mph on the 15th. The heavy wet snow caused leafy branches to sag onto power lines…resulting in a number of power outages. Five thousand homes were blacked out in Boulder on the 16th. Up to a foot of snow fell in the higher foothills with 19 inches recorded at Echo Lake.

16

In 1878…high winds reached sustained speeds of 60 mph.

In 1998…one of the costliest hail storms to ever hit metro Denver caused an estimated total of 87.8 million dollars in damage to homes…commercial buildings…and motor vehicles. At the time the storm was ranked as the 7th costliest ever. The hailstorm…rare for so late in the season…began over portions of Arvada…Wheat Ridge…and northwest Denver where mostly pea sized hail accumulated up to a depth of 6 inches near I-70. Several accidents were attributed… At least in part…to the hailstorm. Snowplows had to be called out to clear several city streets. The storm intensified as it moved to the east…into the Denver and Aurora areas. Large hail…up to 2.00 inches in diameter pounded east and southeast metro Denver. Two inch diameter hail fell in the city of Denver and at Buckley Field. Hail as large as 1 1/2 inches was measured in south Denver with 1 inch diameter hail in northern Aurora.

In 1999…upslope conditions produced snow across metro Denver with heavy amounts in the nearby foothills. Snowfall totals included: 9 inches at Eldorado Springs; 8 inches at Genesee… Golden gate canyon…Littleton and near Morrison; 7 inches near Nederland; and 6 inches in Louisville. Snowfall totaled 3.6 inches at the site of the former Stapleton International Airport.

16-17

In 1990…strong downslope winds raked the eastern foothills. Wind gusts from 60 to 75 mph were common. Strong winds in metro Denver resulted in wave damage to a dock used to moor several private sail boats at Cheery Creek Reservoir. Damage was confined to the dock and two anchor cables. A northwest wind gust to 43 mph was recorded at Stapleton International Airport.

17

In 1878…strong winds reached sustained speeds of 48 mph.

In 1988…a wind gust to 62 mph was recorded in central Boulder. The strong winds caused a few brief power outages. An old smoldering brush fire in the foothills west of Boulder was re-ignited by the wind gusts.

In 1994…winds gusted to 85 mph atop Squaw Mountain…5 miles south of Idaho Springs.

In 2006…a potent storm system brought heavy snowfall to the mountains and eastern foothills. Snowfall totals in the foothills included: 14 inches at Blackhawk…13.5 inches near Idaho Springs…13 inches at Cabin Creek…12.5 inches at aspen springs and Echo Lake…11.5 inches at Georgetown and Rollinsville…10.5 inches near Jamestown…and 10 inches at Grant and Lake Eldora. Lesser snow amounts…from 4 to 9 inches…were recorded elsewhere in the foothills. Snowfall totaled only 3.5 inches in the Denver Stapleton area. At Denver International Airport…north winds gusted to 31 mph.

In 2012…a brief but powerful windstorm associated with a fast moving cold front across the urban corridor and adjacent plains during in the evening. Peak wind gusts ranging from 58 to 71 mph downed trees and power lines which damaged homes and vehicles. Several temporary structures were also damaged. Approximately fifty thousand were left without power in the Denver…Fort Collins and Greeley areas. Some schools were closed the following day until power could be restored. Around the Denver area…peak wind gusts included: 69 mph in Golden…64 mph at Littleton…  62 mph at Buckley AFB and in Denver…near the intersection of Walnut St. and interstate 25…and Longmont; 59 mph at Centennial Airport…58 mph at Denver City Park… Highlands Ranch.  At Denver International Airport…a peak wind gust to 35 mph was observed from the northwest.

17-19

In 1908…a moist…heavy…wet snowfall totaled 13.0 inches in downtown Denver over the 3 days. Rain from early morning on the 17th changed to snow by late afternoon and continued through the late morning of the 19th. Due to temperatures in the 30’s and melting…the most snow on the ground was only 5.0 inches at 6:00 pm on the 18th. Northwest to northeast winds were sustained between 12 and 20 mph during the storm. Precipitation totaled 1.82 inches.

