63°F
Thornton, Colorado, USA
UpdatedThu, 07-Jul-2022 12:40am MDT 
 

Navigation

ThorntonWeather.com on Twitter

ThorntonWeather.com on Facebook

 

Weather Geek Stuff - weathergeekstuff.com

Rocky Mountain Weather Network

Tony's Takes Photography

ThorntonWeather.com

Recent News and Posts


Severe Weather 101 – Hail and Wind

Thursday, April 14th, 2022 5:00am MDT
Straight line winds can be as damaging as a tornado. This image is from a park in Tennessee. (NWS)

Straight line winds can be as damaging as a tornado. This image is from a park in Tennessee. (NWS)

During the spring and summer months in Colorado, a wide array of severe weather can strike. Tornadoes may grab all the headlines, but straight line winds and hail can do a great amount of damage in their own right – and they are more common.

Straight line winds are winds out of a thunderstorm and are classified as severe when they hit 58 mph. These winds can reach tornado and hurricane force and as a result, cause property damage and can injure and even kill animals and humans.

These winds are usually the result of air cooling rapidly due to precipitation or evaporation. As the cooler air is heavier than the surrounding warmer air, it rushes downward, accelerating toward the ground and spreads out as it hits, much like pancake batter being poured onto a griddle.

» Click here to read the rest of Severe Weather 101 – Hail and Wind

Join the Discussion - Post your commentJoin the Discussion!

Denver sets low temperature record for April 13

Wednesday, April 13th, 2022 6:40am MDT

Record Cold Temperatures

There was definitely a chill in the air this morning and the data shows it was record-setting.

As measured at Denver International Airport, the official low for the Mile High City hit 10 degrees this morning. This easily bests the previous record low for the date of 15 degrees set just two years ago in 2020.

Here in Thornton, we weren’t quite as cold with a low of 13 degrees.

We will warm up some today but temperatures will remain well below normal and we will again be dealing with blustery winds.

Join the Discussion - Post your commentJoin the Discussion!

Chilly, blustery weather conditions for Thornton’s Wednesday

Wednesday, April 13th, 2022 5:06am MDT

Not exactly a great forecast for us today. Temperatures are going to be well below normal and we again will have a healthy dose of wind.

Mostly sunny skies will be above today with a few more clouds later. High temperatures will top out only in the mid-40s. Winds will be light initially then quickly ramp up by mid to late morning. The wind coupled with cool temps will not make it very pleasant outside.

Tonight, winds will ease in the evening and become calm closer to midnight. Skies will gradually clear with overnight lows near 20 degrees.

Join the Discussion - Post your commentJoin the Discussion!

Severe Weather 101 – Floods and Flash Floods

Wednesday, April 13th, 2022 5:05am MDT
The Big Thompson Flood in 1976 claimed the lives of 144 Coloradoans and serves to remind us of the dangers of floods.

The Big Thompson Flood in 1976 claimed the lives of 144 Coloradoans and serves to remind us of the dangers of floods.

For much of Colorado, floods and flash floods present a grave danger to life and property. These usually are the result of one of two things – spring snow melt occurring rapidly or a severe thunderstorm. Colorado is very susceptible to flash flooding and these occur somewhere every year in the state.

The waters from flash floods can move with extraordinary speed and strike with little or not warning.  Their force can be extremely destructive and when coupled with trees, dirt, rocks and other debris they carry downstream, they are deadly.

Flooding is the number one weather killer in the United States.

» Click here to read the rest of Severe Weather 101 – Floods and Flash Floods

Join the Discussion - Post your commentJoin the Discussion!

Cooler temps, a chance for showers and, yes, wind for Tuesday

Tuesday, April 12th, 2022 5:10am MDT

Our weather takes a cooler turn today with a return of some blustery winds. While we do stand a chance to see some precipitation, any that falls looks to be minimal.

Partly to mostly cloudy skies will be above throughout the daytime hours. High temperatures will top out in the low 50s. Winds will be picking up this morning and remain blustery throughout. There will be the potential for some scattered shower activity, perhaps even with a few snowflakes in the late afternoon and evening.

