Thornton, Colorado, USA
UpdatedFri, 28-Apr-2017 2:10am MDT 


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Thornton’s Thursday keeps things cool, cloudy and maybe a bit wet

Thursday, April 27th, 2017 5:05am MDT

Our next weather system is pushing into the state this morning and will keep conditions unsettled today. Temperatures will be below normal and we may see periods with rain.

We start out mostly cloudy and will remain so through the morning. This afternoon and evening will bring a bit of clearing but still with a good number of clouds.

Temperatures will be chilly to start then head toward a high in the mid to upper 50s, a ways below the average for the date of 65 degrees.

We’ll see chances for showers throughout the day with the best opportunity coming from about mid-morning through the noon hour. This afternoon we may see a bit of thunder mixed in. Shower activity will diminish by late afternoon and evening.

Tonight will see partly clear skies and lows in the low to mid-30s.

Use our interactive radar to keep an eye on any showers in the area.

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The sun and dry conditions return briefly on Wednesday

Wednesday, April 26th, 2017 5:16am MDT

We find ourselves between two systems today giving us a brief period with the sun and drier conditions. It will be short-lived however as showers return later today and conditions become more unsettled through the rest of the week.

We start out today with mostly sunny skies and should see a good dose of sun until mid-afternoon or so when cloud cover increases. Temperatures start out cold and below freezing but then will warm up to a high near 60 degrees. That is comfortable but a few degrees below normal.

Some scattered shower activity will be possible from about 2:00pm and lasting through tonight and tomorrow. At this time we’re not expecting much precipitation overall however.

Tonight lows will dip to the upper 30s.

Looking ahead, Thursday and Friday have the potential to be a bit damp with varying levels of shower activity. The main focus is on what happens Friday night into Saturday morning. It is a good ways out and too far to put any numbers out but we do see the potential for accumulating snowfall.

Check current conditions with our live gauges here.

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Video: Former Obama admin official says climate agencies purposely mislead

Tuesday, April 25th, 2017 7:32am MDT

A fascinating insider look from a scientist about how our nation’s government agencies spin data to push their agenda.

Former Energy Department Undersecretary Steven Koonin: “What you saw coming out of the press releases about climate data, climate analysis was, I would say, misleading, sometimes just wrong…”

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Weather conditions turn cooler, become unsettled for Tuesday

Tuesday, April 25th, 2017 5:12am MDT

As promised, a change in the weather pattern has arrived as the first in a series of fronts moves through. This one will bring us cooler temperatures today, a chance for showers later and perhaps even a bit of snow overnight.

We start out the day with mostly cloudy skies and can expect more of the same throughout the daytime hours. Winds will initially be calm but by mid-afternoon they will shift out of the north and become gusty through the evening and into the first part of tonight. Temperatures today will be climbing to a high in the mid-50s, a good ways below the average for the date of 64 degrees.

Moisture will be increasing as the day progresses and we begin to see a slight chance for showers and thunderstorms after noon with the best chances occurring from about 4:00pm to 9:00pm. After 9:00pm, things will have cooled off enough that we may see some snow fall although at this time we are not expecting any accumulation.

Precipitation should end in the early morning hours tomorrow and overnight lows will dip to right near freezing.

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April 23 to April 29: This week in Denver weather history

Tuesday, April 25th, 2017 5:02am MDT
This Week In Denver Weather History

April 23 to April 29: This week in Denver weather history

Certainly April can bring pleasant weather but it also can bring thunderstorms and even heavy, damaging snow as we see in our look back at this week in Denver weather history.

From the National Weather Service:


In 1989…unusually warm weather resulted in several daily temperature records being broken in Denver. The high temperature of 89 degrees on the 21st exceeded the record maximum for the month at that time. Daily record high temperatures were either exceeded or equaled with 83 degrees on the 20th…88 degrees on the 22nd…and 85 degrees on the 23rd. The low temperature of 55 degrees on the 22nd equaled the record high minimum for the date.