October 4 to October 10: This week in Denver weather history

This Week in Denver Weather History

A very eventful week in Denver weather history with a wide variety of events from snow to summer-like severe weather. Most notable is five years ago today when multiple tornadoes touched down in the Brighton area.  Read more about all the events below and scroll to a bottom for videos of the 2004 tornadoes.

From the National Weather Service:

From the 3rd to the 4th:

In 1969…the first snowfall of the season totaled 16.0 inches at Stapleton International Airport. There was a thunder snow shower on the evening of the 3rd…but otherwise little wind with the storm. The greatest snow depth on the ground was 8 inches due to melting. Heavy wet snow accumulated on trees…which were still in full leaf…and caused widespread damage from broken limbs and downed utility lines.

From the 3rd to the 5th:

In 1984…the remnants of pacific hurricane polo produced heavy rain over northeastern Colorado. Most locations received between 1.00 to 2.50 inches of rain…but 3.45 inches fell in Littleton. Rainfall totaled 1.73 inches at Stapleton International Airport…where north winds gusted to 24 mph.

On the 4th:

In 1912…sustained south winds to 55 mph with gusts to 60 mph raised the temperature to a high of 83 degrees… The warmest temperature of the month that year.

In 1924…west winds were sustained to 46 mph with gusts to 50 mph in the city. The apparent Bora winds cooled the temperature to a high of 57 degrees from a high of 70 degrees on the 3rd.

In 2004…several small tornadoes touched down near Brighton… Barr lake…and Hudson in Adams and southern weld counties. Most of these caused no damage. However…a small tornado 5 miles southeast of Brighton caused extensive damage to a recreational vehicle and severely damaged a barn. The barn was torn from its foundation…and the roof was thrown 100 feet. Four llamas in the barn were injured when it collapsed.

From the 4th to the 5th:

In 1997…unusually warm weather resulted in two temperature records. High temperature of 87 degrees on the 4th exceeded the old record set in 1922 by one degree. High temperature of 86 degrees on the 5th equaled the record set in 1990 and previous years.

On the 5th:

In 1962…unusually severe thunderstorms for this late in the season affected areas from Boulder northward. Hail up to golf ball size and strong gusty winds did much damage to roofs…windows…and signs in Boulder. Heavy rainfall caused local flooding.

In 1994…lightning caused a power outage to over 2400 homes for a few hours in and around Nederland in the foothills southwest of Boulder. Very strong winds accompanied the thunderstorm. Thunderstorm winds gusted to 60 mph and hail to 1/2 inch diameter fell in Lafayette. Strong microburst winds gusting to 69 mph near Strasburg caused an oil rig to topple onto two vehicles…injuring one person. The strong winds in the area also downed a few power poles… But caused power outages to only a few homes.

In 1995…strong winds spread from the foothills onto the plains. Wind gusts to 77 mph were reported atop squaw mountain west of Denver. On the plains…winds gusted to 60 mph at Kennesburg and to 62 mph near Strasburg. North winds gusted to 41 mph at Denver International Airport.

On the 6th:

In 1900…northwest winds were sustained to 40 mph with gusts as high as 50 mph in downtown Denver.

In 1903…northwest winds were sustained to 40 mph with gusts to 50 mph. The strong winds warmed the temperature to a high of 71 degrees in the city. The low reading was only 46 degrees.

In 1910…light smoke from forest fires drifted over the city.

In 1976…an arctic cold front brought light snow over the foothills above 6 thousand feet. Traffic was snarled at many locations. Only a trace of snow fell at Stapleton International Airport where rainfall totaled 0.20 inch and northeast winds gusted to 41 mph.

In 1991…the brilliant orange sunset was apparently the result of an extensive volcanic smoke layer in the upper atmosphere.

