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May 8 to May 11: This week in Denver weather history

This Week In Denver Weather History
May 8 to May 11: This week in Denver weather history

Think we are done with snow for the season? That may be the case this year but it isn’t always so. Looking back at this week in Denver history we do see snowfall has occurred along with more typical spring weather including heavy rains that led to flooding.

From the National Weather Service:

4-8

In 1969…heavy rains caused flooding on Boulder creek in Boulder…which resulted in one death on the 7th. Flooding also occurred on Bear Creek in Sheridan and on the South Platte River in Denver. Rain over most of the eastern foothills started late on the 4th and continued with only brief interruptions in many areas until the morning of the 8th. Very high rates of rainfall occurred on the 6th and 7th with the greatest intensities in a band along the foothills from about 25 miles southwest of Denver northward to Estes Park. Storm totals by both official and unofficial measurements exceeded 10 inches over much of this area and were over 12 inches in some localities. Heavy snow fell in the higher mountains and in the foothills later in the period. The saturation of the soil resulted in numerous rock and land slides…and the heavy run-off caused severe damage along many streams and flooding on the South Platte River. Many foothill communities were isolated as highways were blocked and communications disrupted. Roads were severely damaged over a wide area…and a large number of bridges washed out. Many roads were closed due to the danger from falling rocks. A building in Georgetown collapsed from the weight of heavy wet snow. In Boulder…a man drowned when caught by the flooding waters of Boulder Creek…and a patrolman was injured. Rainfall totaled 7.60 inches in Boulder with 9.34 inches recorded at the Public Service Company electric plant in Boulder Canyon. In Morrison…rainfall totaled 11.27 inches in 4 days. Heavy rainfall totaled 4.68 inches at Stapleton International Airport over 3 days from the 5th through the 7th. Rainfall of 3.14 inches was recorded in 24 hours on the 6th and 7th. Downstream flooding continued along the South Platte River until the 12th when the flood crest reached the Nebraska line.

7-8

In 1958…rainfall totaled 2.50 inches at Stapleton Airport.

8

In 1873…a very light rain fell until 5:00 am…when it turned into light snow and sleet and was accompanied by brisk northeast winds. The snow froze as it fell… Breaking the telegraph lines in many places. Precipitation totaled only 0.14 inch in the city.

In 1883…a severe rain and hailstorm struck the city. In 25 minutes the hail was 5 inches deep in the vicinity of the weather office in downtown Denver and reported as deep as 10 to 12 inches in other parts of the city. Gutters were blocked by the hail…and many cellars were flooded. Precipitation from the storm was 1.90 inches with the total for the day recorded at 2.02 inches. The size of the hail was not recorded.

In 1988…a wind gust to 68 mph was recorded at Echo Lake. Northwest winds gusted to 35 mph at Stapleton Airport.

In 1995…high winds of unknown strength blew a camper shell from the back of a pickup truck near Fort Lupton. North winds gusted to 49 mph at Denver International Airport.

In 1996…1 to 2 inch diameter hail was measured in Lochbuie northeast of Denver. Bean size hail fell in Brighton. The large hail fell from severe thunderstorms to the northeast of metro Denver.

In 2003…tornadoes touched down briefly near Brighton… Watkins…and Strasburg…but did no reported damage. Hail to 3/4 inch in diameter was measured near Hudson.

8-9

In 1957…intense heavy rain caused flash flooding on toll gate creek in Aurora where 3 people were killed in a car. Up to 4 inches of rain fell in 5 hours in the Toll Gate Creek basin. The rain also caused flash flooding on sand creek in Aurora and Denver. Rainfall totaled 3.29 inches at Stapleton Airport with most of the rain…2.34 inches… Occurring on the 9th.

8-10

In 1979…4.3 inches of snow fell at Stapleton International Airport where northwest winds gusted to 30 mph on the 8th. Most of the snowfall…2.3 inches…occurred on the 9th. High temperature of only 35 degrees on the 9th equaled the record low maximum for the date.

9

In 1875…a heavy windstorm swept across the city for most of the day. West-northwest winds averaged a sustained speed of 31 mph between 6:00 am and 3:00 pm. The peak wind was sustained to 45 mph at 9:50 am.

In 1918…post-frontal winds were sustained to 40 mph with gusts as high as 43 mph. Only a trace of rain fell.

In 1941…a tornado was noted at 2:20 pm to the northeast of downtown and was followed by another similar shaped cloud or dust roll estimated 3 miles behind. Thick dust followed with heavy gusts of wind. The temperature fell 15 degrees in 10 minutes following the twister. The mild tornado did little damage except to unprotected frame structures. Winds were sustained to 50 mph with the passing of the tornado at Stapleton Airport. It was visible to observers for 10 minutes and was lost from sight as it traveled east into huge rolls of dust. Hail and rain followed with a few hailstones as large as 1/2 inch in diameter downtown. No damage was reported from the hail. Thunderstorm winds sustained to 31 mph produced blowing dust downtown. Precipitation was only 0.07 inch.

In 1983…streams swollen by recent rain and snowmelt caused an earthen dam to collapse…washing out portions of State Highway 67 near Deckers in southern Douglas County.

In 1992…three boys…ages 11…12…and 16…were struck by lightning while taking cover under a large tree during a thunderstorm in Jefferson County…just 7 miles northwest of Denver. The three were seriously injured.

9-10

In 1889…heavy rainfall totaled 2.15 inches in downtown Denver. The cold rain was mixed with snow at times overnight. Temperatures on the 10th ranged from a high of 38 degrees to a low of 32 degrees with north winds sustained to 22 mph.

In 2003…a late spring snowstorm hammered the mountains… Eastern foothills…and urban corridor. The heaviest snowfall occurred north of interstate 70. The heavy wet snow caused damage to trees throughout metro Denver and downed power lines. About 40 thousand people along the urban corridor were without power. Storm total snowfall amounts included: 11.5 inches in Louisville… 8 inches in Boulder and Broomfield; 7 inches in Thornton…Broomfield…at Denver International Airport… And at the site of the former Stapleton International Airport; and 6 inches 4 miles east of Denver. Snowfall ranged from 4 to 9 inches across extreme southern weld County. In the foothills…15 inches of snow fell near Jamestown…9 inches at Rollinsville and Rawah…with 8 inches at Chief Hosa and atop Lookout Mountain. The snow was accompanied by thunder on the afternoon of the 9th at Denver International Airport where west winds gusted to 25 mph on the 9th and north winds gusted to 22 mph on the 10th.

10

In 1875…a windstorm sand-blasted the city from 10:00 am until midnight. Northwest winds sustained to 60 mph brought clouds of sand…which caused high damage to unfinished buildings.

In 1912…a vigorous cold front produced strong north winds and rain. North winds were sustained to 48 mph with gusts as high as 60 mph. Rainfall totaled 1.10 inch.

In 1935…no precipitation occurred…making this one of only two days without precipitation during the entire month. The other day was the 21st. Precipitation totaled 4.95 inches for the month.

In 1956…northwest winds gusted to 53 mph at Stapleton Airport where the visibility was briefly reduced to 1/2 mile in blowing dust.

In 1974…strong winds caused 30 thousand dollars in damage to a building under construction in Lakewood. Microburst winds gusted to 46 mph at Stapleton International Airport.

In 1988…lightning struck a house in Boulder…setting it afire. The house…valued at 170 thousand dollars…was a total loss.

In 1989…golf ball size hail fell over southeast Denver near the junction of I-25 and I-225. Hail to 3/4 inch in diameter fell over southeast Aurora. Only 3/8 inch hail fell at Stapleton International Airport.

In 1991…high winds up to 63 mph raked the eastern foothills. Winds estimated to 50 mph tore a roof from a home in Lafayette. A tower at Jefferson County stadium in west metro Denver was blown over by the high winds. No injuries were reported. Southeast winds gusting to 48 mph at Stapleton International Airport produced some blowing dust. The temperature climbed to a high of 86 degrees… Equaling the record maximum for the date.

