Thornton, Colorado, USA
UpdatedTue, 25-Oct-2016 9:35am MDT 


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Relief arrives in the form of cooler temps, possibly damp conditions

Wednesday, August 24th, 2016 5:15am MDT

With the passage of a cold front and a trough digging in, Thornton will see notable changes in our weather Wednesday. The mercury will stay some 10 degrees below normal and maybe, just maybe, we will see some precipitation.

Mostly cloudy skies will be above throughout the day today. Look for highs to top out in the mid-70s, well below the average of 86 degrees for the date.

Some light showers will be possible this morning with the best chances coming between 9:00am and 11:00am. Then, this afternoon, heating should help bump up instability and bring chances for thunderstorms, particularly after 4:00pm. Unfortunately there isn’t a whole lot of moisture with this system but with any luck we will eek out something measurable.

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Tuesday brings cooler temperatures, slight chance for storms

Tuesday, August 23rd, 2016 5:17am MDT

We begin to see a change in the overall weather pattern today with the passage of a cold front. That is going to lead to temperatures right near normal and a bit of a chance for showers later.

We start out with mostly sunny skies that will be with us for the first part of the morning. Cloud cover will then build as the front approaches. As the front pushes through in the early to mid-afternoon, wind speeds will increase and become breezy into the evening.

Temperatures will be topping out today right around the average for the date of 86 degrees. That will occur in the early afternoon then we will see decreasing temps with the passage of the front.

As far as thunderstorms go, we see just a slight chance from about 3:00pm through the night. Any that do form are expected to bring mainly gusty winds, lightning and perhaps a bit of rain. Live radar.

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The heat is on for Thornton’s Monday

Monday, August 22nd, 2016 5:00am MDT

We are set to have our hottest day of the week right off the bat today. The good news is though that we will then see mercury readings near normal tomorrow and then cool down nicely for the balance of the week.

For today we kick things off with mostly sunny skies. There will be some increase in cloud cover by mid-morning but still with a good bit of sun for the balance of the day. Temperatures will be climbing to a high of around 93 degrees, well above the average for the date of 86 degrees.

Daytime hours should be dry and calm. This evening we expect a bit of an uptick in moisture and that will bring just a slight chance for thunderstorms after about 6:00pm.

As for the rest of the week, check out the extended weather forecast here.

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August 21 to August 27: This week in Denver weather history

Sunday, August 21st, 2016 1:51pm MDT
This Week In Denver Weather History

August 21 to August 27: This week in Denver weather history

Denver’s weather is not often boring. Lightning, hail, tornadoes and even swarms of grasshoppers have made appearances this week in Denver weather history.

From the National Weather Service:


In 1875…grasshoppers appeared in great numbers at 10:00 am on the 19th. Thousands landed on the ground. The streets were literally covered with them. Swarms of grasshoppers were seen on each day. All gardens in the city were devastated…and in the countryside the grasshoppers were very destructive to ripened grain. On the 30th the grasshoppers were so numerous as to almost darken the sun.


In 1876…heavy thunderstorm rain and hail struck the city. Hail stones as large as partridge eggs accumulated to a depth of 1 1/2 feet over eastern portions of the city. The heavy rainfall flooded streets and gutters. However… No significant damage was reported. Rainfall totaled 0.85 inch in central Denver.

In 1903…a thunderstorm produced west winds sustained to 42 mph with gusts to 48 mph.

In 1957…heavy thunderstorm rainfall and hail over the bear creek basin flooded portions of State Highway 8 in and near Morrison. There was also minor property damage in Morrison.

In 1995…a 68-year-old woman was struck by lightning while standing near a tree in Brighton.

In 2006…a severe thunderstorm produced 7/8 inch diameter hail in Franktown.


In 1898…an apparent thunderstorm produced southwest sustained winds to 40 mph with gusts to 43 mph.

In 1903…a late afternoon thunderstorm produced rain…hail… And east winds sustained to 40 mph with gusts to 44 mph.