In 1994…strong west to northwest winds developed in the foothills above 9500 feet. A wind gust to 78 mph was recorded atop squaw mountain west of Denver and to 72 mph at ward northwest of Boulder. Northwest winds gusted to 35 mph at Stapleton International Airport.

In 2011…strong winds developed in and around the Denver area ahead of an approaching storm system. At the National Wind Technology Center…peak wind gusts ranged from 79 to 92 mph during the early morning hours. Across metro Denver…the strong winds toppled a few trees and damaged patio furniture. The wind caused a few flight delays at Denver International Airport due to a partial ground stoppage of incoming flights. Peak wind reports also included: 66 mph at Cedar Point…63 mph at Denver International Airport…60 mph at Buckley Air Force Base; 59 mph at Highlands Ranch; 58 mph at Deer Trail and Rocky Mountain Metro Airport in Broomfield; 55 mph at Bennett…Centennial Airport and City Park in Denver.

On the 7th:

In 1903…north winds were sustained to 40 mph with gusts to 48 mph.

In 1917…post-frontal northwest winds were sustained to 45 mph with gusts to 52 mph. Rain was mixed with a trace of snow…the first of the season. Precipitation totaled 0.22 inch and included the occurrence of hail even though no thunder was heard.

In 1950…strong winds caused a power outage in Boulder. This was the heaviest windstorm since January. Damage was minor. Northwest winds gusted to only 35 mph at Stapleton Airport.

In 1985…strong Chinook winds buffeted the Front Range foothills. Wind gusts between 60 and 70 mph were reported in Boulder and atop squaw mountain west of Denver. Southwest winds gusted to 41 mph at Stapleton International Airport.

From the 7th to the 8th:

In 1990…the season’s first snow occurred. Snowfall amounts varied from 3 to 7 inches across metro Denver. Snowfall totaled 4.0 inches at Stapleton International Airport where north winds gusted to 29 mph.

Continue reading October 4 to October 10: This week in Denver weather history

September 27 to October 3: This week in Denver weather history

This Week in Denver Weather History

With the end of summer and the arrival of fall, looking back at Denver weather history we start to see more mentions of snow.  It is of course not the only notable weather event this time of year.  We still have received severe thunderstorms, damaging winds, and 90 degree plus heat.

From the National Weather Service:

From the 25th to the 27th:

in 1996…an early season snowstorm brought heavy snow to the Front Range eastern foothills.  Snowfall totals included:  8 to 12 inches around Conifer…7 inches on Floyd Hill…and 6 inches at both bailey and Chief Hosa. Snowfall totaled only 4.7 inches at the site of the former Stapleton International Airport.  This was the first measurable snow of the season.  After the passage of a strong cold front…north winds gusted to 38 mph at Denver International Airport on the 25th.

From the 26th to the 28th:

In 1936…the heaviest snowfall ever recorded in September and the heaviest snowfall ever recorded so early in the season dumped a total of 16.5 inches of snow on downtown Denver and 21.3 inches at Denver municipal airport.  The 15.0 inches of snow measured from 6:00 pm on the 27th to 6:00 pm on the 28th is the greatest 24 hour snowfall ever recorded in September.  This was the first snow of the season.  The snow was intermittent through the 26th…but continuous from early afternoon on the 27th to around midnight on the 28th…except for a period of rain during the afternoon of the 28th which contributed to a loss of depth on the ground.  The greatest snow depth on the ground downtown was 13 inches with 8 inches at Denver municipal airport.  There were no high winds with the storm and traffic was interrupted for only a short period.  The storm produced property damage estimated at 7 million dollars.  With trees and shrubs in full foliage…the leaves caught and held the heavy water-laden snow…until the branches snapped from the weight.  More than 3000 workmen were called to remove the debris and snow from the city.  The city firemen who were off duty…as well as all the reserves… Were asked to report to their stations.  All schools in the city remained open…but attendance was only 50 percent of normal.  Grade school students were sent home at noon on the 28th.  The early storm caught stockmen with many cattle still in higher ranges.  Warm weather followed the snow…which had all melted by the end of the month…except for a few inches in sheltered places.