Tonight, winds will slowly easy. Skies will remain partly clear and lows will be dropping to the low 20s.

Join the Discussion - Post your commentJoin the Discussion!

Severe Weather 101 – Tornadoes and tornado safety

Tuesday, April 12th, 2022 5:00am MDT
Last year's Windsor Tornado highlights the very real danger twisters present in Colorado. Do you know when to do when one strikes?

The 2008 Windsor Tornado highlights the very real danger twisters present in Colorado. Do you know when to do when one strikes?

One fact that may surprise those new to Colorado is that we are actually on the western edge of the infamous Tornado Alley. This large swath of land comprises much of the nation’s midsection and is a unique place as the United States sees more tornadoes than any other place on earth. In fact, tornadoes have been recorded in all 50 states including Alaska and Hawaii.

Closer to home, Colorado sees our share of these storms. In fact, one metro area county – Weld County – holds the distinction of being the “tornado capital of the world.” With 252 tornados from 1950-2011, no single county in the nation has had more tornadoes! Adams County is number two in the state and isn’t far behind with 156 over that same period.  Granted these numbers are skewed a bit simply due to the sheer size of those counties, but it does serve to highlight the real danger that tornadoes present.

Even here in the metro area tornadoes are a real danger. The Thornton area was struck in 1981, one of the worst tornadoes to strike the Denver area in history. At 2:30 p.m. this tornado touched down and by 2:45 p.m., the tornado had hit Thornton City Hall. The tornado’s destruction sent 53 injured people to hospitals, 25 homes were destroyed and 239 structures were damaged.

One common myth is that tornadoes don't strike metropolitan areas. This has been disproved many times including here in Colorado in 1982 when an F2 tornado struck Thornton. Image courtesy the City of Thornton archives.

One common myth is that tornadoes don’t strike metropolitan areas. This has been disproved many times including here in Colorado in 1981 when an F2 tornado struck Thornton. Image courtesy the City of Thornton archives.

The most well known tornado outbreak in the metro area occurred on June 15, 1988. Five tornadoes resulted in seven injuries and damage in excess of $15 million.

We all of course also remember in 2008 when the town of Windsor, not far from Denver, was struck with an EF-3 tornado that claimed one life and destroyed and damaged hundreds of buildings.

The greatest threat for tornadoes occurs during late spring and early summer when you have a combination of heat and moisture in the lower atmosphere. Here in Colorado, tornadoes are frequent from May through August with June being the most active month.

However, there is no hard and fast rule for when tornadoes strike, as Colorado witnessed on March 29, 2007 when Holly, Colorado was struck by an EF-3 tornado with winds of 165 mph. Two women lost their lives as a result of that event and 160 homes were damaged.

Colorado ranks 10th in terms of the number of tornadoes with 1,911 events from 1950-2011. One good thing is that our high altitude and drier air do make it harder for the monster supercells that spawn the biggest tornadoes to form. Most of our tornadoes are small and short lived. Further, thanks to the wide open spaces of the eastern half of our state, many strike sparsely populated areas. This is reflected in the fact that we rank 38th for tornado related deaths.

» Click here to read the rest of Severe Weather 101 – Tornadoes and tornado safety

Join the Discussion - Post your commentJoin the Discussion!

Thornton’s workweek starts off with temps near normal, some breezy winds

Monday, April 11th, 2022 5:00am MDT

Not too bad of a way to start the workweek. We will see temps a bit above average but with some cloud cover and breezy winds.

Partly sunny skies will be above throughout the daytime hours. Winds will be light initially then this afternoon become a bit breezy, but nowhere near on the level of what we saw yesterday and last week. High temperatures will top out in the low to mid-60s.

Tonight, skies will be partly cloudy with overnight lows in the low 40s.

Join the Discussion - Post your commentJoin the Discussion!

Severe Weather 101 – Watches, Warnings and More

Monday, April 11th, 2022 5:00am MDT
Last year's Windsor tornado highlighted just how dangerous weather in Colorado can be. Are you and your family prepared? Do you know what the watches and warnings all mean?

