The tornado that struck Aurora, Colorado has been rated an EF1 with 100 mph winds by the National Weather Service. Image courtesy Sean Strachan. Follow the link below to go to Examiner.com for more images.
The tornado that touched down in the Denver suburb of Aurora and caused damage to a local mall and apartment complex has been rated an EF1 by the National Weather Service. After two days of evaluations, the service said that the twister most likely had winds of 100 mph, placing it in the middle of that rating.
The four other twisters that struck the area will be rated later this week. Because they were short lived and struck in open areas, they mostly likely will be rated as EF0 twisters with winds from 65 mph to 85 mph.
The other tornadoes were reported in the area of 144th and I-25, one was reported five miles south of Bennett, one five miles south of Deer Trail and one three miles north of Byers.
A funnel cloud near Thornton on Sunday, June 7, 2009. Image courtesy John Wagner, Warrior Legacy Foundation. View our slideshow below for more images.
For a brief period of time this afternoon, Thornton and western Adams County were under a Tornado Warning as a funnel cloud was spotted passing. Thankfully the storm quickly weakened and the threat diminished. The image at the right is courtesy John Wagner of the Warrior Legacy Foundation. This was from approximately 136th & Washington looking northwest.
View images from ThorntonWeather.com visitors in our slideshow below. Also check out two videos of the twister below!
Please stay aware of the latest severe weather in Thornton. As of this writing a Severe Thunderstorm Warning remains in effect and conditions could rapidly deteriorate again.
June 7 to June 13 - This week in Denver weather history
An extremely eventful week in weather history showing just how varied conditions can be. We of course see typical spring weather like tornadoes and hail but also a touch of snow and this week also marks the anniversary of the start of the Hayman Fire.
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In 1921…heavy rainfall for nearly a week…on top of streams already swollen by mountain snowmelt…produced widespread flooding over the South Platte River basin…including the tributaries through the canyons to the west and southwest of Denver. Heavy rainfall over the 6-day period totaled 3.36 inches in Boulder…4.98 inches in Morrison…4.27 inches in Castle Rock…and 2.94 inches in the city of Denver. Rainfall amounts in the foothills were estimated between 3 and 6 inches. The narrow-gage tracks of the Colorado and southern railroad were destroyed in the Platte Canyon. From the mouth of the canyon through the city to near Brighton… The river spread from 1/2 to nearly 1 1/2 miles wide… Flooding farm and pasture land and destroying or damaging many bridges. In the city…many businesses along with as many as 500 homes were inundated…forcing their evacuation. Bridges were swept away. The high waters flooded the rail yards and stock yards in lower downtown…closing three adjacent packing houses. The heavy rains also caused flooding on Boulder creek in Boulder on the 6th.
6-7 in 2004…a brief hot spell produced 3 temperature records. High temperatures of 95 degrees on the 6th and 98 degrees on the 7th were record maximum temperatures for the dates. Low temperature of 68 degrees on the 7th was a record high minimum for the date.
In 2007…an unusually strong storm system brought very strong winds to the Front Range foothills and urban corridor. Peak gusts included: 92 mph at Boulder…85 mph…2 miles southwest of Boulder…83 mph…10 miles south of Boulder and 55 mph at Denver International Airport. High winds forced the closure of Mt. Evans Road and Trail Ridge Road. Several trees were uprooted across the urban corridor. In Aurora… The driver of a car was injured when some building material blew off the Fitzsimmons complex. The debris landed on the car and knocked the driver unconcious. The wind forced the cancellation of 60 flights at Denver International Airport. Xcel reported outages in Boulder…Denver…Lakewood and Longmont.
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In 1904…a thunderstorm produced south winds to 40 mph with gusts to 50 mph…but only a trace of rain.
In 1942…heavy thunderstorm rainfall in south Denver caused flooding of shops…stalled motorists…and halted tramway service temporarily. Lightning damaged houses…but there was no loss of life. Precipitation totaled 0.53 inch in downtown Denver.
Damage along Washington was extensive from the tornado that struck Thornton on June 3, 1981. (City of Thornton archives)
It was 28 years ago today that the worst tornado to ever strike the Denver metro area hit Thornton. June 3, 1981 is a day that will forever be remembered by longtime residents of the north metro area.
Last year the Northglenn-Thornton Sentinel did a story about it which you can read by clicking here. Also, below is the entry from the National Weather Service’s history calendar – it is very interesting and serves as a good reminder that severe weather can strike anywhere.
In 1981…severe thunderstorms produced tornadoes over metro Denver. The first tornado touched down at the intersection of Alameda Ave. And Sheridan Blvd. The twister moved north along Sheridan Blvd….damaging businesses…apartment buildings…homes…and vehicles. Over ten homes were unroofed. The roof of one landed in the middle of a neighborhood park. At least 10 mobile homes were wrecked.
The tornado curved to the northeast into northwest Denver… Hopping up and down in several places. Very strong winds outside the actual funnel caused 20 to 30 thousand dollars in damage in downtown Denver. The third floor of one old building was demolished. No major injuries were reported from the tornado…although several people were hurt slightly in traffic accidents on Sheridan Blvd. in the confusion caused by the storm. Damage in Lakewood alone was estimated at 200 thousand dollars.