In 2005…severe thunderstorms produced hail as large as 2 inches in diameter in and near Longmont.
10-11 in 1918…post-frontal snowfall totaled 4.7 inches in downtown Denver. Northwest winds gusted to 19 mph on the 10th.

In 1923…winds were strong and gusty on both days. Northwest winds were sustained to 40 mph with gusts to 44 mph on the 10th. North winds were sustained to 39 mph with gusts to 46 mph behind an apparent cold front on the 11th.

10-12

In 2011…a spring snowstorm brought heavy snow to the Front Range Foothills and Palmer Divide. Storm totals included: 18 inches…4 miles south-southeast of Pinecliffe; 16 inches in Coal Creek Canyon; 15 inches…4 miles west-southwest of Eldorado Springs; 13 inches at Gold Hill…12 inches…4 miles west-southwest of Conifer and 4 miles northwest of Elizabeth; 11.5 inches…6 miles southwest of Evergreen and 4 miles east-northeast of Nederland; 11 inches…3 miles east of Jamestown and 10.5 inches…3 miles east of Franktown and 3 miles south of Golden and 10 inches…10 miles north of Elizabeth. At Denver International Airport…1 inch of snowfall was observed.

11

In 1879…an apparent cold front during the afternoon produced sustained north winds as high as 60 mph and great clouds of blowing dust. The dust filled the air until the thunderstorm rain began…which produced 1.46 inches of rainfall. The rain ended during the evening.

In 1900…southwest winds were sustained to 40 mph with gusts to 46 mph.

In 1958…a microburst caused a brief wind gust to 55 mph at Stapleton Airport.

In 1963…south-southwest winds gusted to 48 mph at Stapleton Airport. Winds May have been stronger over west Denver where some buildings were damaged.

In 1998…large hail fell over south metro Denver. Hail as large as 1 1/4 inches in diameter was measured in Parker with 1 inch hail recorded in Littleton and 4 miles south of Lakewood in Jefferson County. Hail to 3/4 inch diameter was measured in Douglas County…11 miles west- northwest of Parker.

11-12

In 2014…A strong storm system moved from southwest Colorado and produced heavy snow in and near the Front Range Foothills and metro Denver.  The snow was heaviest in the foothills where up to 2 1/2 feet of snow was observed. In the foothills…storm totals included: 30 inches near Pinecliffe; 29 inches…8 miles northeast of Four Corners; 28 inches near Pingree Park; 27 inches near Allenspark; 20.5 inches near Idaho Springs; 19.5 inches at Gold Hill; 19 inches near Genesee; 18 inches near Blackhawk; 17 inches at Aspen Springs; 16.5 inches near Ward; 13.5 inches at Bergen Park; with 11 inches at Evergreen.  Along Urban Corridor and Palmer Divide…stormtotals included: 10.5 inches at Eldorado Springs; 10 inches at Ken Caryl; 9 inches at Superior; 8 inches near Morrison; 7.5 inches in Broomfield and Highlands Ranch; 7 inches in Denver…near Franktown…Golden…Lakewood and Highlands Ranch; 6 inches…5 miles northeast of Westminster…7 miles south of Lyons and near Parker; with 5.5 inches at Aurora. At Denver International Airport…1.1 inches of snowfall was observed…along with 0.9 inches of water.

12

In 1875…two forest fires on the eastern slope of the foothills were visible from the city.

In 1904…north winds were sustained to 40 mph with gusts to 48 mph.

In 1950…brilliant and complete primary and secondary rainbows arching across the sky were observed from Stapleton Airport.

In 1951…a wind gust to 51 mph was recorded at Stapleton Airport.

In 1984…winds gusted to 69 mph in Boulder. Northwest winds gusted to 47 mph at Stapleton International Airport.

In 1987…a small weak tornado touched down for about 2 minutes in southeast Denver. The twister hit a car dealership…blowing about a dozen windows out of cars and shattering four skylights on the building. Some tin roofing was blown off a patio a block and a half away. The tornado also downed a power pole. Damage at the dealership was estimated at 10 thousand dollars. A man was slightly injured by lightning in northwest Aurora.

In 1995…several funnel clouds were sighted near Parker. One of the funnels produced a short-lived debris cloud on the ground in an open field. No damage was reported.

12-13

In 1907…the temperature warmed to a high of 73 degrees on the 12th…before a cold front produced a thunderstorm… Northeast winds sustained to 40 mph…and rain changing to light snow overnight. Snowfall totaled only 2 inches…but the high temperature on the 13th was only 39 degrees.

In 1961…a storm that covered metro Denver with rain and snow started as thunderstorms on the evening of the 12th. Hail to 1 1/2 inches in diameter was reported 10 miles northwest of Stapleton Airport. Rain continued overnight and changed to snow on the 13th. Snowfall totaled 6.4 inches and precipitation (rain and melted snow) 1.96 inches at Stapleton Airport where north winds gusted to 39 mph. The rain and heavy wet snow caused icing damage to utility lines. Heavy snow occurred in the foothills.

In 1982…a major storm dumped 1.50 to 3.50 inches of rain across northeast Colorado and deposited prodigious amounts of snow in the foothills. Coal Creek Canyon southwest of Boulder was buried under 46 inches of snow with 39 inches at Nederland. The heavy wet snow downed many power lines in the foothills. In Thornton…the roof of a school was damaged by water from the heavy rain. At Stapleton International Airport…1.49 inches of rain were measured over the two day period. The heavy rain ended a severe and prolonged drought.

In 2004…a winter storm produced heavy snow in excess of a foot in the foothills above 6 thousand feet while heavy rain fell across the city. The heaviest snow occurred in the high country of Boulder County. Storm total snowfall was 14.5 inches near Jamestown. Rainfall totaled 0.81 inch at Denver International Airport with 0.94 inch recorded at Denver Stapleton. A trace of snow was recorded at both locations. East winds gusted to 24 mph at Denver International Airport on the 12th.

13

In 1905…a thunderstorm produced hail during the late afternoon. Precipitation totaled 0.57 inch.

13-14

In 1912…heavy snowfall totaled 12.4 inches over the city. Most of the snow…9.9 inches…fell on the 13th…which was the greatest 24 hour snowfall in May at the time. This was the last snowfall of the season. The low temperature dipped to 27 degrees on the morning of the 14th.

In 1989…a spring storm brought heavy rain and snow to the foothills. Metro Denver was soaked with 1 to 2 inches of rain. Rainfall totaled 1.26 inches at Stapleton International Airport. In the foothills…Echo Lake received 20 inches of snow. A 30-ton Boulder slid onto I-70 east of the Eisenhower Tunnel…closing the freeway for 2 hours.

14

In 1910…a thunderstorm produced strong winds during the afternoon. Northwest winds were sustained to 42 mph.

In 1913…light moist snow and light hail fell during short intervals…although no thunder was heard. The trace of snowfall was the only snow of the month. Precipitation… Mostly rain…totaled 0.44 inch.

In 1984…a pilot reported a tornado 16 miles east of Stapleton International Airport. No damage was reported. A thunderstorm produced a 58 mph wind gust in Brighton. Thunderstorm winds gusted to 48 mph at Stapleton International Airport.

In 1989…lightning struck a home in Evergreen…setting it afire.

In 1992…strong thunderstorm winds of unknown velocity… Knocked over and damaged the infield tote board at Arapahoe park racetrack just southeast of Aurora. Damage was estimated at 200 thousand dollars. No injuries were reported. Lightning started two house fires…causing 35 hundred dollars in damage in Adams County just 9 miles north-northwest of Denver.

In 1994…a sudden wind gust…estimated at 40 mph…blew a portion of the roof off a shopping center in Lafayette. The roof also damaged two parked cars in an adjacent lot.

In 2001…a construction worker in Castle Rock received minor injuries when lightning struck close-by.

In 2002…a microburst wind gust to 53 mph was recorded at Denver International Airport.