The 2008 Windsor tornado highlighted just how dangerous weather in Colorado can be. Are you and your family prepared? Do you know what the watches and warnings all mean?

We’ve all seen TV or Internet news of a weather related watch or warning being issued. But, how many really know what they mean? There is a pretty big difference between the two and it is important to be aware just what it means to you so you can take the appropriate precautions.

Dozens of weather related fatalities occur every year in Colorado, many simply out of ignorance. Taking the time to be aware of the conditions around you and taking appropriate action will keep you from becoming a statistic.

Naturally you can get information on current advisories from television as local stations usually do a good job of “crawling” them on the screen when they are issued. This works well if you have a TV available but if not, the radio would be a secondary source. The Internet and the National Weather Service’s website are a great one when at a computer.

The problem with relying on news media or the Internet is that their ability to warn you of a developing weather situation is dependent on your monitoring them.  Severe weather can strike without little warning.  How will you know if severe weather is about to strike if you don’t have the TV or radio on?

Your first line of defense – NOAA All Hazards Radio

NOAA Weather RadioFor just about anywhere, a special radio that picks up the NOAA’s All Hazard Radio broadcasts is the way to go and provides information from the source. Oftentimes simply called a weather radio, we highly recommend every household have one of these.

These radios are relatively inexpensive and allow you to be immediately notified of official National Weather Service warnings, watches, and forecasts as well as other hazard information like earthquakes, avalanches, chemical spills, and even AMBER alerts.  In fact, with these radios, you will be notified at the exact same time the news media is made aware giving you a head start on preparing for a developing situation.

To learn more about these devices and what you should look for when buying one, click here.

A high-tech alternative – Cell phone weather apps

Many people now have smartphones that allow for downloadable apps and weather-related ones are among the most popular.

All of these applications have a number of weather related features in common.  All provide current conditions for either the location the user is in now or for saved locations and all provide some sort of radar.

Most can be configured to sound an alert when the National Weather Service issues a watch or warning.  While they are no substitue for a weather radio, these apps provide you with immediate notification no matter where you are at.

For a look at some of these weather apps and their features, click here.

» Click here to read the rest of Severe Weather 101 – Watches, Warnings and More

Join the Discussion - Post your commentJoin the Discussion!

April 10 to April 16: This Week in Denver Weather History

Sunday, April 10th, 2022 5:01am MDT

This Week in Denver Weather History

April can be a very eventful weather month and we see that in our look back at this week in Denver weather history. Particularly notable are many major snow events including two in recent history – one in 2001 and another in 2005.

From the National Weather Service:

7-12

In 1959…snow falling over a 5-day period totaled 20 to 30 inches just east of the mountains…while over the plains blizzard conditions closed schools and blocked highways. The second big storm in two weeks dumped 16.4 inches of snowfall on Stapleton Airport with the most…11.6 inches… Occurring on the 8th. East winds gusted to 37 mph on the 9th. Temperatures dipped into the single digits on the mornings of the 7th and 12th when 7 degrees were registered. Low temperature records for the dates were set on the 9th…10th…and 12th. The cold temperatures caused streets to glaze with ice…resulting in the death of a pedestrian who was struck by a car in Denver. Three people died from heart attacks while shoveling the heavy… Wet snow.

8-10

In 1999…a windstorm caused 20 million dollars in damage along the Front Range urban corridor from Fort Collins south to pueblo and to the east over the plains…making the storm equal to the costliest windstorm ever…which occurred in Boulder on January 17…1982. In metro Denver… Several homes were damaged as shingles were blown off roofs. Large pieces of a roof torn off a strip mall in Lakewood damaged several cars in a parking lot. Most of the damage to homes consisted of broken fences…awnings…doors…and windows. Scores of automobiles suffered broken or cracked windshields and paint damage from flying debris. Multiple accidents were triggered as several tractor-trailer rigs were blown on their sides by the strong cross-winds. Blowing dust and dirt caused near zero visibilities at times. Both I-25 and I-76 were closed north and northeast of Denver. State Highway 93 was closed between Golden and Boulder. Several trees…power poles…and power lines were downed…causing a number of outages as well as sparking a few small grass fires. Highest wind gusts reached 112 mph atop Niwot Ridge near the continental divide west of Boulder…102 mph at Wondervu…100 mph at the National Center for Atmospheric Research mesa lab in Boulder…98 mph at the national wind technology center near Broomfield…96 mph on Rocky Flats…92 mph at Jefferson County Airport near Broomfield and on the University of Colorado campus in Boulder…and 90 mph at Highlands Ranch in southwest metro Denver. Winds gusted to 48 mph at Denver International Airport.