On the 27th:

In 1877…smoke from heavy forest fires in the mountains spread over the city on upper wind currents.

In 1935…the first snow of the season was 2.8 inches in downtown Denver.  The low temperature dipped to 31 degrees for the first freeze of the season.

From the 27th to the 28th:

In 1984…heavy snow fell over the plains and foothills. Snowfall amounts ranged from 2 to 5 inches on the plains with up to a foot at higher elevations in the foothills. The main problem caused by the storm was thousands of power outages caused by snow-laden tree limbs snapping and falling onto power lines.  Over 15 thousand homes lost power in metro Denver.  Some cars were damaged by falling trees and limbs.  The snow also caused some flight delays at Stapleton International Airport where 5.1 inches of snow fell and northeast winds gusted to 29 mph.  Maximum snow depth on the ground was 3 inches due to melting.  The high temperature of only 34 degrees on the 28th was a record low maximum for the date and equaled the all-time record for the month at that time.

On the 28th:

In 1877…heavy dense smoke from mountain forest fires spread over the city.  The smoke was so dense that it obscured the sun at times.

In 1921…post-frontal northeast winds were sustained to 44 mph.

In 1953…a pacific cold front produced a west wind gust to 59 mph at Stapleton Airport where the visibility was briefly reduced to 3/4 miles in blowing dust.  Strong winds were also widespread over Boulder during the afternoon.

In 1960…strong…gusty winds tore the roof from 6 units of a motel on west Colfax Avenue in Denver.  The roofing sailed over the building and crashed down on a truck…wrecking it. The strong winds were the result of an apparent microburst.

In 1999…snow fell in the foothills west of metro Denver and over the plains.  Snowfall totals included 7 inches at Conifer.  At the site of the former Stapleton International Airport…3.1 inches of snow were measured.  This was the first snow of the season.  The heavy wet snow snapped branches from fully leafed trees…downing power lines and causing scattered outages.

In 2004…severe thunderstorms produced hail to 3/4 inch in diameter in Littleton and in Douglas County 14 miles northwest of Castle Rock.

In 2012…a weak tornado (ef-0) tornado touched down near Strasburg. No damage was reported.

From the 28th to the 29th:

In 1959…one of the heaviest September snow storms of record began as rain and changed to heavy wet snow.  The storm caused heavy damage to trees and shrubbery…which were still in full leaf.  The storm dumped 10.6 inches of snow at Stapleton Airport…the third heaviest September snow amount to date.  Falling trees and limbs disrupted traffic…broke power and communication lines…and damaged buildings and cars.  One man was killed in Denver by a falling tree limb…and four others died of heart attacks while shoveling snow or trying to move heavy tree limbs.  Direct costs of the storm for cleaning up debris…repairing utility lines…and damage to buildings and other property across all of eastern Colorado were estimated to be over a half million dollars.  The value of trees destroyed or damaged was estimated to exceed five million dollars.  North-northeast winds gusted to 32 mph at Stapleton Airport on the 28th.

In 1985…an unusually cold air mass for this time of year settled over the area.  Metro Denver received 8 to 12 inches of powdery snow.  The 8.7 inches of snow that fell at Stapleton International Airport was the first measurable snow of the season and the city’s heaviest September snowfall since 1971.  The snow caused flight delays of over 2 hours at Stapleton International Airport. I-70 was closed for a time west of Denver.  Snow-laden tree limbs snapped over all of metro Denver…causing widespread power outages.  Ten thousand people were without electricity for a time in Boulder.  The morning of the 29th saw mid-winter temperatures along the Front Range.  The temperature dipped to 17 degrees…the lowest temperature ever recorded in September in Denver.  The high temperature of only 29 degrees on the 29th was a new record low maximum for the date and lowest ever recorded during the month of September.  The low temperature of 21 degrees on the evening of the 28th set a new record low for the date.  The cold weather persisted through the 1st with record minimum temperatures of 25 degrees set on the 30th and 27 degrees set on October 1st.