In 2007…severe thunderstorms producing large hail…very heavy rain…and tornadoes impacted the urban corridor and adjacent plains. Heavy rain associated with a severe thunderstorm caused flooding along a small tributary draining into the South Platte River. The incident took place at 13th and Decatur St….near Invesco Field. The floodwaters inundated the bike trail adjacent to the creek. A woman with her child sought refuge under a bridge and became trapped by the high water. The woman slipped and the stroller containing the child was swept into the swift current. The child drowned. Rainfall totaled 0.42 inches at Denver International Airport. Elsewhere…golfball hail was reported near Hudson. Hail…up to one inch in diameter…was observed in Boulder and Lyons. Thunderstorm wind gusts estimated to 70 mph were reported near Buckley Air Force Base…with a peak wind gust to 37 mph observed at Denver International Airport. A small tornado touched down near Ft. Lupton but did no damage.

14-15

In 1977…high winds up to 100 mph felled hundreds of trees in Gilpin County and caused extensive damage to telephone and power lines. Lumber and steel tanks were blown around in Boulder canyon. West winds gusted to 46 mph at Stapleton International Airport on the 15th.

14-18

In 1996…a period of unusually warm weather resulted in 4 record maximum temperatures in 5 days. The record high temperatures were 87 degrees on the 14th…89 degrees on the 15th…and 93 degrees on both the 16th and 18th. The temperature climbed to only 81 degrees on the 17th which was not a record.

Thornton’s May weather preview: Anything from snow to severe storms

Thornton, Colorado May 2013 weather preview.
Thornton, Colorado May 2016 weather preview.

Colorado’s famously highly variable weather seems to showcase itself during the month of May when a variety of weather conditions can be seen.

Winter-like temperatures and snow are possible as are mid-summer like temperatures or the more typical spring severe weather.

As the month starts out in 2016 we see snow but then warmer, milder weather is expected to arrive for the balance of the first week of the month.  Long range forecasts lean toward overall cooler and wetter than normal conditions.

However the month can bring extremes.  Snow is not entirely uncommon during the month, oftentimes causing damage to newly bloomed trees.  More common however is severe weather, particularly in the latter half of the month.  Thunderstorms become more frequent and their associated hazards – lightning, wind, hail and tornadoes – are usual visitors.

For a complete look at what lies ahead for the month of May, check out our full preview here.

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

This Week In Denver Weather History
May 1 to May 7: This week in Denver weather history

May can bring a variety of conditions from snow and cold to severe thunderstorms and flooding rains. Looking back at this week in Denver weather history we see where all of those events have made an appearance in our past.

From the National Weather Service:

29-2

In 1954…a major storm dumped 10.1 inches of snowfall at Stapleton Airport. Most of the snow…7.5 inches…fell on the 29th and 30th. The maximum snow depth on the ground was 5 inches on the 30th due to melting. No strong winds accompanied the storm.

30-1

In 1980…to the west of Denver…heavy rain changing to snow buried the foothills above 7 thousand feet in 4 to 8 inches of snow. Precipitation in the foothills ranged from 1 to 3 inches…which caused some local flooding. Rain fell at lower elevations. Rainfall at Stapleton International Airport totaled 1.05 inches from the storm.

1

In 1902…northwest winds were sustained to 68 mph with gusts as high as 74 mph in the city during the early morning. The apparent very strong Chinook winds warmed the temperature to a high of 78 degrees.

In 1912…south winds were sustained to 42 mph with gusts as high as 58 mph. South to southwest winds were strong all afternoon.

In 1935…a moderate duststorm blew into the city at around 2:00 pm on northwest winds sustained to 17 mph with gusts to 19 mph. Later in the afternoon…the dust receded to the east in advance of a rainstorm from the west.

In 1988…very strong winds behind a vigorous cold front produced a blinding dust storm that closed I-70 east of Denver. Northeast winds over metro Denver peaked to 45 mph at Stapleton International Airport…but only kicked up some blowing dust. The temperature plunged from a high of 76 degrees at midday to 36 degrees at midnight as light rain changed to light snow.

In 1991…3/4 inch diameter hail fell at Standley Lake in northwest metro Denver.

In 1999…heavy snow developed in the foothills above 7 thousand feet elevation. Snow totals included: 10 inches at Rollinsville…7 inches near conifer…and 6 inches atop Crow Hill. Rain fell across metro Denver.

1-2

In 1903…post-frontal rain changed to light snow overnight… But totaled only 2.0 inches. This was the last snow of the season. Northeast winds were sustained to 45 mph with gusts to 48 mph on the 1st.

1-5

In 1898…snowfall totaled 15.5 inches in downtown Denver. Most of the snow…6.2 inches…fell on the 3rd. Most of the snow melted as it fell. The greatest snow depth on the ground was only 2.5 inches on the 3rd at 8:00 pm. This was the only snowfall during the month. Northeast winds were sustained to 22 mph on the 1st.

2

In 1874…strong winds upset two railroad passenger coaches near Georgetown. The baggage was retrieved and placed in a heavy…large wagon. The passengers then seated themselves on top of the baggage. Another strong gust of wind upset the wagon. The driver’s shoulder was dislocated…and a passenger’s leg was badly injured. In Denver…northwest winds increased and blew in gusts and heavy winds were observed on the ridge tops. On the Kansas Pacific R.R. east of Denver…the wind was so strong that it blew the train back several lengths…which caused the train to be about 7 hours late arriving in the city.

In 1901…south winds were sustained to 50 mph with gusts to 60 mph from an apparent thunderstorm with hail.

In 1944…snowfall of 8.3 inches was accompanied by a thunderstorm. This was the last snowfall of the season and the only snow of the month. Northwest winds were sustained to 25 mph.

In 1955…southwest winds at speeds of 37 mph with gusts as high as 58 mph caused some blowing dust at Stapleton Airport.

In 1983…1 inch diameter hail fell a few miles south of Bennett.

In 1984…3/4 inch diameter hail fell in Northglenn.

In 1988…I-70 east of Denver was closed for the second straight day…this time due to snow and blowing snow producing up to 2 foot drifts. While only 2 to 4 inches of snow fell across metro Denver…Strasburg…just east of Denver…received a foot of snow. North winds peaked to 51 mph at Stapleton International Airport where snowfall totaled only 1.3 inches.

In 1995…lightning struck a house in Westminster sparking an attic fire.

2-3

In 1979…heavy rain changed to snow on the 2nd. Snowfall totaled 3.9 inches at Stapleton International Airport… Where northwest winds gusted to 26 mph. The greatest depth of snow on the ground was only 1 inch at midday on the 2nd due to melting. Total precipitation for the 2 days was 1.65 inches.

2-4

In 1987…a slow moving storm brought rain…wind…and snow to metro Denver. Rainfall totaled 1.04 inches at Stapleton International Airport where north winds gusted to 48 mph on the 3rd. The foothills received 5 to 10 inches of snow.

2-5

In 2001…a very slow moving pacific storm system became parked near the four corners region…which allowed heavy snow to develop above 6500 feet in the foothills with a mix of rain and snow over lower elevations of metro Denver. Snowfall totals included: 21 inches atop Crow Hill and at Idaho Springs; 19 inches near Blackhawk; and 18 inches in Coal Creek Canyon…Genesee…and 11 miles southwest of Morrison. Snowfall totaled 6.2 inches at the site of the former Stapleton International Airport. Precipitation (rain and melted snow) totaled 2.09 inches at Denver International Airport where north winds gusted to 30 mph on the 2nd.

3

In 1898…heavy snowfall of 6.2 inches fell over downtown Denver. Most of the snow melted as it fell. The greatest snow depth on the ground was 2.5 inches during the evening.

In 1907…the all-time lowest recorded temperature in the month of May…19 degrees…occurred.

In 1925…an apparent microburst produced sustained northeast winds to 44 mph with gusts to 52 mph. Rainfall was only 0.01 inch in downtown Denver.

In 1981…lightning struck 9 golfers at the south suburban golf course. None were injured seriously.

In 1983…hail 1 1/2 inches in diameter fell at Green Mountain west of Lakewood…with 3/4 inch stones reported in Lakewood.

In 1986…a thunderstorm wind gust to 51 mph was recorded at Stapleton International Airport.