9-10

In 1900…rain changed to heavy snow and totaled 6.8 inches in downtown Denver overnight. A thunderstorm occurred on the 9th. North winds were sustained to 32 mph with gusts to 38 mph on the 10th. Precipitation totaled 1.39 inches.

In 1933…post-frontal heavy snowfall totaled 9.4 inches in downtown Denver. East winds were sustained to 21 mph with gusts to 22 mph on the 9th.

In 1944…7.0 inches of snow fell on downtown Denver. Northeast winds were sustained to 24 mph on the 9th.

In 1977…the two warmest days of the month resulted in two temperature records being set. High temperature of 81 degrees on the 9th set a new record maximum for the date. High temperature of 80 degrees on the 10th equaled the record maximum for the date. The unusually warm weather for so early in April produced a late afternoon thunderstorm on the 10th.

In 1993…strong downslope winds occurred along the Front Range. While the strongest winds were in the foothills north of Denver…wind gusts to 69 mph were recorded at Jefferson County Airport in Broomfield. Northwest winds gusted to 39 mph at Stapleton International Airport.

In 2004…a spring storm brought heavy snow to metro Denver. The heaviest snow fell in the foothills and over and near higher terrain. Snowfall totals included: 20 inches near Jamestown; 18 inches atop gold hill; 17 inches near Evergreen; 15 inches at Nederland and Eldora; 13 inches at Blackhawk; 11 inches at Aspen Springs; 9 inches in Louisville; 8 inches at Ken Caryl; 6 inches at Niwot… Near Sedalia…and in Thornton; 5 inches in Lakewood… Lyons…and Westminster. Snowfall was 4.4 inches at Denver Stapleton. Northwest winds gusted to 21 mph at Denver International Airport.

In 2008…a very moist storm brought heavy snow to parts of the Front Range foothills. Storm totals included: 12.5 inches at Aspen Springs…11 inches…4 miles west- southwest of conifer; with 10.5 inches…3 miles north of central city and 6 miles southwest of Evergreen. Lesser amounts of 5 to 9 inches were observed elsewhere. North winds gusted to 43 mph at Denver International Airport on the 10th…and 1.8 inches of snow fell at the former Stapleton International Airport.

9-11

In 1951…heavy snowfall totaled 9.4 inches at Stapleton Airport. The storm was accompanied by strong northeast winds gusting to 43 mph.

In 1953…heavy snowfall occurred at Stapleton Airport where 7.9 inches of snow were measured. North winds gusted to 29 mph.

In 1994…6 to 14 inches of heavy snow buried much of eastern Colorado…closing many schools and I-70 from east of Denver to the Kansas border. Rain changed to snow on the 9th…and snow continued through the 11th. Snowfall totaled 5.7 inches at Stapleton International Airport…but maximum snow depth on the ground was only 3 inches on the 10th due to melting. East winds gusted to 26 mph on the 9th.

In 1995…a major spring storm dumped 8 to 16 inches of snow in the foothills west of Denver. Snowfall totaled 8.3 inches at the site of the former Stapleton International Airport…but most of the snow melted as it fell with the maximum snow depth on the ground of only 2 inches. Five-to 6-inch snow accumulations occurred over southern portions of metro Denver and eastward onto the plains. Northeast winds gusted to 36 mph at Denver International Airport on the 10th. I-70 was closed for several hours east of Watkins to the Kansas border due to drifting snow and near whiteout conditions. High temperature of only 29 degrees on the 10th was a record low maximum for the date.