On the 29th:

In 1966…a vigorous cold front moved thru metro Denver. North winds gusting to 51 mph kicked up billows of blowing dust…which briefly reduced the visibility to 1 mile at Stapleton International Airport.  The cold air caused temperatures to drop rapidly from a high of 86 degrees to a low of 46 degrees by days end.

In 1985…the lowest temperature ever recorded in September… 17 degrees…occurred.  The high temperature warmed to only 29 degrees…the all-time record low maximum for the month.

In 1994…the temperature reached a high of 91 degrees at Stapleton International Airport.  This was the 60th day of the year that the temperature had reached 90 degrees or more…establishing a new record at that time.  The previous record of 52 “90 degree days” occurred in 1978. Only 43 “90 degree days” were recorded at Denver International Airport during 1994.

In 1995…lightning struck a couple in Aurora as they were walking in the rain.  The bolt struck the umbrella the man was carrying…injuring both the man and his wife.

In 2000…late afternoon thunderstorms produced strong wind gusts to 76 mph in Westminster…to 69 mph near Boulder…and to 60 mph at Jefferson County airport near Broomfield.  No damage was reported.

In 2014…a storm system that moved through the area produced large hail and street flooding in parts of metro Denver and then spread east into the plains. The storm also caused multiple accidents. A semi became detached from a trailer… Blocking traffic on westbound Interstate 70 west of Tower Road. Downed power poles blocked a roadway on CO 79 near Bennett…at mile marker 10. In addition to the damaging winds…the storms produced large hail… From nickel to golfball size across southern and eastern portions of metro Denver. The hailstorm was the most damaging of the 2014 summer season…with insured losses that topped 213 million dollars. Insurance claims included 29297 automobile claims worth more than 87.2 million dollars and 14287 property claims for 126 million dollars…ranking the storm as the eighth most expensive to hit the state. At Denver International Airport…1.01 inches of rainfall was recorded which was the greatest 24-hr rainfall for the date. In addition…a peak wind gust to 38 mph was observed at the airport.

In 2015…severe thunderstorms developed over the foothills of Boulder County and Jefferson Counties…then moved south along the western suburbs of Denver. Areas north of Golden… around Lakewood and into northern Douglas County saw the heaviest rain and hail. The hail ranged in size from nickel to ping pong size.

On the 30th: Continue reading September 27 to October 3: This week in Denver weather history

September 20 to September 26: This week in Denver weather history

This Week in Denver Weather History

Looking back at this week in Denver history we start to see more of the signs that summer is coming to an end and fall and winter are right around the corner.  Summer-like severe weather can still occur but we also start to see more cold temperatures and occasions with snow become more prevalent.

From the National Weather Service:

20

In 1921…an apparent Bora produced northwest winds sustained to 44 mph with gusts to 64 mph.

In 1955…hail stones 1/2 to 3/4 inch in diameter were reported across parts of the city of Denver.

In 1992…weather observers at Buckley Air National Guard base sighted two tornados southeast of the base.  The tornados were short-lived and caused no injuries or damage.

20-21

In 1963…heavy rain and hail caused local flooding in southeast Denver.  Thunderstorm rainfall was only 0.60 inch at Stapleton Airport on the 20th.

In 1983…the cold front on the 19th brought an unusually cold air mass into metro Denver for so early in the season.  The temperature dipped to a daily record minimum of 28 degrees on both days.