In 1999…a spring snowstorm dumped heavy snowfall over metro Denver and in the foothills. Nearly 3 feet of snow fell in the foothills with over a foot in the city. The heavy wet snow downed power lines in Douglas and Elbert counties. Scattered outages were reported at Parker…Franktown… Sedalia…and Castle Rock. Some residents were without electricity for as long as 20 hours. The inclement weather was blamed…at least in part…for several traffic accidents along the I-25 corridor between Denver and Castle Rock. Snowfall totals included: 32 inches at Idaho Springs; 31 inches on Crow Hill; 29 inches near Evergreen; 26 inches at Chief Hosa and Coal Creek Canyon; 25 inches at Bailey; 24 inches at Floyd Hill; 23 inches at conifer…Genesee…Golden Gate Canyon…North Turkey Creek…and Pine Junction; 13 inches at Broomfield and near Sedalia; 12 inches in Boulder; 11 inches at Louisville and Parker; and 9 inches at the site of the former Stapleton International Airport.

In 2004…heavy snow fell across metro Denver…when low level upslope conditions developed against the foothills and Palmer Divide. Snowfall totals included: 18 inches in the foothills southwest of Boulder…17 inches at Intercanyon and near Conifer…10 inches near Blackhawk and Parker…9 inches at Castle Rock and near Sedalia…7 inches in Centennial… Littleton…and near Lone Tree. Elsewhere across metro Denver…snowfall generally ranged from 2 to 5 inches. Snowfall was 4.7 inches at Denver Stapleton. Northwest winds gusted to 35 mph at Denver International Airport on the 21st.


In 1885…the worst snow storm since station records began in 1872 dumped a total of 24.0 inches of snowfall on the city. The 23.0 inches of snow recorded on the 22nd and 23rd was the greatest 24-hour snowfall ever recorded during the month of April. Streets were impassable…roofs caved in… Telegraph and telephone wires were downed…railroads were blocked and trains delayed…and most business came to a complete standstill. Estimated losses were reported to 50 thousand dollars. The total snowfall was partly estimated due to melting. Precipitation from the storm totaled 2.79 inches.

In 1915…post-frontal rain during the day and overnight totaled 2.00 inches. Most of the rain fell on the 22nd.

In 1945…6.7 inches of snow fell over downtown Denver. This was the third major snow in a little over 3 weeks…which made this month the 4th snowiest on record. Northeast winds were sustained to 25 mph and light hail fell on the 22nd.

In 2013…a spring storm brought heavy snow to the mountains… with period of moderate to heavy snow to portions of the Front Range Foothills and Urban Corridor. In the mountains and foothills…storm totals included: 18 inches at Niwot Ridge SNOTEL; 16.5 inches near Ward; 13 inches at Arapahoe Basin and Roach SNOTEL…12 inches near Blackhawk; 11.5 inches near Nederland; 11 inches near Allenspark and at Loveland Ski Area; 10 inches near Idaho Springs and Pinecliffe; with 9.5 inches and near Silverthorne. Along the Urban Corridor storm totals included: 7.5 inches near Morrison; 7 inches at the National Weather Service Office in Boulder and Niwot; 6.5 inches near Arapahoe Park and Superior; with 6 inches at Lafayette and Lakewood. At Denver International Airport…4.7 inches of new snowfall was observed.


In 2010…a potent spring storm brought heavy…wet snow to areas in and near the Front Range foothills and widespread rainfall across the adjacent plains. In the Front Range foothills and north-central mountains east of the Continental Divide…storm totals ranged from 15 to 30 inches. Storm totals included: 29.5 inches…3 miles southeast of Pinecliffe; 27 inches…8 miles northeast of four corners; 23 inches at Willow Creek; 22.5 inches… 13 miles northwest of Golden; 21 inches at Never Summer; 17 inches at Eldorado Springs; 16.5 inches…3 miles west of Jamestown. Denver International Airport reported just a trace of snowfall…but measured 2.01 inches of rainfall for the duration of the storm. In addition…a peak wind gust to 54 mph from the northwest was observed at the airport on the 23rd


In 1889…north winds were sustained to 48 mph.