3-5

In 1908…rain changed to snow on the evening of the 3rd and continued through the early evening of the 5th. Snowfall totaled 10.0 inches over downtown Denver. This was the last measurable snow of the season. Precipitation totaled 1.51 inches. North winds were sustained to 23 mph on the 3rd…33 mph on the 4th…and 21 mph on the 5th. Three temperature records were set. High temperatures of 30 degrees on the 4th and 38 degrees on the 5th were record low maximum temperatures for the dates. The reading on the 4th was also the all-time record low maximum for the month of May.

In 2007…a slow moving pacific storm system…from the desert southwest…brought a period of unsettled weather to the region. During the 3-day period…locally heavy snow was reported over parts of the Front Range foothills. Storm totals included: 15 inches near Conifer…14.5 inches west of Jamestown…13.5 inches; 6 miles southwest of Evergreen…and 12.5 inches at Pine Junction. Severe thunderstorms…producing large hail…up to one inch in diameter were observed in the vicinity of Boulder and Hudson. Lightning struck a residence in Jefferson County. The roof was hit…causing the attic to catch fire. At Denver International Airport…lightning struck a United Airlines jet as it was pushing away from the gate. The passengers were taken off the jet and put on another plane.

4

In 1893…northwest winds were sustained to 42 mph.

In 1971…a funnel cloud was sighted 10 miles southwest of Boulder. Hail stones to 1 inch in diameter fell in southeast Denver…but caused only minor damage.

In 2006…a severe thunderstorm produced hail to 1.00 inch in diameter in Aurora near Cheery Creek Reservoir.

In 2010…high winds downed trees and power lines across parts of the Front Range foothills and urban corridor. Downed power lines sparked a 12-acre wildfire near Conifer. In Boulder…Longmont and Louisville…the wind damaged roofs and broke windows and skylights. Peak wind gusts included: 75 mph in northwest Longmont…71 mph at the national wind technology center and 4 miles south-southwest of Superior…61 mph at Broomfield and 56 mph in Erie. At Denver International Airport…a peak wind gust to 46 mph was observed.

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

May 31 to June 6: This week in Denver weather history

This Week In Denver Weather History
May 31 to June 6: This week in Denver weather history

An extremely eventful week in Denver weather history.  Most notably for longtime Thornton and Northglenn residents is the 28 year anniversary of the infamous Thornton Tornado which struck on June 3, 1981.

From the National Weather Service:

26-31

In 1995…a cool period with light morning showers and moderate to heavy afternoon showers and thunderstorms pushed rivers already swollen from mountain snow melt over their banks causing minor flooding.  Streams and rivers such as the South Platte and Boulder Creek flooded meadowlands…bike paths…roads near streams…and other low lying areas.  No significant property damage was reported and crop damage was unknown.  Rainfall totaled 1.79 inches at the site of the former Stapleton International Airport and only 1.51 inches at Denver International Airport.

29-1

In 1894…heavy rain combined with snowmelt runoff caused widespread flooding over the South Platte River basin. Rainfall was heaviest in the foothills where 5 to 8 inches were measured over the 4 days.  Heavy rainfall west of Boulder flooded mining towns and damaged mining properties.  In the canyons above Boulder…railroads and roads were washed out along with many bridges.  The floodwaters spread into central Boulder and covered a wide area from University Hill north to near Mapleton Hill to a maximum depth of 8 feet.  Many houses were swept away…and every bridge in Boulder was destroyed. A few people…trapped in their homes by the floodwaters… Had to be rescued.  However…the gradual rise of the flood waters resulted in only one death.  Boulder Creek spread to a width of nearly one mile in the pasture land to the east of Boulder.  Extensive flooding on Left Hand Creek north of Boulder washed away railroad and wagon bridges.  The heavy cloudbursts caused flooding on Bear Creek…which washed away bridges…railroad tracks…and structures and destroyed the canyon roadway.  Morrison sustained the heaviest flood damage on bear creek.  In Denver…rainfall totaled only 1.50 inches on the 30th and 31st…but the heavy rainfall on upstream tributaries of the South Platte River caused the river to rise as much as 10 feet above the low water mark in the city…which caused some flooding of pasture land downstream to a depth of 6 feet near Brighton.

30-31

In 1935…heavy thunderstorm rains overnight caused flash flooding east of the city on both Kiowa and Bijou Creeks… Resulting in a total of 9 deaths.  Most of the damage was on Kiowa Creek where there were more structures.  The water rose rapidly during the storm…ripping houses and stores from their foundations and sweeping them downstream. Precipitation in Denver totaled only 0.01 inch.  Hail fell in the city for a short time.  The hail was very small and caused no damage.

In 1983…a late storm of rain and snow hit the Front Range. Over an inch of rain fell at some spots…and above 7 thousand feet…1 to 5 inches of snow whitened the ground. Some snow flakes even fell in the western suburbs of metro Denver on the night of the 30th.

In 2002…unseasonably warm weather at the end of the month resulted in 3 temperature records.  High temperature of 91 degrees on the 30th equaled the record maximum for the date.  Low temperature of 61 degrees on the 31st was a record high minimum for the date.  High temperature of 93 degrees on the 31st was a record maximum for the date.

31

In 1917…rainfall totaled 0.55 inch and was mixed briefly with snow around midday.  Only a trace of snow fell. Cold temperatures during the day resulted in a high of 44 degrees and a low of 35 degrees.  The month closed as the coldest May on record with a mean temperature of only 48.7 degrees…about 8 degrees below normal.  The cold temperatures during the month had a marked effect on shade trees and shrubs in the city.  Elms were just starting to leaf.  Leaves on cottonwoods and maples were only half formed.  Lilacs were just blooming…and snowball clusters would not bloom for days.

In 1959…the public reported a tornado briefly touching the ground 10 miles south of Stapleton Airport.  No damage was reported.

In 1984…a thunderstorm microburst produced a wind gust to 67 mph…7 miles east of Boulder.

In 1991…hail to golf ball size pummeled southern and southeastern sections of metro Denver and continued on east to Watkins.  Several houses and cars were damaged.  Later… Thunderstorms dumped heavy rain across the city of Denver… Causing street flooding in an area just south of downtown and just northwest of downtown.  Water was up to 10 inches deep over northwest Denver.  A brief tornado touched down in Castle Rock where 3/4 inch diameter hail also fell.

In 1993…thunderstorms dropped dime size hail in Commerce City.

In 1994…lightning struck an apartment in Louisville and damaged electronic equipment…including a computer.

In 2006…a severe thunderstorm produced 1 inch diameter hail near Boulder.

1

In 1875…a windstorm during the late afternoon and early evening produced sustained winds to 50 mph.

In 1898…south winds were sustained to 41 mph with gusts to 46 mph.

In 1917…a trace of unmelted snow fell in downtown Denver. Precipitation for the day totaled 0.08 inch…half of which was estimated to be from melted snow.

In 1919…snowfall of 0.4 inch was measured in downtown Denver.  This was the greatest calendar day and 24-hour snowfall ever recorded during the month of June. Precipitation (rain and melted snow) totaled 0.15 inch. Two temperature records were set.  The low temperature of 32 degrees was a record minimum for the date.  The high temperature of only 40 degrees was a record low maximum for the date and the month.  North winds were sustained to 36 mph with gusts to 40 mph.

In 1951…a trace of snow fell at Stapleton Airport.

In 1961…hail as large as 1 1/2 inches in diameter fell in west Denver with hail to 1 1/4 inches reported in derby.

In 1965…a man struck by lightning in southeast Denver died shortly after being admitted to a hospital.  Lightning damaged power lines in east and southeast Denver.

In 1980…strong thunderstorm winds blew in the windows of a mobile home in Northglenn.

In 1990…a thunderstorm produced wind gusts to 63 mph in Boulder.  A small tornado touched down in a farmer’s field between the towns of Louisville and Lafayette.  Another tornado was spotted in an open field 3 miles west of Brighton.  A funnel cloud was sighted near Hudson. A microburst wind gust to 55 mph was recorded at Stapleton International Airport.  No damage was reported from any of these events.