In 1995…a vigorous late summer storm brought the season’s first heavy snow to portions of metro Denver.  Millions of trees were damaged and power lines downed as 4 to 8 inches of heavy wet snow settled on fully leafed trees in the Boulder and Denver areas.  Branches snapped and trees split under the weight of heavy snow…downing power lines. Firefighters responded to numerous transformer fires. Around 100 thousand people were left without electricity in Boulder and Denver areas alone.  It took over a week to fully restore power to some areas.  Insurance claims were estimated to be around 6 million dollars to homes in metro Denver and about 500 thousand dollars in damage to automobiles.  It was estimated that about 80 percent of 125 million dollars worth of city owned trees in Denver were damaged.  Snowfall totaled 7.4 inches at the site of the former Stapleton International Airport where the greatest depth of snow on the ground was only 4 inches due to melting.  Temperature records were set on the 21st when the thermometer dipped to a record low reading of 27 degrees and climbed to a high of only 36 degrees… Setting a record low maximum for the date.  North winds gusted to 29 mph at Denver International Airport on the 20th.

20-22

In 1902…a thunderstorm on the 20th…in advance of an apparent cold front…produced rain…hail…and northwest winds to 40 mph with gusts to 48 mph.  Widespread rain developed behind the cold front and totaled 3.21 inches from the evening of the 20th through the early afternoon of the 22nd.  The 2.70 inches of precipitation recorded from 800 pm on the 20th to 800 pm on the 21st is the greatest 24 hour precipitation ever recorded in the month of September.  The temperature dipped from a high of 80 degrees on the 20th to a high of only 51 degrees on the 21st.

21

In 1951…4.2 inches of snow fell at Stapleton Airport… Where northeast winds gusted to 27 mph.  This was the first snowfall of the season in Denver…marking the end of the second shortest snow-free period on record…109 days…from June 4th through September 20th.  A trace of snow fell on June 3rd.

In 1984…thunderstorm winds gusted to 56 mph at Stapleton Airport.

In 1992…the only precipitation of the month at Stapleton International Airport…0.01 inch of rain…fell from a brief shower around daybreak.
21-22 in 1870…strong winds occurred in the foothills and in Boulder and Denver.

In 1895…rain changed to snow overnight and totaled 11.4 inches in downtown Denver.  This was the first snowfall of the season and the second heaviest first snowfall of the season on record.  North winds were sustained to 27 mph with gusts to 30 mph on the 21st.

In 2009…an early season storm brought moderate to heavy snow to the foothills of clear creek…Jefferson and Park counties…west and southwest of Denver. A trained spotter…4 miles west-northwest of Conifer… Was the big winner with 14 inches of snow. Storm totals elsewhere generally ranged from 5 to 10 inches.

22

In 1913…a thunderstorm produced northwest winds sustained to 40 mph with gusts to 44 mph.

In 1946…a trace of snow fell in downtown Denver.  This marked the start of the longest snow season on record… 263 days through June 11…1947…when a trace of snow also fell.

Continue reading September 20 to September 26: This week in Denver weather history

September 13 to September 19: This week in Denver weather history

This Week in Denver Weather History

Weather conditions in Colorado can of course vary greatly and we always see that in our weekly look back in the history books.  For this week, we see a dizzying array of weather events from record setting temperatures in the 90’s and summer-like thunderstorms with tornadoes to an early arrival of winter that brought a foot of snow!

From the National Weather Service:

5-13

In 2010…the Fourmile Canyon wildfire…northwest of Boulder… Broke out on the morning of the 5th. It originated from an unattended fire pit at a local residence. The wildfire quickly consumed 5 1/2 square miles or 3500 acres the first day…and forced the evacuation of over three thousand residents. Erratic 45-mph gusts sent the fire in two directions at times. Very dry weather conditions preceded the fire. The combination of strong winds…low relative humidities and dry fuels allowed the wildfire spread rapidly through the steep…heavily forested terrain. The flames were reportedly 20 to 50 feet in length. Towns within the burn area included Salina…Wallstreet and Gold Hill. The dry conditions coupled with gusty winds ranging from 45 to 64 mph persisted for several more days. Fire managers used as many as 700 firefighters and support personnel from 35 agencies and seven air tankers to battle the wildfire. A total of 6181 square acres or approximately 10 square miles were burned. The Fourmile Canyon wildfire was the most destructive fire in Colorado history in terms of the damage to personal property. It destroyed 171 homes with an estimated cost of 217 million dollars.