At the same time… The worst tornado to ever hit metro Denver struck Thornton. Coming from the same thunderstorm that spawned the Denver twister…the Thornton tornado tore a swath through the heart of the city. 87 homes were destroyed…110 others damaged at least moderately. In all…600 homes in a 100 block area sustained some damage. The twister also hit shopping centers…several restaurants…and other buildings. Seven of the 42 injured were considered serious. The storm was strong enough to snap lamp posts in half and drive a 6- inch slab of wood 2 feet into the ground. Damage was estimated at up to 50 million dollars.
The same storm that struck Thornton produced another damaging tornado that touched down in the northwest section of Fort Lupton. This twister damaged 16 homes and numerous cars and campers. Two children were slightly injured when the car they were in was knocked about and its windows shattered by the storm. The twister also damaged two commercial buildings. Damage was very spotty…and observers said the storm hopped up and down at least 3 times. Dollar damage was estimated at 500 thousand dollars.
The thunderstorm complex that produced 3 damaging tornadoes also dropped large hail which damaged many cars over northwest Denver. One to 2 inches of rain fell in less than an hour…flooding a mobile home park with 3 to 4 feet of water on the northwest edge of Denver. The high water damaged about half of the 392 homes in the park. Local flooding was also reported in other areas across metro Denver. A tornado was also sighted near Franktown…but caused no damage. A thunderstorm wind gust to 52 mph was recorded at Stapleton International Airport.
Air France Flight 447 is missing over the Atlantic this morning and presumed lost. (AP Photo)
An Air France jet en route from Rio de Janeiro to Paris carrying 228 people appears to have been lost over the Atlantic Ocean. The plane which disappeared approximately 190 miles northeast of the Brazilian city of Natal may have been brought down by severe weather the plane was flying through at the time it lost contact with air traffic controller.
Air France Flight 447 is reported to have hit strong turbulence and possibly lightning as the result of a thunderstorm. Air France says the plane, an Airbus A330, left Rio de Janeiro at 7:00pm local time and approximately four hours late the plan sent an automated signal indicating electrical problems. The airline said the plane “crossed through a thunderous zone with strong turbulence.” The automated message was received 14 minutes later at 0214GMT (10:14 pm EDT Sunday) “signaling electrical circuit malfunction.”
Francois Brousse, head of communications at Air France, “The plane might have been struck by lightning. It’s a possibility.”
Is global warming responsible for fewer tornadoes in 2009? Stu Ostro of the Weather Channel thinks so. Image courtesy NSSL.
Stormchasers across Tornado Alley have been frustrated this spring by what seems to be a lack of tornadoes and severe weather. Indeed, VORTEX2, the largest tornado field study ever, has been running for more than two weeks now and has not seen one twister. Last week, Weather Channel Senior Meteorologist Stu Ostro speculated that global warming was the cause.
In a segment with on-air meteorologist Stephanie Abrams, Ostro explained that the jet stream lingering over Canada and a continual ridge of high pressure were suppressing severe weather. Without the collision of low and high pressure (among other factors), tornadoes and supercell thunderstorms have a hard time forming.
Ostro continued his explanation saying that atmospheric pressure in the Northern Hemisphere’s mid-latitudes between 30 and 60 degrees has increased steadily since 1970. He then overlaid a chart showing this increase with that of a chart that shows global average temperatures having increased over the same period. As he says in his blog entry, “That parallels remarkably well the trend of globally-averaged temperatures, which has also shown a significant rise since the mid 1970s.”
Denver is historically Thornton's true severe weather month.
June is historically Denver’s severe weather month and severe thunderstorms, tornadoes and hail are notorious visitors to Denver and across eastern Colorado during the month. In fact, over 40 percent of the tornadoes that occur in Colorado are observed in June and these are typically the most destructive of the year. Severe thunderstorms have also caused major property damage across the Front Range during the month.
In just the last 25 years or so, there have been some particularly notable storms in June. Tornadoes have struck the metro area including one that longtime Thornton residents will recall on June 3, 1981. 53 residents were injured, 25 homes were destroyed and 239 other structures were damaged. Others tornadoes in the metro area include southeast Denver and Aurora on June 8, 1986 and east Denver on June 13, 1984. Severe thunderstorms occurring on June 13, 1984 dumped large hail making it one of the worst and the second costliest storm in Denver history. More recently, on June 20, 2001, a major hail storm moved across Denver International Airport dropping hailstones as big as two inches in diameter. Damage was extensive on and near the airport.
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.
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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.
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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.
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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.
This funnel cloud, one of many across the metro area Sunday, was spotted over Highlands Ranch. Image courtesy Tracee Hendershott.
Thus far the weather today has been much quieter than it was yesterday when thunderstorms brought severe weather to most of the metro area. Southern Thornton has seen a good bit of rain but areas farther north have had very little.
Earlier today, local law enforcement did report a funnel cloud over 104th and Colorado Blvd from a thunderstorm that was moving through the area. Reported at 12:47pm, the funnel moved to the east at 15 mph and quickly disappated. Unlike yesterday when many funnel clouds – and three tornadoes – were reported, this is the only such report thus far today.
Do you have pictures of this weekend’s severe weather? Send them to info@thorntonweather.com and we will show them on our site!
May 24 - 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.
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.
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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.
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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.