In 1904…the lowest recorded temperature in August…40 degrees…occurred. The same temperature also occurred on three consecutive days…August 24…25…and 26 in 1910.

In 1965…heavy rain and hail caused some damage from flooding over northern Douglas County from Castle Rock to Franktown.

In 1981…thunderstorms moved across metro Denver. At least 5 funnel cloud sightings were reported. Funnel clouds were seen at 96th Ave. and Sheridan Blvd. And at 92nd Ave. and Federal Blvd. in Westminster and 7 miles north of Stapleton International Airport. Lightning injured two people in Boulder. A quarter inch of rain fell in just 5 minutes in Brighton. Up to 3/4 inch of rain doused Parker in 30 minutes.

In 1983…3/4 inch diameter hail was reported at Kittredge… Along with 0.60 inch of rain in 25 minutes.

In 1984…a thunderstorm dumped 4 inches of rain on Brighton in 90 minutes…causing extensive street flooding in the downtown area.

In 1987…over an inch of rain fell in 24 hours throughout most of metro Denver. A public library suffered water damage to the ceiling…carpet…and a few books. Rainfall was 0.76 inch at Stapleton International Airport.

In 1990…lightning knocked out power to about 2500 homes in Lakewood for about an hour.

In 1991…National Weather Service personnel at Stapleton International Airport sighted an apparent tornado briefly on the ground 3 miles west-northwest of the airport. No damage was reported.

In 1995…lightning struck 3 electrical power substations in Louisville. Residences of more than 4500 people were without power from 30 minutes to more than an hour.

In 1996…between 1 and 3 inches of rain fell across metro Denver. As a result…several low lying areas were flooded. A bicyclist was swept into a fast moving creek when he tried to cross a flooded bike path. The man was washed downstream about 15 feet before getting snagged by a tree stump. He and a man who tried to rescue him received minor injuries. The heavy rain caused numerous power outages…false fire alarms…and traffic accidents. In Lakewood…telephone service to around 60 thousand residents was knocked out when a switching center was flooded. Funnel clouds were sighted near Chatfield Reservoir and Highlands Ranch.

In 2000…lightning sparked a blaze which gutted a 10-unit apartment building in Highlands Ranch. Twenty-eight people were left homeless. Damage was estimated at 2 million dollars.

In 2007…severe thunderstorms produced large hail…up to 1 1/4 inches in diameter…in the vicinities of Castle Rock… Elizabeth and Franktown.

In 2013…flash flooding occurred in central Douglas County with numerous road closures reported. One of the closures occurred at the Tomah Road exit along I-25…south of Castle Rock.  The closure backed up all I-25 the way to Castle Rock. At Denver International Airport…1.94 inches of precipitation was recorded…which set a new record rainfall for the date. The old record was 0.75 inches… set back in 1953.


In 1987…some locations in metro Denver had a total 3-day rainfall of 2 to 4 inches. Rainfall totaled 0.96 inch at Stapleton International Airport.


In 1900…northwest winds were sustained to 42 mph with gusts to 49 mph.

In 1921…a thunderstorm cloudburst produced 2.20 inches of rainfall in an hour over downtown Denver. This is the greatest 1 hour rainfall on record at the official observing site in the city. Precipitation totaled 2.93 inches…which is the greatest calendar day precipitation ever recorded in August.

In 1941…one man was killed by lightning about 2 miles from the official weather station in downtown Denver.

In 1962…a home near Boulder was destroyed by a lightning- caused fire.

In 1968…strong winds buffeted Boulder briefly during the early morning hours. At the National Center for Atmospheric Research…winds averaged 55 mph with gusts to 85 mph. Damage was minor. Northwest winds gusted to 31 mph at Stapleton International Airport.

In 1977…lightning damaged at least 6 homes in Aurora.

In 2008…a landspout touched down near Westcreek in Douglas County. One man was seriously injured when he tried to escaped several falling trees in his ATV. One of the trees struck his back and broke two vertebra. Another camper narrowly escaped injury. Seconds after he back up his truck…a tree came down where it had been parked.