11-16 in 2013…a deep southerly flow over Colorado… Ahead of a nearly stationary low pressure system over the great basin… Pumped copious amounts of monsoonal moisture into the area. In addition…a weak stationary front stretched along the Front Range foothills and Palmer Divide.  This resulted in a prolonged period of moderate to heavy rain across the Front Range foothills…Palmer Divide…urban corridor. By the 14th…storm totals ranged from 6 to 18 inches… Highest in the foothills of Boulder County. The headwaters then moved down the South Platte River and caused widespread flooding with record flood stages at several locations as it made its way downstream.  The record high flood stages resulted in widespread flooding along the South Platte River basin. The flood damage encompassed 4500 square miles of the Front Range…left 7 dead… Forced thousands to evacuate…and destroyed thousands of homes and farms. Record amounts of rainfall generated flash floods that tore up roads and lines of communication… Leaving many stranded. Nearly 19000 homes were damaged… And over 1500 destroyed. Colorado department of transportation estimated at least 30 state highway bridges were destroyed and an additional 20 seriously damaged. Preliminary assessments of the state`s infrastructure showed damage of $40 million to roads and $112 million to bridges. Repair costs for state and county roads ran into the hundreds of millions of dollars. Miles of freight and passenger rail lines were washed out or submerged… Including a section servicing Amtrak`s iconic California Zephyr. The town of Lyons was isolated by the flooding of St. Vrain creek…and several earth dams along the Front Range burst or were over-topped. Floodwaters swept through Estes Park; damaged hundreds of buildings and destroyed large sections of U.S. 34 from Loveland and U.S. 36 from Lyons to Boulder. U.S. 34 suffered the most damage… With 85 percent of its roadway and bridges destroyed. In Weld County…about nearly two thousand gas wells were damaged and had to be closed off as the floodwaters inundated entire communities. Sewage treatment plants and other utilities were knocked out in a number of towns. Governor Hickenlooper declared a disaster emergency on September 13th…in 11 counties across northeast Colorado including:  Adams…Arapahoe…Broomfield…Boulder…Denver…  Jefferson…Larimer…Logan…Morgan… Washington and Weld. By the 15th…federal emergency declarations covered those counties as well as Clear Creek County. Projected losses from the flooding statewide was nearly two billion dollars in property damage…according to Eqecat… A catastrophe modeling firm.  The damage was most severe in and around Lyons and Boulder.  More than 11 thousand people were evacuated…reportedly the largest since Hurricane Katrina. President Obama declared a state of emergency for Boulder and Larimer counties.  An additional 10 counties were added on the 16th and included: Adams… Arapahoe…Broomfield…Clear Creek…Denver…Jefferson…  Morgan…Logan… Washington and Weld counties. The president also declared a major disaster specifically for Boulder County.  There were six fatalities directly attributed to flash flooding. Two 19-yr old teenagers died on the 11th…after they were swept away by floodwaters after abandoning their car on Lindon Drive in Boulder. In Jamestown…a 72-yr old man was killed when the building he was in collapsed. An 80-yr old Lyons resident died in the early morning hours of the 12th…when his truck was swept into the St. Vrain River near his home. Later on the 12th…a 79-yr old Larimer County resident was killed when she was swept away while trying to climb to safety from her home in Cedar Point. A 61-yr old cedar point resident died when her home was swept down the Big Thompson River by the floodwaters. An 80-yr old Idaho Springs resident drowned in Clear Creek when the embankment he was standing on collapsed. In Boulder…some of the monthly records broken included: one-day all-time record: 9.08 inches which shattered the previous wettest day of 4.8 inches set on July 31… 1919; one-month record of 18.16 inches…which broke the previous all-time monthly record of 9.59 inches set in May of 1995; wettest September on record which broke the previous record of 5.5 inches set in September of 1940; one-year record of 34.15 inches broke the previous wettest year of 29.93 inches set in 1995. At Denver International Airport…the total precipitation for the month of September was 5.61 inches…which was 4.65 inches above the normal of 0.96 inches. This is the most precipitation ever recorded in Denver for the month of September. Daily precipitation records included 1.11 inches on the 12th and 2.01 inches on the 14th.