In 1991…severe thunderstorms producing large hail…damaging winds…funnel clouds…and heavy rain were widespread across metro Denver.  Funnel clouds were reported in Lakewood… Boulder…Arvada…and just east of the rocky mountain arsenal.  Hail up to golf ball size fell in Lakewood…just west of Sedalia…in Littleton…Arvada…Englewood…and the city of Denver.  A mobile home park in Jefferson County reported hail to 3 feet deep.  Up to 1.00 inch of rain fell in 45 minutes near Boulder…causing Boulder Creek to flow out of its banks.  Rock and mud slides forced the closure of many roads in Boulder County.  Later in the afternoon thunderstorms produced rainfall amounts of 2 to 3 inches over a couple of hours.  Clear Creek in Golden spilled over onto U.S. Highway 6.  Heavy rains washed away part of a bridge near Erie.  Water was up to 18 inches deep in Westminster.  Wind gusts to 58 mph were reported at Stapleton International Airport where 1/4 inch hail fell… And heavy thunderstorm rainfall totaled 0.82 inches…briefly reducing the visibility to 1 1/4 miles.  Estimates of total damage from these storms would exceed 7 million dollars.

In 1994…hail up to 1 inch in diameter fell over south Denver and Littleton.

In 1997…two short lived-tornadoes formed near Bennett…but did no reported damage.

In 2002…strong winds from the outflow of dissipating showers developed to the east of Denver.  Near Strasburg…a spotter recorded a wind gust to 58 mph.

Continue reading May 31 to June 6: This week in Denver weather history

May 2015 weather recap: A very wet, cool month for Thornton

The first quarter of the year started out dry but April started to signal a turn toward wetter conditions and the month of May certainly followed through on that.  Not only was it a very wet month, it was also much cooler than normal.

A seemingly endless series of disturbances moved through the state almost from the first day through the last day of May 2015.  We started out dry but the third of the month began the wet period with five straight days of precipitation.  That was capped off by a decent shot of snowfall on the 10th of the month.

After that we did dry out for at least a few days before the wet weather returned on the 15th, albeit with lesser amounts of precipitation overall.  By the time the month was over, 18 of the 31 days had seen measureable precipitation in Thornton.

Temperatures were quite cool for the month with the average in Thornton coming in at 52.2 degrees.  This was nearly five degrees below Denver’s May average of 57.1 degrees.  As measured at Denver International Airport, the Mile High City officially saw an overage of 53.0 degrees.

Thornton’s mercury readings ranged from a high of 87.3 degrees on the 31st down to a low of 27.8 degrees on the morning of the 10th.  Denver saw its warmest reading of 85 degrees on the 31st also and its coldest reading of 27 degrees occurred on the 9th and 10th.

In terms of precipitation, the numbers help to showcase just how wet of a month it was.  Here in Thornton we recorded 6.40 inches of liquid precipitation, far above the long term Denver average for May of 2.12 inches.  Officially, Denver also saw above normal precipitation although not by near as much as they recorded 3.76 inches.

That reading was not enough to push May 2015 into the books as one of the top 10 wettest Mays.  However, the airport’s outlying location as compared to historical measurement sites is probably the only reason why.  As Thornton’s measurement and those of other station’s shows, we were far wetter than what DIA saw.

Snowfall in May is not unusual and Thornton saw 5.1 inches from one storm on the 9th and 10th.  Out at the airport 4.0 inches was recorded.  Both were a good bit above the May average of 1.1 inches.

Click here to view Thornton’s May 2015 climate report.

Thornton, Colorado's May 2015 temperature summary. (ThorntonWeather.com)
Thornton, Colorado’s May 2015 temperature summary. (ThorntonWeather.com)
Thornton, Colorado's May 2015 precipitation summary. (ThorntonWeather.com)
Thornton, Colorado’s May 2015 precipitation summary. (ThorntonWeather.com)
CLIMATE REPORT
NATIONAL WEATHER SERVICE BOULDER, CO
645 AM MDT MON JUN 1 2015

................................... 

...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF MAY 2015... 

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2015

WEATHER         OBSERVED          NORMAL  DEPART  LAST YEAR`S
                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
                                          NORMAL
................................................................ 
TEMPERATURE (F)
RECORD
 HIGH              95   05/26/1942
 LOW               19   05/02/2013
                        05/03/1907
HIGHEST            85   05/31                         87  05/28
                                                          05/29
LOWEST             27   05/10                         30  05/12
                        05/09
AVG. MAXIMUM     63.3              71.5    -8.2     70.6
AVG. MINIMUM     42.7              42.7     0.0     44.5
MEAN             53.0              57.1    -4.1     57.5
DAYS MAX >= 90      0               0.8    -0.8        0
DAYS MAX <= 32      0               0.0     0.0        0
DAYS MIN <= 32      3               1.9     1.1        4
DAYS MIN <= 0       0               0.0     0.0        0 
PRECIPITATION (INCHES) 
RECORD
  MAXIMUM         8.57   1876
  MINIMUM         0.06   1974
TOTALS           3.76              2.12    1.64     3.51 
DAILY AVG.       0.12              0.07    0.05     0.11 
DAYS >= .01        19               9.4     9.6       13
DAYS >= .10        10               4.8     5.2        6
DAYS >= .50         2               1.2     0.8        3
DAYS >= 1.00        1               0.2     0.8        1
GREATEST
 24 HR. TOTAL    1.18   05/08 TO 05/09           05/20 TO 05/21

SNOWFALL (INCHES)
TOTAL             4.0               1.1
RECORD MAY       15.5                                      1898

DEGREE_DAYS
HEATING TOTAL     367               265     102      244
 SINCE 7/1       5572              5996    -424     5974
COOLING TOTAL       4                21     -17       21
 SINCE 1/1          4                22     -18       21

FREEZE DATES
RECORD
 EARLIEST     09/08/1962
 LATEST       06/08/2007
NORMAL
 EARLIEST                         10/07
 LATEST                           05/05
.................................................. 

WIND (MPH)
AVERAGE WIND SPEED              9.3
RESULTANT WIND SPEED/DIRECTION   2/106
HIGHEST WIND SPEED/DIRECTION    45/280    DATE  05/02
HIGHEST GUST SPEED/DIRECTION    54/280    DATE  05/02

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.80
NUMBER OF DAYS FAIR            0
NUMBER OF DAYS PC             15
NUMBER OF DAYS CLOUDY         16

AVERAGE RH (PERCENT)     70

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              0     MIXED PRECIP               0
HEAVY RAIN                2     RAIN                       9
LIGHT RAIN               23     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                1     SNOW                       1
LIGHT SNOW                2     SLEET                      0
FOG                      14     FOG W/VIS <= 1/4 MILE      7
HAZE                      3

-  INDICATES NEGATIVE NUMBERS.
R  INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T  INDICATES TRACE AMOUNT.

May 2015 top shots: Monthly photo slideshow

Lightning streaks across the skies on May 6, 2015. (David Canfield)
Lightning streaks across the skies on May 6, 2015. (David Canfield)

Colorado’s famously highly variable weather seems to showcase itself during the month of May when a variety of weather conditions can be seen.  This provides a prime opportunity for photos of everything weather to flora to fauna.

The month of May can bring extremes.  Snow is not entirely uncommon during the month but more common is severe weather, particularly in the latter half of the month.  Thunderstorms become more frequent and their associated hazards – lightning, wind, hail and tornadoes – are usual visitors.  Providing additional subjects for pictures are the emerging spring flowers and our abundant wildlife.

  • Slideshow updated May 31, 2015. To learn more about how to send your photo to us for inclusion in the slideshow, see below the slideshow.

Showcasing images captured by ThorntonWeather.com readers as well as some of our own, our monthly slideshow covers the entire gamut of weather-related imagery.

Sunsets, sunrises, wildlife and of course every type of weather condition are vividly depicted in images captured from yours and our cameras.

[flickr_set id=”72157652075811140″]

What is missing in the slideshow above?  Your photo!

Our monthly photo slideshow is going to feature images that we have taken but more importantly images that you have captured.  The photos can be of anything even remotely weather-related.