In 1913…northeast winds were sustained to 46 mph with gusts to 60 mph behind a dry cold front.

In 1914…a thunderstorm produced considerable hail and 0.29 inch of rain. West winds were sustained to 42 mph with gusts to 48 mph.

In 1942…hail of unknown size fell over the city.

In 1958…a funnel cloud was sighted for 20 minutes…15 miles southeast of Stapleton Airport. The funnel formed in advance of a thunderstorm and hung about a thousand feet below the base of the cloud…but remained aloft. Later in the day…3.6 inches of snow fell at Stapleton Airport.

In 2002…persistent dry conditions in the foothills contributed to the first large forest fire of the season near Bailey. Very dry and windy conditions allowed the fire…initially started by a careless smoker…to grow into a 2400-acre blaze before it could be contained. Fortunately…no significant damage occurred to homes or other property in the area.

In 2006…severe thunderstorms produced large hail across metro Denver. Hail as large as 1.25 inches in diameter fell in south Denver with hail to 0.88 inch across the rest of the city. Hail to 1.00 inch in diameter was reported near Morrison…in south Lakewood…and in Aurora near Cherry Creek. Hail to 0.88 inch was measured in Golden with 0.75 inch hail in east Lakewood.

» Click here to read the rest of April 23 to April 29: This week in Denver weather history

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Former Obama Official Says Bureaucrats Manipulate Climate Stats to Influence Policy

Tuesday, April 25th, 2017 3:23am MDT

A former member of the Obama administration claims Washington D.C. often uses “misleading” news releases about climate data to influence public opinion. Former Energy Department Undersecretary Steven Koonin told The Wall Street Journal Monday that bureaucrats within former President Barack Obama’s administration spun scientific data to manipulate public opinion. “What you saw coming out of the… » Click here to read the rest of Former Obama Official Says Bureaucrats Manipulate Climate Stats to Influence Policy

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Thornton to enjoy a mild Monday, by the end of the day, signs of change

Monday, April 24th, 2017 5:42am MDT

Today will be the last unseasonably warm day of the week. In fact, by tonight we should start feeling the effects of the first of a series of systems that will bring cooler, unsettled weather through the weekend.

For today we start out with mostly sunny skies then will see a slow buildup of cloud cover leading to mostly cloudy skies by the evening. Temperatures will be warming up to a pleasant high right near the 70 degree mark.

This evening we see a slight chance for thunderstorms then similar chances for overnight showers. We aren’t expecting much in the way of precipitation however. Overnight lows tonight will be dipping to the low to mid-40s.

For the balance of the week, a series of three storm systems coupled with cold fronts will usher in cooler temperatures and varying chances of precipitation. We may even be seeing some early morning snow on a couple of days. Get more details in the extended forecast here.

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April 2017 top shots: Monthly photo slideshow

Sunday, April 23rd, 2017 6:08pm MDT
An American Kestrel enjoys a warm, early April day at the Rocky Mountain Arsenal. (Shawn Jones)

An American Kestrel enjoys a warm, early April day at the Rocky Mountain Arsenal. (Shawn Jones)

April can be a tricky month weather-wise with everything from mild temperatures to snow to severe weather being possible.  The good thing about that is that it provides plenty of chances for great photos!

April marks a transition between winter and summer for most of the country but for Denver it is especially true as we can see a stunning variety of weather.

The proverbial April showers are certainly a possibility for Denver. Snow? Tornadoes? Thunderstorms? You bet – all can happen!

Throw in our usual wildlife plus the wide variety of birds that return to the Centennial State for the spring and summer and there is a lot going on.

  • Slideshow updated April 12, 2017. 
  • 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.