13

In 1899…west winds were sustained to 43 mph with gusts to 46 mph.

In 1928…northwest winds were sustained to 41 mph with gusts to 45 mph.

In 1937…an apparent dry microburst produced brief north winds sustained to 31 mph with gusts to 41 mph.  There was a trace of rain.

In 1982…torrential rains drenched both the foothills and plains from Denver north.  While the heaviest rain occurred north of Denver…just east of Denver 2 1/3 inches of rain fell in 5 hours along with hail that caused minor damage to a few airplanes.  Thunderstorm rainfall totaled 0.83 inch at Stapleton International Airport.

In 1993…an upper level system combined with a cold and moist upslope flow to bring the heaviest snowfall to metro Denver for so early in the season.  Snowfall from the storm totaled 5.4 inches at Stapleton International Airport; however…most of the snow melted as it fell leaving a maximum of one inch on the ground at any one time.  North winds gusted to 21 mph at Stapleton International Airport where a record low temperature of 33 degrees for the date was observed.

In 2002…Friday the 13th proved to be bad luck for several motorists when heavy thunderstorm rainfall caused flooding on I-25 in central Denver.  Water rose several feet under the Logan Street overpass…inundating several vehicles. Some motorists were rescued…while others simply waited atop their cars for the flood water to recede.  The highway had to be closed in both directions for about 3 hours.  The flooding was exacerbated by poor drainage due to the construction along the highway.  A 12-foot drainage pipe had not yet been installed beneath the underpass.  The deluge also flooded several businesses along Broadway.

In 2009…a severe thunderstorm produced large hail… Up to half dollar size in the foothills of Jefferson County…west of Denver.

14

In 1912…snow fell for most of the day…but melted as it fell. Precipitation from melted snow was 0.46 inch.  Some sleet was also observed.  Total precipitation was 0.61 inch.  North winds were sustained to 15 mph with gusts to 17 mph.

In 1934…a moderate dust storm blew into the city at 4:15 pm. North winds were sustained to 35 mph with gusts to 44 mph. By 5:25 pm the winds had decreased and the storm had ended. A trace of rain fell during the evening.

In 1976…a tornado touched down just west of I-25 between Arapahoe Road and Dry Creek Road…tearing the roof from a house.  Nearby…a high tension wire fell on a house causing damage…and lightning ripped a hole in the side of a house. Three tornadoes were observed just east of Stapleton International Airport and northeast of Buckley Field.  No damage was reported.  Dime to quarter size hail fell in northeast Denver with only 1/4 inch hail at Stapleton International Airport.  The Colorado State Patrol reported golf ball size hail 4 miles west of Franktown.  A funnel cloud was sighted 4 miles north of Franktown.

In 1983…a thunderstorm produced winds gusts as high as 56 mph across metro Denver along with thick blowing dust. Power was knocked out in many locations.  Thunderstorm winds gusting to 49 mph briefly reduced the visibility to 2 miles in blowing dust at Stapleton International Airport.

In 1996…a 54-year-old woman was struck by lightning near Franktown…as she was preparing an outdoor barbeque.  The woman was knocked unconscious…but received only minor injuries.  Thunderstorms over southern Jefferson County dumped heavy rain in the buffalo creek area.  Some minor roads were washed out by flash flooding…but no other damage was reported.  Hail ranging in size from 1/2 to 3/4 inch in diameter fell at the site of the former Stapleton International Airport.

In 2006…a microburst from a thunderstorm produced sustained winds to 40 mph with gusts to 53 mph at Denver International Airport.

Continue reading September 13 to September 19: This week in Denver weather history