Landscapes, current conditions, wildlife, pets, kids.  Whimsical, newsy, artsy.  Taken at the zoo, some other area attraction, a local park, a national park or your backyard.  You name it, we want to see and share it!

Images can be taken in Thornton, Denver or anywhere across the extraordinary Centennial State.  We’ll even take some from out of state if we can tie it to Colorado somehow.

We’ll keep the criteria very open to interpretation with just about any image eligible to be shown in our slideshows.

What do you win for having your image in our slideshow?  We are just a ‘mom and pop’ outfit and make no money from our site so we really don’t have the means to provide prizes.  However you will have our undying gratitude and the satisfaction that your images are shared on the most popular website in Thornton.

To share you images with us and get them included in the slideshow just email them to us or share them with ThorntonWeather.com on any of the various social media outlets.  Links are provided below.

So come on, get those camera’s rolling!

May 24 to May 30: This week in Denver weather history

This Week In Denver Weather History
May 24 to May 30: This week in Denver weather history

Severe weather in spades is evident on our look back at Denver weather history this week. Notable is an F1 tornado in 1990 that moved through the Northglenn and Thornton area that damaged buildings, cars and trees.

From the National Weather Service:

20-27

In 2002…lightning sparked a wildfire near Deckers. Extremely dry conditions and very strong winds the following day allowed the fire…known as the Schoonover…to consume 3850 acres before it could be contained. Thirteen structures were destroyed…including 4 homes…resulting in 2.2 million dollars in damage.

23-24

In 2002…a pacific storm system brought much needed snow to the mountains and foothills with a mix of rain and snow on the plains. The most snow fell from central Jefferson County northward. Snow totals included: 13 inches in Coal Creek Canyon…11 inches near Evergreen and atop Gold Hill… 10 inches near Blackhawk and Conifer and atop Crow Hill… 9 inches near Rollinsville…and 8 inches near Genesee and Golden. Rain was mixed with snow across the city. Precipitation totaled 0.61 inch at Denver International Airport. Snowfall was less than an inch at the site of the former Stapleton International Airport. The storm brought unseasonably cold air to metro Denver. Three temperature records were set. Low temperature of 31 degrees on the 23rd was a record minimum for the date…as was the low of 32 degrees on the 24th. The high temperature of only 48 degrees equaled the record low maximum for the date.

24

In 1953…a microburst caused a brief wind gust to 55 mph at Stapleton Airport.

In 1957…walnut size hail…1 1/2 inches in diameter…fell in east Denver. Only 1/4 inch hail was measured at Stapleton Airport.

In 1958…rainfall totaled 1 to 2 inches across metro Denver. Rainfall was only 0.37 inches at Stapleton Airport.

In 1974…a tornado was observed briefly near Watkins. No damage was reported.

In 1980…strong gusty winds of at least 60 mph damaged buildings in parts of Denver. Several buildings were unroofed in Sheridan. The flying debris damaged other structures. Strong microburst winds gusted to 52 mph at Stapleton International Airport.

In 1991…a tornado touched down briefly in open country near Bennett. No damage was reported.

In 1994…weather spotters reported 2 funnel clouds over Aurora and a short-lived waterspout on Cheery Creek Reservoir.

In 1997…hail to 1 inch in diameter fell in Broomfield with 3/4 inch hail measured in Boulder.

In 1998…a tornado struck a wooden hangar at the Aurora airpark. The hangar collapsed…damaging a car and a single engine plane parked inside. An adjacent steel hangar sustained only minor damage. The tornado moved northeast…hopped I-70…and touched down again in an open field. Earlier…a weak tornado touched down briefly in an open field 10 miles southeast of Buckley Field.

In 2003…severe thunderstorms produced large hail over northern and southern metro Denver. Hail as large as 2 3/4 inches in diameter was measured 10 miles northwest of Hudson and to 2 inches in diameter 10 miles northeast of Fort Lupton. One inch diameter hail fell in Fort Lupton. Hail to 1 inch in diameter fell near Parker and to 3/4 inch near Franktown.

In 2004…severe thunderstorms moved across northwest and north metro Denver. Hail as large as 1 inch in diameter fell in Broomfield and Thornton with 3/4 inch hail measured near Arvada and Hudson and in the city of Denver.

In 2005…severe thunderstorms produced hail as large as 1 inch in diameter in Arvada and the city of Denver.

In 2014…a severe thunderstorm in Lakewood produced hail… Up to 1 inch in diameter

24-26

In 1996…a late spring snowstorm dumped 4 to 10 inches of snow over the Front Range foothills. Conifer picked up 10 inches of new snow; aspen springs…9 inches; and central city…8 inches. The sticky…heavy snow clung to power lines and pulled tree branches down…causing power outages to about 1200 homes in the conifer area. It took up to 6 hours to restore power to some residences. Lightning struck a telephone data cabinet in conifer on the 25th…which knocked out phone service to about 1500 customers. Widespread rain fell across metro Denver… Where rainfall totaled 2.07 inches at the site of the former Stapleton International Airport and 1.66 inches at Denver International Airport where north winds gusted to 24 mph on the 26th.

In 2010…high winds preceding a cold front… Swept across the Front Range foothills and urban corridor. In Aurora… The wind damaged the roof of Rangeview High School. In Conifer and Denver…the wind downed trees and power lines and caused several brief outages. The downed power lines also caused several cars to catch fire in the vicinity of 1590 Cook St. in Denver. Peak wind gusts included: 82 mph at Highlands Ranch…67 mph… 4 miles east of Franktown and Longmont; 65 mph in Boulder…64 mph in Centennial and Denver International Airport…62 mph near Parker and 60 mph in Arvada.

25

In 1877…lightning killed one person in west Denver and struck several houses. The bolt struck the house of the “home laundry” stunning the occupants and killing a lady who was holding one of her grand children in her arms. The child escaped unhurt. The lightning also struck the top of a tree in front of the house and partially peeled the bark off the tree. Lightning struck a church in the Evans addition and another tree in east Denver. Lightning struck the switch room at the telegraph office where the operator saw small balls of lightning pass across the room to the stove. The thunderstorm pelted the city with only pea size hail. Precipitation from the storm totaled 0.40 inch in downtown Denver.

In 1880…light rain all afternoon totaled only 0.24 inch in the city…but was valuable to stockmen and farmers due to the very dry…parched weather conditions on the plains.

In 1965…a tornado was sighted by a pilot 30 miles south southeast of Denver. No damage was reported. Another pilot reported 3/4 inch hail 30 miles east of Denver. The state patrol reported that a man was killed when a fierce gust of wind swept him from the back of a pick-up truck in northwest Douglas County. The man was holding a mattress in the bed of the truck.

In 1974…a microburst wind gust to 53 mph was recorded at Stapleton International Airport. A pilot reported a tornado 20 miles east of Denver.

In 1976…lightning struck a home in Boulder…shattering 2 large trees and damaging a television set.

In 1997…hail as large as 1 3/4 inches in diameter fell near Watkins. Hail to 3/4 inch in diameter fell in Broomfield and near Lockbuie.

In 2000…3/4 inch diameter hail fell at Cheery Creek Reservoir in Aurora. Thunderstorm winds gusted to 51 mph at Denver International Airport where small hail fell.

In 2006…a severe thunderstorm produced an estimated wind gust to 70 mph in Hudson. The strong winds damaged the roof of a home. A thunderstorm produced southwest wind gusts to 54 mph at Denver International Airport.

25-26

In 1950…a major storm dumped 10.0 inches of snowfall downtown and 10.7 inches at Stapleton Airport where northwest winds gusted to 30 mph on the 25th. The storm caused extensive damage to utility wires and trees which were in full leaf. A daily record minimum temperature of 31 degrees occurred on the 25th. This was the coldest temperature on this date in 79 years and for so late in the season.

In 1989…a late season snow storm dropped snow as low as 6 thousand feet along the Front Range. Most places in the foothills had 2 to 5 inches of snow. Overnight rainfall totaled 0.33 inch at Stapleton International Airport where north winds gusted to 37 mph on the 25th.