In 1880…a thunderstorm produced vivid lightning and heavy rainfall…which caused flooding over the eastern part of the city including the brick yards. There was no rainfall recorded in downtown Denver.

In 1910…an apparent dry cold front caused a remarkable drop in temperature. From 3:00 pm until midnight the temperature fell from a high of 93 degrees to a low of 40 degrees. Northeast winds were sustained to 44 mph during the late afternoon.

In 1946…heavy rain near Idledale caused flooding on bear creek at Morrison…which resulted in one death when a woman was swept from her stranded car and drowned.

In 1973…strong winds blew down a few power lines and hail up to 3/4 inch diameter fell in southeast Aurora.

In 1984…heavy rain hit the south Denver area. Over an inch fell in less than an hour at both Castle Rock and Sedalia.

In 1992…heavy rains caused flash flooding across parts of metro Denver. Rainfall amounts of 1 to 3 inches fell with the hardest hit areas being the southwest and central parts of metro Denver. Bear Creek rose above bankfull near Idledale with flood waters moving into southwest metro Denver. Mud and rock slides along Colorado highway 74 west of Morrison were reported. The confluence of Cherry Creek and the South Platte River in downtown Denver also went out of its banks…flooding bike paths. Rainfall totaled 1.98 inches at Stapleton International Airport where light to moderate rain fell most of the day. Heavy rain and fog briefly reduced the surface visibility to 1 1/2 miles. The temperature climbed to a high of only 58 degrees…which was a record low maximum for the date.

In 2002…hail to 7/8 inch in diameter was measured in southwest Denver.

In 2008…several landspout tornadoes developed along a boundary to the southeast of the Denver metropolitan area during the Democratic National Convention. In northwest Elbert County… Minor damage was reported. The damage consisted of downed power lines…broken windows and an out building. Severe thunderstorms also produced very heavy rain and large hail… Up to one inch in diameter. In southwest Douglas County… Heavy rain caused flash flooding near the town of Westcreek. A mudslide closed State Highway 67. The road in the YMCA camp shady brook was also washed out and some bridges were damaged.


In 1910…the lowest temperature ever recorded in August…40 degrees…occurred on each of these days and on August 22… 1904. The unusually cold weather for so early in the season brought sub-freezing minimum temperatures to much of the Colorado northeastern plains.


In 1951…a microburst produced a southwest wind gust to 50 mph at Stapleton Airport. Only a trace of rain was observed.

In 1964…thunderstorm winds gusted to 59 mph and caused some blowing dust at Stapleton International Airport.

In 1994…lightning struck a power pole in Louisville and caused a two-hour power outage.

In 2008…an unoccupied home was struck by lightning in Aurora… Causing 75 thousand dollars in damage to the roof.


In 1944…one of the most destructive hailstorms in the city in a decade caused damage estimated at nearly one million dollars. The storm occurred within a period of 10 to 30 minutes…between 2:00 pm and 3:00 pm. The hail varied in size from very small to as large as 1 1/2 inches in diameter. Hail covered the ground to a depth of 5 to 6 inches in some sections of the city. Several people were cut by broken glass. The hail and heavy rain flooded underpasses to a depth of 6 feet…and the occupants of stalled autos had to be rescued. Sewers were unable to handle the sudden amount of water and water backed up and flooded a number of basements. A few first floors of buildings were flooded. The water department had a busy time replacing manhole covers that had been displaced by the water pressure. Trees were stripped…one was severely broken…and telephone lines were downed. Roofs…windows… Automobiles…awnings…and gardens were severely damaged. Flowers and gardens in some sections of the city were a total loss. Greenhouses were extensively broken with an estimated 20 carloads of glass shattered. Vegetable and truck crops in and around the city were severely shredded. The next day the American Red Cross was designated by the War Agency to grant any and all priorities needed to obtain materials and supplies to replace and repair the damage. In downtown Denver…the thunderstorm produced 0.95 inch of rain and heavy hail along with sustained northwest winds to 25 mph.

