Thornton, Colorado, USA
UpdatedSun, 24-Mar-2019 9:35pm MDT 


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Warmer temperatures, lots of sun for Thornton’s Tuesday

Tuesday, October 16th, 2018 5:05am MDT

Continued improvement in our weather today as the mercury climbs a good bit and we enjoy dry, calm conditions. This is more like what we hope to see in the fall.

The day starts out with clear skies. A few clouds will arrive around noon and be around in the afternoon and evening but they won’t be too intrusive. Overall conditions will be dry and calm. Temperatures start out chilly but then will warm up nicely toward a high in the mid-50s.

Tonight, skies remain mostly clear with lows dipping to around the freezing mark.

Enjoy! If you’re stuck inside, remember you can keep an eye on things with our live webcams here.

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Winter weather – What does that weather warning mean?

Tuesday, October 16th, 2018 4:00am MDT
You have seen and heard the warnings but do you know what they really mean?

You have seen and heard the warnings but do you know what they really mean?

We all are familiar with the crawls on the TV screen or the announcements on the radio for winter weather advisories such as Winter Storm Watch, Blizzard Warning, Freeze Warning and more. But, how many of us really know what those mean? There is very specific criteria the National Weather Service follows in issuing these watches and warnings and there are important differences between all of them.

In this second in a series on Winter Weather Preparedness from the National Weather Service, ThorntonWeather.com helps you understand what all of these mean so you can be better prepared.

600 AM TUE OCT 16 2018

From the National Weather Service:

What does that warning mean?

When a warning is issued during the winter season, will you know what it means, and will you know how to respond? During this Colorado Winter Weather Preparedness Week, please become familiar with our list of potentially life-saving winter weather products.

This statement contains warning and advisory criteria for Colorado east of the continental divide. Criteria west of the divide will be provided today in a separate issuance by the Grand Junction forecast office.


A Hazardous Weather Outlook is issued daily by each National Weather Service office serving Colorado. The outlook provides information on potentially hazardous weather out to 7 days into the future. Also, the Weather Story, a graphic of expected hazardous weather, is posted daily on National Weather Service web sites serving Colorado.

Watches and Warnings

A Winter Storm Watch is issued when hazardous winter storm conditions are possible within the next 3 to 4 days, but the timing, intensity, or occurrence may still be uncertain.

In contrast, a Winter Storm Warning is issued for potentially life-threatening winter storm conditions, such as heavy snowfall or a combination of snowfall and blowing snow, which are likely to occur within the next 1 to 2 days.

Warning criteria for heavy snow is defined by the following amounts.

  • For the mountains – 8 inches of snow accumulation in 12 hours or 12 or more inches in 24 hours.
  • For the lower elevations – 6 inches of snow accumulation in 12 hours or 8 or more inches in 24 hours.

A Blizzard Warning is issued when the following conditions are expected to occur for at least 3 hours:

  • Sustained winds of 35 mph or greater.
  • Considerable falling and/or drifting snow lowering
  • Visibilities to less than a quarter mile.

A high wind warning is issued:

  • Mountains…sustained winds 50 mph or more, or gusts of at least 75 mph.
  • Lower Elevations…sustained winds of 40 mph or more, or gusts of at least 58 mph

A Wind Chill Warning will be issued for the following wind chill temperatures:

  • Mountains…minus 35 degrees Fahrenheit or colder.
  • Lower Elevations…minus 25 degrees Fahrenheit or colder.

A Dust Storm Warning will be issued for the following conditions:

  • Visibility reduced to 1/4 mile or less in blowing dust and sustained winds of 25 mph or greater for at least one hour.


Advisories for winter weather are issued for potentially hazardous conditions which are considered more of a nuisance than a life-threatening situation. However, if caution is not taken the advisory events could become life-threatening

This week is Winter Weather Preparedness Week in Colorado. Public information statements will be issued throughout the week to give safety information and help you know how to respond when winter weather threatens.

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Denver sets record low temperature for October 15

Monday, October 15th, 2018 5:14am MDT

Record Cold TemperaturesWe are set to enjoy a warm up this week but before we do that, Denver set its second record cold temperature reading in the past 24 hours.

Yesterday the Mile High City saw a record low maximum temperature. This morning, the mercury plunged to a new record low for the date.