9-12

In 1901…rain changed to snow and totaled 10.8 inches in downtown Denver over the 4 days. Northeast winds were sustained to 28 mph with gusts to 31 mph on the 11th. Temperatures hovered in the 30’s.
10

In 1896…southwest winds were sustained to 40 mph with gusts to 60 mph. The apparent Chinook winds warmed the temperature to a high of 76 degrees.

In 1899…northwest Chinook winds were sustained to 45 mph with gusts as high as 60 mph. The downslope winds warmed the temperature to a high of 73 degrees in the city.

10-11

In 1979…a heavy snow storm produced near-blizzard conditions across eastern Colorado with 10 to 20 inches in the foothills and 4 to 8 inches over the plains. Winds to 35 mph combined with the snow to produce drifts at least 3 feet deep…closing many roads and causing power outages. Travel was interrupted south of Denver when the storm closed both I-25 and State Highway 83. Snowfall totaled only 3.8 inches at Stapleton International Airport where northeast winds gusted 37 mph…causing some blowing snow on the 11th.

In 2001…a potent spring storm dumped heavy snow over metro Denver and the adjacent foothills…while a blizzard roared across the plains to the east of Denver. Snowfall amounts ranged up to a foot and a half across metro Denver and in the foothills. North to northwest winds at sustained speeds of 40 to 50 mph with gusts as high as 60 mph piled the snow into drifts of 3 to 6 feet deep. I-25 southbound was closed at Lincoln Avenue. I-70 to the east was closed at gun club road. The combination of heavy wet snow and damaging winds resulted in widespread electrical outages. Denver International Airport was completely shut down for the first time in its brief 6-year history. Power surges and outages crippled the airport’s massive computer systems. The airport was closed at 5:00 am and did not re-open until mid-afternoon on the 11th. The power outages resulted in businesses and schools closing. Over all of northeastern Colorado…there were 220 thousand customers without power… The worst outage in Xcel Energy’s history. Repairs totaled 1.6 million dollars. Across metro Denver…snow totals included: 18 inches in southeast Aurora…16 inches at centennial airport and Parker…14 inches at Broomfield… 13 inches in Louisville…12 inches at Lakewood and Morrison… 11 inches at Ken Caryl and Thornton…10 inches at the site of the former Stapleton International Airport and in Wheat Ridge…9 inches in Westminster…and 8 inches in Littleton. Thunderstorms preceded the start of the snow on the afternoon of the 10th and were embedded in the snow storm during the early morning hours of the 11th at Denver International Airport where northwest winds gusted to 60 mph on the 11th. Snow storm totals in the foothills included: 17 inches at Genesee…16 inches at Rollinsville… 14 inches at Intercanyon…13 inches in Coal Creek Canyon and near Evergreen…11 inches at Aspen Springs and Chief Hosa…10 inches at Blackhawk…and 9 inches atop Crow Hill.

In 2005…a strong spring storm produced blizzard conditions in areas to the east of Denver and south of I-76 and near- blizzard conditions across metro Denver. The combination of heavy snow and strong winds forced the closure of Denver International Airport…stranding thousands of travelers. Long stretches of I-25…I-70…and I-76 were also closed due to extensive blowing and drifting snow. Snow amounts ranged from 1 to 2.5 feet in and near the eastern foothills and over the Palmer Divide. Drifts were 2 to 5 feet in depth. Downed power lines caused scattered electrical outages. Storm total snowfall amounts in and near the foothills included: 31 inches near conifer; 27.5 inches in Aspen Springs; 25.5 inches near Sedalia and Blackhawk; 25 inches near Bergen Park and around Genesee; 24.5 inches at pine junction and Roxborough Park; 24 inches southwest of Boulder; 23.5 inches at Ken Caryl; 23 inches atop Crow Hill and near Larkspur…Evergreen…and Nederland; 21 inches at Eldora Ski Area; 18 inches at Eldorado Springs and near Castle Rock; 17 inches near Chatfield Reservoir and Perry Park; and 16 inches near Jamestown. Across the city storm total snow amounts were: 22.5 inches in Aurora; 22 inches at Bennett; 20 inches near Arapahoe park and in centennial… Littleton…and south Denver; 17.5 inches near Bennett; 16 inches in Thornton; 15 inches in Lakewood; 14.5 inches in wheat ridge and near Englewood; 14 inches at lone tree and in Arvada; and 9.9 inches at Denver Stapleton. North winds were sustained from 25 to 35 mph with gusts to 46 mph at Denver International Airport on the 10th.