In 1961…strong winds blew in the walls of a warehouse under construction in Denver. Two workmen suffered a fractured foot and body bruises.

In 2014…two men in central Denver were struck by lightning as they sat under a tree to avoid a heavy downpour. One of the men was unconscious and had no pulse when emergency responders arrived. He was immediately taken to Denver Health was listed in critical condition. The other victim suffered less severe injuries. He was treated at the scene and hospitalized…then released a few hours later.

» Click here to read the rest of August 21 to August 27: This week in Denver weather history

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Thornton’s weekend starts out feeling fall-ish, then warms back up

Friday, August 19th, 2016 5:13am MDT

A nice little change in store for our weather over the three-day period. Cooler and (hopefully) wetter conditions start things off Friday to be followed by drier conditions Saturday then a rebound of temperatures Sunday.

For today we will have partly sunny skies above for most of the day. A sprinkle of rain may be seen in the morning and then this afternoon chances for showers and thunderstorms in increase. Temperatures will be topping out only in the mid-70s.

Saturday brings drier conditions but with very comfortable mercury readings. Clouds will be decreasing tonight and through tomorrow morning leading to mostly sunny skies Saturday afternoon. We see just a slight chance for thunderstorms. Highs tomorrow will again be in the mid-70s.

High pressure makes its return on Sunday and that will lead to warmer temperatures. Sunny to mostly sunny skies will be above as we head for a high in the mid-80s. Right now we aren’t expecting any storms on that day.

Have a great weekend!

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NASA satellite imagery shows California’s monstrous Blue Cut Fire

Thursday, August 18th, 2016 9:31am MDT
NASA satellite imagery shows the monstrous Blue Cut Fire in California. (NASA)

NASA satellite imagery shows the monstrous Blue Cut Fire in California. Click for a larger view. (NASA)

From NASA:

The Blue Cut Fire, just outside of Los Angeles, is a quickly growing fire that is currently an imminent threat to public safety, rail traffic and structures in the Cajon Pass, Lytle Creek, Wrightwood, Oak Hills, and surrounding areas. An estimated 34,500 homes and 82,640 people are being affected by the evacuation warnings that have been issued. This wildfire started on August 16, 2016 and the cause is unknown. In the last two days the fire has grown to 31,689 acres with 1584 personnel on scene. 178 engines, 26 crews, 10 air tankers, 2 Very Large Air Tankers (VLATS), and 17 Helicopters, including night flying helicopters. Additional firefighters and equipment have been ordered and will be responding directly to the fire. An unknown number of structures are damaged and destroyed. A smoke advisory has been issued for portions of San Bernardino Country.

Unfortunately extreme weather is continuing in the area with hot, dry and breezy (20 mph with gusts to 30 mph) conditions. Very poor relative humidity will continue. All of these will hinder fire fighting efforts and may increase fire spread.

NASA’s Suomi NPP satellite collected this natural-color image using the VIIRS (Visible Infrared Imaging Radiometer Suite) instrument on August 17, 2016. Actively burning areas, detected by thermal bands, are outlined in red. NASA image courtesy Jeff Schmaltz LANCE/EOSDIS MODIS Rapid Response Team, GSFC. Caption by Lynn Jenner with information from Inciweb.

Suomi NPP is managed by NASA, NOAA and the U.S. Department of Defense.

Last Updated: Aug. 18, 2016
Editor: Lynn Jenner

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Adoring press detail Obama’s golf, vacation while Louisiana is underwater

Thursday, August 18th, 2016 9:22am MDT

Three days of heavy downpours have brought historic flooding to Louisiana, where 30 parishes have declared to be a disaster, and the death toll has climbed to 13. The U.S. Coast Guard and other first responders rescued more than 20,000 people over the weekend, as the massive flooding inundated areas in and around Baton Rouge. More… » Click here to read the rest of Adoring press detail Obama’s golf, vacation while Louisiana is underwater

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August 14 to August 20: This week in Denver weather history

Thursday, August 18th, 2016 5:59am MDT
This Week In Denver Weather History

August 14 to August 20: This week in Denver weather history

Severe weather is a fact of life in Colorado during the summer months and while August is historically relatively calm, that isn’t always the case. In our look back at this week in Denver weather history we see the dangers of lightning, incidents of large hail and flooding rains and even a tornado.