According to the National Weather Service, Denver’s official low temperature this morning, as measured at Denver International Airport, dipped to 18 degrees.  This set a new record low for the date beating the previous record of 20 degrees set in 1970.

Here in Thornton, we matched the DIA number with a low of 18 degrees coming at 3:19am.

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Thornton’s workweek starts with a warm up but with colder than normal temperatures

Monday, October 15th, 2018 4:58am MDT

Following on yesterday’s cold and snow and this morning’s record-setting cold, we dry up and clear out Monday. Temperatures will remain a good ways below normal bit it begins a warming trend and a calm, pleasant fall week.

Clear skies greet us to start the day and will continue throughout the day with no cloud cover expected. Conditions will be calm and dry.

Temperatures start out with a record low then will steadily warm toward a high in the low to mid-40s. That is well below the average high for the date of 66 degrees but a marked improvement over yesterday.

Tonight, skies remain clear with lows dipping to the mid to upper 20s.

For the rest of the week, we expect to see lots of sun, dry and calm conditions and warmer temperatures. Check out the extended forecast here.

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Winter travel safety – Ensure you and your vehicle are ready

Monday, October 15th, 2018 4:45am MDT
Are you and your vehicle ready for the winter weather ahead?

Are you and your vehicle ready for the winter weather ahead?

Before hitting the road, Coloradans need to ensure that they and their vehicles are prepared should inclement weather strike.

ThorntonWeather.com presents the first in a series from the National Weather Service (NWS) as part of Winter Weather Preparedness Week has declared by Colorado Governor John Hickenlooper.  Check back throughout the week for more winter preparedness stories.

Today’s message from the NWS highlights the importance of having a proper emergency kit in your vehicle and should the worst-case scenario occur where you get stuck, what you should do to survive.

601 AM MDT MON OCT 15 2018

Winter Travel Safety

Winter Weather Preparedness Week continues through Saturday.  Preparedness is a big part of this campaign. Before winter weather arrives in earnest, it is highly recommended that you prepare your car or truck for winter travel.

A well equipped vehicle has adequate tires, tire chains, tow rope, sand or cat litter for traction, shovel, tool kit, windshield scraper and brush, battery cables, first aid kit, flashlight, extra batteries, blankets and/or sleeping bags, extra clothing, candles, water-proof matches, high calorie packaged food for quick energy and an empty can to melt snow for drinking.

The best way to prevent treacherous winter travel is to avoid it. This can be done by staying informed about current weather and road conditions as well as the latest weather forecasts. Information on road conditions in Colorado is available on the web at www.cotrip.org or from the toll free number 1-877-315-7623. When calling from anywhere in Colorado, dialing 511 will also access the Colorado road reports. Additionally, a free smartphone application, CDOT Mobile, is available.

If you should become stranded during a winter storm, stay with your vehicle an d do not panic. If accompanied by others, take turns sleeping. Run the motor every hour for about ten minutes to maintain warmth, but keep windows open a little to prevent the buildup of carbon monoxide. Make sure the exhaust pipe is not blocked. Keep the car visible with brightly colored cloths tied to the side view mirrors, door handles, or external antenna. At night, turn on the dome light when running the engine. Exercise periodically by vigorously moving arms, legs, toes and fingers.

In the mountains, avalanches become a possibility in the winter, especially below steep slopes. Avalanches occasionally come down across roads, with little or no warning. However, avalanche control work is performed on many avalanche prone roads in Colorado, making the roads safer to travel. Caution is advised when traveling along avalanche prone roads, especially during and shortly after a heavy snowstorm or during periods of rapid snowmelt.

Very strong downslope winds occur at times mainly along the front range of Colorado. These Chinook and Bora winds can have gusts exceeding 100 mph. Persons traveling in light weight or high profile vehicles should avoid travel during these strong wind events especially on north-south oriented roads.

Roads which appear to be clear in the wintertime may actually be coated with a thin layer of ice, commonly known as black ice. This nearly invisible ice layer can cause you to rapidly lose control of your vehicle. Black ice is most common during the nighttime hours. If you detect black ice you should reduce your speed.

Please follow these winter travel safety recommendations which could save your life.

Winter Weather Awareness Week - Winter Travel Safety. (National Weather Service)

Winter Weather Awareness Week – Winter Travel Safety. (National Weather Service)


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Denver sets new record low maximum temperature for October 14

Monday, October 15th, 2018 12:01am MDT

Record Cold TemperaturesThe potent storm system that impacted us Saturday night through Sunday brought some snow but the most notable feature was the cold.  In fact, it was record setting.