10-12

In 1997…a pacific storm produced heavy snow on the 10th and the 11th in and near the foothills with 6 to 8 inches at Louisville and turkey creek canyon…5 inches at Morrison… And only 3.5 inches at the site of the former Stapleton International Airport. Northeast winds gusted to 24 mph at Denver International Airport. The storm also brought unseasonably cold weather with 5 new temperature records equaled or broken. Record low temperatures of 8 and 6 occurred on the 11th and 12th. Record low maximum temperatures of 20…19…and 30 occurred on the 10th…11th… And 12th respectively. This was also only the second time on record that the temperature had failed to reach the freezing mark for 3 consecutive days in April.

10-14

In 1927…post-frontal rain on the 10th changed to snow on the 11th and continued through the 14th. Snowfall totaled 8.5 inches from precipitation of 1.28 inches. North winds were sustained to 26 mph with gusts to 29 mph on the 13th.

11

In 1954…strong and gusty southeast winds blew all day. Winds as high as 30 mph with gusts to 50 mph produced some blowing dust at Stapleton Airport.

In 1966…a tornado was sighted in an open area of southeast Denver. Slight wind damage in the area was not directly attributable to the tornado. Later in the day…a pilot reported a funnel cloud 10 miles southwest of Denver. Hail to 1/2 inch in diameter fell at Stapleton International Airport.

In 1984…strong Chinook winds gusted to 72 mph at Rocky Flats south of Boulder; speeds reached 70 mph in both Lakewood and Boulder. At Stapleton International Airport… Northwest wind gusts to 52 mph were recorded.

In 2004…an afternoon cold front produced north winds sustained to 36 mph with gusts to 53 mph at Denver International Airport. Light snowfall was 1.1 inches at Denver Stapleton through the evening.

» Click here to read the rest of April 10 to April 16: This Week in Denver Weather History

Join the Discussion - Post your commentJoin the Discussion!

Severe Weather Awareness Week in Colorado gets started

Sunday, April 10th, 2022 5:00am MDT

In 1981 a tornado ripped through Thornton and caused major damage. Last year, funnel clouds were spotted across much of the area. Image courtesy City of Thornton archives.

As is customary as we get further into spring, this coming week has been proclaimed Severe Weather Awareness Week.  This is an opportunity for the public to get reacquainted with the dangers severe weather presents in Colorado.

Tornadoes, lightning, hail, severe wind and flooding are very real hazards that Coloradans face every year during severe weather season.  It is important that you know what to do to protect you and your family.

Just 12 years ago in what was Denver’s weather story of the year, we suffered through a period of unusually severe weather including a tornado that ripped through the Southlands Mall.

Thirteen years ago on May 22nd an EF3 tornado raced north through Weld and Larimer counties resulting in one fatality near Windsor and causing several injuries and destroyed or heavily damaged hundreds of homes.

And of course in 1981 Thornton was the site of the worst tornado to ever strike the Denver metro area.

Tornadoes may get all the press but other severe weather can be damaging and deadly.

Just eight years ago, late summer flooding caused millions of dollars of damage across northeastern Colorado.  It was 45 years ago that thunderstorms brought a raging torrent of water down the Big Thompson and caused one of Colorado’s worst natural disasters.  Eleven years ago hail struck the Thornton area causing damage to homes and vehicles.

In conjunction with the National Weather Service’s statements on Severe Weather Awareness Week, ThorntonWeather.com will be publishing our Severe Weather 101 series.  Each day this week a weather hazard will be discussed in depth and we will outline protective measures you can take to keep yourself and your family safe.  Please be sure to check back every day to read these important message.

» Click here to read the rest of Severe Weather Awareness Week in Colorado gets started

Join the Discussion - Post your commentJoin the Discussion!