In 1994…lightning struck a television transmitter on Lookout Mountain near Golden and burned out a switcher…which disrupted cable service for 2 hours.

Continue reading May 24 to May 30: This week in Denver weather history

May 17 to May 23: This week in Denver weather history

This Week In Denver Weather History
May 17 to May 23: This week in Denver weather history

As we move further into the severe weather season, we begin to see that transition in our look back at Denver weather history.  There are many more mentions of lightning, wildfires, tornadoes, hail and other season weather conditions.

14-18

In 1996…a period of unusually warm weather resulted in 4 record maximum temperatures in 5 days.  The record high temperatures were 87 degrees on the 14th…89 degrees on the 15th…and 93 degrees on both the 16th and 18th.  The temperature climbed to only 81 degrees on the 17th which was not a record.

16-17

In 1981…a heavy rain storm dumped 1 to 2 1/2 inches of rain across metro Denver.  Rainfall totaled 1.27 inches at Stapleton International Airport where north winds gusted to 38 mph on 17th.

In 1983…a very strong late spring storm dumped heavy snow over the Front Range.  Strong winds with the storm produced blizzard conditions at times.  Sustained winds were 20 to 40 mph with a peak gust to 55 mph at Stapleton International Airport.  The foothills received 1 to 2 feet of snow with 4 to 12 inches along the foothills.  Howling winds whipped the snow into drifts several feet deep…closing schools and highways.  Stapleton International Airport was forced to reduce flight operations…closing 2 of 4 runways and stranding hundreds of travelers.  Most of the damage and inconvenience caused by the storm was in power outages… Which occurred when wind and heavy wet snow caused hundreds of power poles to snap and topple.  About 20 square miles of Denver were blacked out.  Precipitation from the storm totaled 1 to 3 inches.  At Stapleton International Airport… Snowfall totaled 7.1 inches with a maximum snow depth on the ground of only 2 inches due to melting.  The high temperature of 40 degrees on the 17th was a record low maximum for the date.  Due to the heavy moisture content of the storm…widespread street flooding occurred on the 18th when much of the snow melted under the warm May sun and temperatures climbed to a high of 57 degrees.

In 1995…significant moisture and upslope flow caused flooding across metro Denver.  Moderate to heavy rains… Which began on the evening of the 16th…developed in the foothills and spread eastward over metro Denver throughout the night.  The heavy rains brought many creeks and small streams to bankfull or slightly over.  Locations along the foothills received between 3 and 4 inches of rainfall from the storm.  Boulder received 3.60 inches of rainfall for the 24-hour period…causing minor street flooding near small streams.  To the northwest of Boulder…a bridge which crossed Fourmile Creek was washed out.  Numerous rock and mudslides occurred in foothills canyons…closing portions of U.S. Highways 6 and 40 and State Highway 119 for a few hours at a time.  Rocks were piled 6 feet deep on a stretch of State Highway 119 along with Boulders as large as cars on U.S. Highway 6.  A parking lot near a creek in Golden caved in leaving a hole the size of an 18-wheeler.  Rushing water washed out a 50-foot stretch of a road in Westminster. Rainfall totaled 1.75 inches at Denver International Airport…but only 1.42 inches at the site of the former Stapleton International Airport.

17

In 1903…southwest winds were sustained to 42 mph with gusts to 45 mph from an apparent microburst which produced only a trace of rain.

In 1960…hail to 3/4 inch diameter was measured in Thornton. Golf ball size hail fell in Arvada.

In 1972…microburst winds gusted to 51 mph at Stapleton International Airport.

In 1975…hail 1/2 to 3/4 inch in diameter fell over western metro Denver.

In 1978…a small tornado touched down in south Aurora damaging 40 homes…6 to a considerable extent.  One garage was demolished and blown across the street.  Parts of roofs were completely blown away.  Several 2×4-inch boards were blown into the sides of houses.  Another small tornado in Parker damaged two airplanes.  Other funnel clouds were sighted over Northglenn and near Golden.

In 1985…a thunderstorm produced a total of 1.50 inches of rain in Brighton where 0.72 inches fell in 40 minutes. Small hail covered the ground…and there was some street and basement flooding.

In 1987…small hail piled up 4 inches deep in southwest Aurora.  There was also widespread street flooding and a few power outages.  Hail as large as 3/4 inch in diameter fell at Castle Rock.

In 2000…high winds occurred along and east of the Front Range foothills…as a deep surface low pressure center formed over the northeast plains of Colorado.  An amusement park in north Boulder received about 25 thousand dollars in property damage.  Peak wind reports included:  88 mph at the national wind technology center…84 mph in Boulder…and 80 mph at the National Center for Atmospheric Research Mesa Laboratory. A powder keg of severe weather…including tornadoes and thunderstorms producing large hail…damaging winds and heavy rain…occurred over the plains to the northeast of Denver.  The only severe weather reported across metro Denver was 1 inch diameter hail in Littleton.

18

In 1864…heavy rains combined with melting snow to cause much flooding on north clear creek in Blackhawk.  Many bridges on the road to Denver were washed away by the high water on clear creek.

In 1893…northwest winds were sustained to 56 mph with an extreme velocity to 60 mph.

In 1960…large hail to 1 inch in diameter damaged roofs and cars in metro Denver.  Heavy snow and rain in the foothills caused rock and landslides…which blocked some highways. There was widespread minor damage from lightning. Hail as large as 1 1/8 inch in diameter was measured at Stapleton Airport where winds gusted to 44 mph.

In 1975…a tornado touched down briefly just south of Buckley Field in Aurora.  A few minutes later the same tornado touched down in open country 8 miles northeast of Stapleton International Airport.  No damage was reported.

In 1985…3/4 inch hail fell just southeast of Aurora.

In 1988…lightning started a fire at a home in the foothills west of Boulder…causing 50 thousand dollars in damage.

In 1995…strong thunderstorms rumbled across metro Denver dropping mainly pea to marble size hail.  However…hail stones as large as 1 1/4 inches in diameter fell in Wheat Ridge and downtown Denver.  Hail piled up to 2 inches deep in Wheat Ridge and northwest Denver.

In 1996…the Buffalo Creek Wildfire started and spread rapidly on strong southwest winds at 20 to 30 mph.  Dry weather conditions contributed to the spread of the fire… Which burned nearly 12 thousand acres and destroyed 12 structures including some houses.

In 2001…a 19-year-old man was struck and killed by lightning as he was walking along the shoulder of U.S. Highway 36 in Westminster.

In 2003…hail to 3/4 inch in diameter was measured at Denver International Airport.

In 2010…a small tornado touched down near Firestone but did no damage.

18-19

In 2011…a severe thunderstorm in central Adams County produced large hail and heavy rainfall on the 18th. Large hail from 1 inch to 1 3/4 inches in diameter…was reported in Commerce City…2 miles south-southeast of Federal Heights…Northglenn… And 2 miles south of Thornton. In Commerce City…the storm uprooted trees and knocked out power lines. A carport was lifted off the ground and struck the power lines overhead. Heavy rain…from 1.0 to 1.5 inches fell in less than 2 hours in Commerce City and near Brighton. The combination of hail and strong winds broke windows in Northglenn. In the foothills…moderate to heavy snow showers developed overnight. Storm totals included: 10.5 inches at gold hill…9.5 inches… 3 miles west of Jamestown; 9 inches at Lake Eldora; with 6 inches… 11 miles southwest of Gilpin and 4 miles east-northeast of Nederland. At Denver International Airport…total rainfall over the 2-day period totaled 1.71 inches. In addition…a peak wind gust to 37 mph was recorded on the 18th.

Continue reading May 17 to May 23: This week in Denver weather history

May 10 to May 16: This week in Denver weather history

This Week In Denver Weather History
May 10 to May 16: This week in Denver weather history

As we move further into spring we begin to less winter-like weather and more spring weather.  In looking at Denver weather history we can see that transition with more mentions of severe rains, flooding, tornadoes and other spring and summer-like severe weather.

From the National Weather Service:

8-10

In 1979…4.3 inches of snow fell at Stapleton International Airport where northwest winds gusted to 30 mph on the 8th. Most of the snowfall…2.3 inches…occurred on the 9th. High temperature of only 35 degrees on the 9th equaled the record low maximum for the date.