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!

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Severe Weather 101 – Severe Weather Awareness Week wrap up

Saturday, April 22nd, 2017 5:10am MDT
Supercell thunderstorms like this can be beautiful - but they can also be deadly. Do you know what to do when severe weather strikes? (Stormscape Photography / FLICKR)

Supercell thunderstorms like this can be beautiful – but they can also be deadly. Do you know what to do when severe weather strikes? (Stormscape Photography / FLICKR)

Over the past week we have highlighted some of the severe weather hazards that we face in Colorado every spring and summer in our Severe Weather 101 series.  The dangers these present are significant and not to be taken lightly.

Tornadoes grab most of the headlines and certainly are a danger however others like lightning and flooding are more common and actually claim more lives.  We ask all of our readers to please, take the time to review these important articles – they could save yours and your family’s lives!

The National Weather Service has published a nice wrap up of Severe Weather Awareness Week that covers all the basics – see it below.  For more in depth information, please use the links at the bottom to view each article on our Severe Weather 101 series.  Be safe and be weatherwise!

600 AM MDT SAT APR 22 2017


Severe Weather Awareness Week in review…

Severe Weather Awareness Week in Colorado concludes today. During the past week we have presented information and safety rules for tornadoes, lightning and wildfires, floods and flash floods, straight-line thunderstorm winds, hail, and our warning programs.

We will now review some of the most important safety rules in our effort to build a Weather-Ready Nation.

Be weather-wise by staying informed on expected weather in your area. The National Weather Service is typically aware of the potential for severe weather many hours or even days before any severe weather watches or warnings are issued, providing forecast products to heighten your awareness. A Weather Story product is posted each day on National Weather Service Internet pages and Facebook pages which includes a map and text on possible hazardous weather expected within the next seven days.

A Hazardous Weather Outlook is also issued daily with information on possible hazardous weather through the next seven days. A watch is issued when conditions for severe weather or flooding become possible. A warning is then issued when life threatening conditions are imminent or occurring.


Tornadoes can even strike in mountain areas. In 2008 on August 23rd, this rope tornado struck Park County near Eleven Mile Reservoir. Image courtesy Jerry Bivens.

Tornadoes can even strike in mountain areas. In 2008 on August 23rd, this rope tornado struck Park County near Eleven Mile Reservoir. Image courtesy Jerry Bivens.

The best way to protect yourself from tornadoes is to have a plan of action. The safest place to be if a tornado approaches is in a basement or safe room within a well-built structure, or in an underground storm shelter. If none of these options are available, move to a hallway or a small interior room on the lowest floor, usually this is a closet or bathroom. Get under a heavy piece of furniture or in a bath tub and cover yourself with blankets. Remember, the greatest risk of injury from tornadoes is from flying debris.

Modular homes and mobile homes, even those tied down, offer little protection from tornadoes. If a tornado approaches, leave those locations and seek safety in a nearby sturdy building or storm shelter.

If you are driving in open country and see a tornado, if time permits, the best thing to do is simply drive away from the tornado path. Do not take shelter beneath a highway overpass. Wind speeds may actually be higher in these areas and often become collection points for debris.

If you are caught outside and cannot seek shelter inside a sturdy structure, crawl into a culvert or lie down in a narrow ditch or ravine and cover your head. But remember that the worst place to be when a tornado threatens is outside in the midst of flying debris.


Lightning usually kills and injures more people in Colorado than any other thunderstorm hazard. Lightning also causes many wildfires.

The best defense to protect yourself against a lightning strike is to plan ahead and avoid being caught where you might be vulnerable. Check weather forecasts prior to venturing out, especially if you are heading into the mountains. Plan outdoor activities early in the day before storms develop.

If thunderstorms threaten, seek shelter in a building or in an enclosed metal-roof vehicle, making sure all windows and doors are closed. Never seek shelter under an isolated tree. During thunderstorms, stay off corded telephones, away from electrical devices, and away from plumbing. Also get out of shower stalls, bath tubs, swimming pools and lakes when lightning is nearby.