From the National Weather Service:


In 1960…a bolt of lightning struck a man in Henderson… Causing serious burns.

In 1962…the temperature climbed to a high of 100 degrees at Stapleton Airport.

In 1968…a young man on a golf course in Denver was injured when lightning struck a tree under which he was standing. Lightning caused minor damage to a house in Denver. Heavy thunderstorm rain caused local street flooding. One inch diameter hail fell at Jefferson County Airport near Broomfield.

In 1973…winds as high as 85 mph damaged 20 aircraft at the Arapahoe County airport…now centennial airport.

In 1977…three tornadoes were sighted in Bennett. A man suffered a broken leg when hit by a flying board. He was outside his camper home…which was destroyed. All windows were broken in a near-by farmhouse where some shingles were ripped off and a 2 car garage was knocked down. Several vehicles were damaged and a cat…some rabbits…and chickens were killed. A broken oar from a boat was driven into the side of a house. A mobile home was overturned. One old barn was destroyed. Half a dozen homes and several agricultural buildings were damaged just west of State Highway 79.

In 1978…high winds produced much blowing dust…causing many traffic accidents in the Denver-Boulder area. Winds gusts of 70 to 101 mph were recorded. Northwest winds gusted to 44 mph at Stapleton International Airport.

In 1980…lightning hit two power poles in Littleton…causing 400 dollars in damage. Rainfall of 1.23 inches in a short time caused minor flooding…which included damage to a ground floor apartment and partially submerging a few vehicles in water. Thunderstorm rainfall totaled 0.98 inch at Stapleton International Airport.

In 1983…2.10 inches of rain drenched Golden in an hour with similar amounts in Lakewood and Boulder. Over ten thousand dollars worth of plants were washed away at a nursery in Lakewood.

In 1997…twelve motorists were injured in a multi-car accident when strong microburst winds estimated to 50 mph blew blinding dust across I-70 near Bennett.

In 1998…lightning struck a hydro-electric plant in Nederland… Causing a power outage. Residents in the foothills west of Boulder…including Nederland…Ward…Eldora…Jamestown… And Gold Hill…were without power for about an hour.

In 2006…heavy thunderstorm rainfall near Deckers washed away some the banks along State Highway 67 between Deckers and Westcreek. Several driveways on both sides of the highway were also damaged.


In 1899…a thunderstorm produced southwest sustained winds to 43 mph with gusts to 46 mph.

In 1972…a pilot reported a funnel cloud briefly touching the ground in open fields…17 miles east-northeast of Stapleton International Airport.

In 1980…thunderstorm winds gusted to 55 mph in Boulder.

In 1982…brief heavy rain and winds estimated as high as 70 mph occurred in the conifer-Evergreen area. No damage was reported.

In 1990…lightning triggered a small attic fire in a house near Sedalia…20 miles south of Denver. A furious lightning storm caused widespread power outages across southern sections of metro Denver. One lightning bolt knocked out an electrical substation…causing a 90-minute blackout in southeast Denver affecting nearly 10 thousand homes and businesses.

In 2007…severe thunderstorms produced large hail…up to 2 inches in diameter…near larkspur. Extensive damage to vehicles in the area was reported.

In Parker…lightning struck a residence. The ensuing fire damaged the attic and top floor; causing $100000 in property damage.

In 2008…at least three homes were hit by lightning during the early morning hours in Arapahoe County. Lightning also struck two homes in Castle Rock…damaging the roofs.


In 1902…a thunderstorm produced west winds sustained to 48 mph with gusts to 60 mph…but only a trace of rain.

In 1952…a thunderstorm wind gust to 50 mph was recorded at Stapleton Airport.

In 1960…lightning struck a warehouse in central Denver… Causing 8 thousand dollars in damage to the building and stored electrical equipment.