9-10

In 1889…heavy rainfall totaled 2.15 inches in downtown Denver.  The cold rain was mixed with snow at times overnight.  Temperatures on the 10th ranged from a high of 38 degrees to a low of 32 degrees with north winds sustained to 22 mph.

In 2003…a late spring snowstorm hammered the mountains… Eastern foothills…and urban corridor.  The heaviest snowfall occurred north of interstate 70.  The heavy wet snow caused damage to trees throughout metro Denver and downed power lines.  About 40 thousand people along the urban corridor were without power.  Storm total snowfall amounts included:  11.5 inches in Louisville… 8 inches in Boulder and Broomfield; 7 inches in Thornton…Broomfield…at Denver International Airport… And at the site of the former Stapleton International Airport; and 6 inches 4 miles east of Denver.  Snowfall ranged from 4 to 9 inches across extreme southern weld County.  In the foothills…15 inches of snow fell near Jamestown…9 inches at Rollinsville and Rawah…with 8 inches at Chief Hosa and atop Lookout Mountain. The snow was accompanied by thunder on the afternoon of the 9th at Denver International Airport where west winds gusted to 25 mph on the 9th and north winds gusted to 22 mph on the 10th.

10

In 1875…a windstorm sand-blasted the city from 10:00 am until midnight.  Northwest winds sustained to 60 mph brought clouds of sand…which caused high damage to unfinished buildings.

In 1912…a vigorous cold front produced strong north winds and rain.  North winds were sustained to 48 mph with gusts as high as 60 mph.  Rainfall totaled 1.10 inch.

In 1935…no precipitation occurred…making this one of only two days without precipitation during the entire month.  The other day was the 21st.  Precipitation totaled 4.95 inches for the month.

In 1956…northwest winds gusted to 53 mph at Stapleton Airport where the visibility was briefly reduced to 1/2 mile in blowing dust.

In 1974…strong winds caused 30 thousand dollars in damage to a building under construction in Lakewood.  Microburst winds gusted to 46 mph at Stapleton International Airport.

In 1988…lightning struck a house in Boulder…setting it afire.  The house…valued at 170 thousand dollars…was a total loss.

In 1989…golf ball size hail fell over southeast Denver near the junction of I-25 and I-225.  Hail to 3/4 inch in diameter fell over southeast Aurora.  Only 3/8 inch hail fell at Stapleton International Airport.

In 1991…high winds up to 63 mph raked the eastern foothills. Winds estimated to 50 mph tore a roof from a home in Lafayette.  A tower at Jefferson County stadium in west metro Denver was blown over by the high winds.  No injuries were reported.  Southeast winds gusting to 48 mph at Stapleton International Airport produced some blowing dust.  The temperature climbed to a high of 86 degrees… Equaling the record maximum for the date.

In 2005…severe thunderstorms produced hail as large as 2 inches in diameter in and near Longmont.

10-11

In 1918…post-frontal snowfall totaled 4.7 inches in downtown Denver.  Northwest winds gusted to 19 mph on the 10th.

In 1923…winds were strong and gusty on both days.  Northwest winds were sustained to 40 mph with gusts to 44 mph on the 10th.  North winds were sustained to 39 mph with gusts to 46 mph behind an apparent cold front on the 11th.

10-12

In 2011…a spring snowstorm brought heavy snow to the Front Range foothills and palmer divide. Storm totals included: 18 inches…4 miles south-southeast of Pinecliffe; 16 inches in Coal Creek Canyon; 15 inches…4 miles west-southwest of Eldorado Springs; 13 inches at Gold Hill…12 inches… 4 miles west-southwest of Conifer and 4 miles northwest of Elizabeth; 11.5 inches…6 miles southwest of Evergreen and 4 miles east-northeast of Nederland; 11 inches…3 miles east of Jamestown and 10.5 inches…3 miles east of Franktown and 3 miles south of Golden and 10 inches…10 miles north of Elizabeth. At Denver International Airport… 1 inch of snowfall was observed.

11

In 1879…an apparent cold front during the afternoon produced sustained north winds as high as 60 mph and great clouds of blowing dust.  The dust filled the air until the thunderstorm rain began…which produced 1.46 inches of rainfall.  The rain ended during the evening.

In 1900…southwest winds were sustained to 40 mph with gusts to 46 mph.

In 1958…a microburst caused a brief wind gust to 55 mph at Stapleton Airport.

In 1963…south-southwest winds gusted to 48 mph at Stapleton Airport.  Winds May have been stronger over west Denver where some buildings were damaged.

In 1998…large hail fell over south metro Denver.  Hail as large as 1 1/4 inches in diameter was measured in Parker with 1 inch hail recorded in Littleton and 4 miles south of Lakewood in Jefferson County.  Hail to 3/4 inch diameter was measured in Douglas County…11 miles west- northwest of Parker.

11-12

In 2014…a strong storm system moved from southwest Colorado and produced heavy snow in and near the Front Range foothills and metro Denver. The snow was heaviest in the foothills where up to 2 1/2 feet of snow was observed. In the foothills… Storm totals included: 30 inches near Pinecliffe; 29 inches… 8 miles northeast of Four Corners; 28 inches near Pingree Park; 27 inches near Allenspark; 20.5 inches near Idaho Springs; 19.5 inches at Gold Hill; 19 inches near Genesee; 18 inches near Blackhawk; 17 inches at Aspen Springs; 16.5 inches near Ward; 13.5 inches at bergen park; with 11 inches at Evergreen. Along the urban corridor and Palmer Divide…storm totals included: 10.5 inches at Eldorado Springs; 10 inches at Ken Caryl; 9 inches at Superior; 8 inches near Morrison; 7.5 inches in Broomfield and Highlands Ranch; 7 inches in Denver… Near Franktown…Golden… Lakewood and Highlands Ranch; 6 inches…5 miles northeast of Westminster… 7 miles south of Lyons and near Parker; with 5.5 inches at Aurora. At Denver International Airport…1.1 inches of snowfall was observed… Along with 0.9 inches of water.

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In 1875…two forest fires on the eastern slope of the foothills were visible from the city.

In 1904…north winds were sustained to 40 mph with gusts to 48 mph.

In 1950…brilliant and complete primary and secondary rainbows arching across the sky were observed from Stapleton Airport.

In 1951…a wind gust to 51 mph was recorded at Stapleton Airport.

In 1984…winds gusted to 69 mph in Boulder.  Northwest winds gusted to 47 mph at Stapleton International Airport.

In 1987…a small weak tornado touched down for about 2 minutes in southeast Denver.  The twister hit a car dealership…blowing about a dozen windows out of cars and shattering four skylights on the building.  Some tin roofing was blown off a patio a block and a half away.  The tornado also downed a power pole.  Damage at the dealership was estimated at 10 thousand dollars.  A man was slightly injured by lightning in northwest Aurora.

In 1995…several funnel clouds were sighted near Parker. One of the funnels produced a short-lived debris cloud on the ground in an open field.  No damage was reported.

Continue reading May 10 to May 16: This week in Denver weather history

Thornton’s May weather preview: Everything from snow to severe storms

Thornton, Colorado May 2013 weather preview.
Thornton, Colorado May 2015 weather preview.

Colorado’s famously highly variable weather seems to showcase itself during the month of May when a variety of weather conditions can be seen.

Winter-like temperatures and snow are possible as are mid-summer like temperatures or the more typical spring severe weather.

As the month starts out in 2015 we are going to enjoy a mild period with unseasonably warm temperatures but with unsettled conditions.  Long range forecasts lean toward overall warmer than normal temperatures and above normal precipitation.

However the month can bring extremes.  Snow is not entirely uncommon during the month, oftentimes causing damage to newly bloomed trees.  More common however is severe weather, particularly in the latter half of the month.  Thunderstorms become more frequent and their associated hazards – lightning, wind, hail and tornadoes – are usual visitors.

For a complete look at what lies ahead for the month of May, check out our full preview here.