You should wait at least 30 minutes after the last sound of thunder before resuming outdoor activities. When thunder roars…go indoors.

Floods and Flash Floods

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

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

When flooding or flash flooding is possible, you should remain alert and be ready to quickly evacuate to higher ground or climb to safety. Flash floods often occur suddenly and without warning. You need to follow some basic flood safety rules:

  • Do not camp or park your vehicle along streams and washes, particularly during threatening conditions.
  • If you are near a river, be aware of water levels and be prepared to move to higher ground if river levels rise.
  • Do not enter areas that are already flooded.
  • If walking or fishing along a river, be aware that erosion from swift running water can cause river banks to collapse.
  • Never let your children play around high water, storm drains, viaducts or arroyos.

At least half of all flash flood fatalities are vehicle related. While driving your automobile, look out for flooding at highway dips, bridges and low areas. Two feet of moving water will carry away most vehicles. Never attempt to drive across a flooded road. And be especially cautious at night when it is difficult to see flood dangers.

Strong Straight-Line Winds

Straight-line winds from thunderstorms, including microbursts, can become quite strong, even reaching speeds in excess of 100 mph in extreme cases. When thunderstorms approach, high winds can suddenly develop, causing things on the ground to become swift moving airborne missiles with a potential force to injure or kill. As with any thunderstorm, seek shelter before the storm arrives.


This is one of the largest recorded hail stones which is more than 7 inches in diameter and fell in Nebraska in 2003. (NOAA)

This is one of the largest recorded hail stones which is more than 7 inches in diameter and fell in Nebraska in 2003. (NOAA)

Large hail can pose a danger to animals and people. Hail also produces considerable damage to crops and personal property each year in Colorado. Again, get indoors before thunderstorms arrive. A fall of small hail can suddenly change to a fall of very large ice missiles which can injure or kill. Make efforts to protect personal property before storms threaten.

Warning Notification

When thunderstorms threaten, tune to NOAA All-Hazards Weather Radio, The Weather Channel, or your local radio or television stations. Also check the Internet web site from the National Weather Service office serving your area. And if you have a relatively new cell phone you should receive Tornado and Flash Flood Warnings on your phone if you are in the area of the warning.

During threatening weather days, plan the actions you will need to take so that you will be prepared if dangerous weather conditions actually develop.

NOAA’s National Weather Service wishes you a safe severe weather season.

Severe Weather Awareness Week in Colorado concludes today. During the past week we have presented information and safety rules for tornadoes, lightning and wildfires, floods and flash floods, straight-line thunderstorm winds, hail, and our warning programs.


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Severe Weather 101 – Lightning and lightning safety

Friday, April 21st, 2017 5:08am MDT
This is NOT the time to be outside. (michaeljames / FLICKR)

This is NOT the time to be outside. (michaeljames / FLICKR)

Of all the weather types associated with thunderstorms – hail, tornadoes, floods, etc – lightning is usually the most dangerous. In the United States there are an estimated 25 million cloud to ground lightning flashes each year and each one is a potential threat to life and property.

During the past 10 years there has been an annual average of 39 lightning fatalities in the United States. Last year, 23 people lost their lives due to lightning.

Colorado is ranked # 2 in lightning related deaths (2001 – 2010) so the danger this presents to life and property is very significant for us. It is interesting to note though that Colorado ranks only 32nd in the number of cloud to ground strikes over that same period. Which means, in short, we have fewer strikes than many other states and yet more deaths.

This highlights the fact that, quite frankly, folks here in Colorado are not aware of the dangers lightning presents and they do not take proper steps to protect themselves. One of the great things about Colorado are the outdoor activities we all enjoy, but there comes a time when we need to head indoors.

» Click here to read the rest of Severe Weather 101 – Lightning and lightning safety

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