In 1975…large hail…1 1/2 to 1 3/4 inches in diameter…fell about 4 miles north of Castle Rock. Hail caused some minor damage in Aurora. A funnel cloud was reported 25 miles east of Denver near Bennett.

In 1981…a tornado touched down briefly in open country just to the east of Aurora. No damage was reported.

In 1982…a thunderstorm wind gust to 61 mph was recorded at Buckley Field in Aurora. At the same time almost an inch of rain flooded and closed streets in south Aurora. A women was hit by lightning just north of Denver. A house in the area was also struck.

In 1985…a thunderstorm produced strong wind gusts over southern metro Denver. One strong wind gust hit Cheery Creek Reservoir…capsizing a boat and drowning a man. The wind gusts…clocked as high as 50 mph…also downed a few trees.

In 1989…1 3/4 inch diameter hail fell at Intercanyon in the foothills of Jefferson County.

In 1990…lightning caused minor damage to a south Aurora home. No injuries were reported.

In 1994…strong thunderstorm winds caused damage in southern weld County near Hudson and Fort Lupton. Two mobile homes were destroyed and a few lost their roofs. Up to 20 downed power poles and the destruction of two 115 thousand-volt towers caused widespread power outages. Thunderstorm gust front winds from the north gusted to 48 mph at Stapleton International Airport.

In 2000…lightning ripped most of the roof from a home in southeast Aurora. The bolt sparked a fire which destroyed the residence. Damage was estimated at 250 thousand dollars.

In 2002…the temperature climbed to a maximum of 100 degrees setting a new record high for the date.

In 2003…a teenager was injured when he was struck by lightning while camping at Herman Lake…13 miles northwest of Georgetown. The boy was knocked unconscious and suffered minor injuries.

In 2013…a dry microburst uprooted 30 to 40 large trees across a 12-block area of the Park Hill neighborhood in east central Denver. Several trees were snapped near the base along with numerous branches…8 to 10 inches in diameter. Power poles and lines were also downed with resulted in outages which affected seven hundred residents. One of the downed trees crushed a car`s hood… narrowly missing the driver. At Denver International Airport…a peak wind gust of 22 mph was observed from the southwest.


In 1979…heavy thunderstorm rains on each of 4 consecutive days dumped a total of 2.62 inches of rain on Stapleton International Airport. The heaviest rain…1.05 inches… On the 19th was accompanied by 1/4 inch diameter hail.

» Click here to read the rest of August 14 to August 20: This week in Denver weather history

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Seasonal temps, a better chance for storms Thursday

Thursday, August 18th, 2016 5:18am MDT

A pretty significant change in the overall weather pattern begins to take place today. While Thursday will remain warm, by the end of the day conditions become unsettled and the coming days will offer much cooler conditions.

For today we start with sunny skies. By mid-morning cloud cover will be increasing and heading towards partly sunny skies in the mid to late afternoon. Temperatures will be maxing out right around the average for the date of 87 degrees.

We do expect to see some isolated thunderstorm and shower activity but later than usual. Best chances come after about 5:00pm and will continue until midnight.

Previewing the coming days, a low pressure trough will pass tomorrow and with it bring cooler temperatures. Highs Friday and Saturday look to be in the mid-70s before warming back up to the 80s Sunday. We’ll have good chances for storms and showers tomorrow into tomorrow night. More details in the extended forecast here.

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Homes burn, thousands flee as fire chars 30,000 acres in Southern California’s Cajon Pass

Wednesday, August 17th, 2016 6:25pm MDT

LYTLE CREEK, Calif. — An explosive brush fire that has ripped through more than 30,000 acres of hills, canyons and flatlands in Southern California’s Cajon Pass has bewildered veteran firefighters who fear the flames will only worsen. “It hit hard, it hit fast — it hit with an intensity that we haven’t seen before,” San Bernardino… » Click here to read the rest of Homes burn, thousands flee as fire chars 30,000 acres in Southern California’s Cajon Pass

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