The National Weather Service reports that the high temperature for Sunday, October 14 was only 27 degrees.  This absolutely destroys the old record low maximum for the date of 36 degrees set in 1969.

Here in Thornton, we saw our high reading just a touch warmer at 28 degrees.

Monday morning will see the temperature plunge and likely bring a record setting low as well.  After that, we do expect to see a gradual warming trend through the coming weekend.

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Colorado Winter Weather Preparedness Week introduction

Sunday, October 14th, 2018 5:30am MDT
Don't be caught off guard by winter weather! Remember the Christmas Eve Blizzard of 1982? Be prepared!

Don’t be caught off guard by winter weather! Remember the Christmas Eve Blizzard of 1982? Be prepared!

Winter weather in Colorado can be an inconvenience but more than that it can be deadly.  Emergency preparedness for major winter storms – as well as for other types of severe weather – is an important part of living in a state where conditions can change wildly from one moment to the next.

To help raise awareness of the need to be prepared for these occasions, the week of October 14th to October 20th has been proclaimed Winter Weather Preparedness Week in Colorado.

The National Weather Service will be issuing Public Information Statements each day this week to highlight the dangers of winter weather and how best to be prepared.  ThorntonWeather.com will be posting these important messages here to help you be prepared.  Please take the time to read and heed these messages – your life and the lives of your loved ones could depend on it.

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From the National Weather Service:

Public Information Statement
National Weather Service
Grand Junction CO

..Winter Weather Preparedness Week in Colorado…

Governor John Hickenlooper has proclaimed the week of October 18th through October 24th as Winter Weather Preparedness Week in Colorado. This is an excellent time for all individuals, families, businesses, schools, and media outlets to review their winter storm preparedness plans. It is especially important for all new arrivals to the state to become familiar with the National Weather Service watch and warning definitions, as well as winter safety procedures.

Snow in Colorado is important to the farmers, the ski areas, and for filling up reservoirs. However, winter storms often bring heavy snow, bitter cold air, high winds, low visibilities and slick roads. This can lead to dangerous travel conditions and other life threatening situations such as avalanches and very frigid wind chill temperatures.

To help you prepare for these hazards this coming winter…the National Weather Service will issue statements throughout the week to discuss:

Intro Winter Weather Preparedness Week
Part 1 Winter travel safety
Part 2 Watches…warnings…and advisories
Part 3 High winds
Part 4 Wind chill temperatures and hypothermia
Part 5 Avalanche safety
Review Winter Weather Preparedness Week review

Anyone who needs information on winter storms in Colorado should contact their nearest National Weather Service office.

Boulder office 303-494-3210
Grand Junction office 970-243-7007
Goodland Kansas office 785-899-7119
Pueblo office…
 – If you live near Pueblo 719-948-3371
 – If you live near Colorado Springs 719-573-6846
 – If you live near Alamosa 719-589-3232
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October 14 to October 20: This week in Denver weather history

Sunday, October 14th, 2018 5:28am MDT
This week in Denver weather history

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

The further we get in October the chances for snow increase and our look at this week in Denver weather history shows many significant snowstorms. Arguably the most notable was the infamous “Bronco Blizzard” of 1984 which dumped snow on the Mile High City while the Broncos faced off against the Green Bay Packers.

From the National Weather Service:


In 1969…record breaking extremely cold temperatures for so early in the season occurred. The high temperature of 26 degrees on the 13th was two degrees lower than the previous record minimum temperature of 28 degrees for the date set in 1885. The high temperature of 24 degrees on the 12th exceeded the record low temperature (22 degrees set in 1885) for the date by only 2 degrees. In addition… 3 new record low temperatures for the dates were set. The low temperature dipped to 10 degrees on the 12th breaking the old record (22 degrees in 1885) by 12 degrees. On the 13th the mercury plunged to a low of 3 degrees breaking the old record (28 degrees in 1885) by 25 degrees. On the 14th the temperature reached a minimum of 4 degrees breaking the old record (25 degrees in 1966) by 21 degrees.


In 1910…light smoke from nearby forest fires drifted over the city.

In 1966…the first measurable snow of the season caused widespread damage to trees and shrubs. The heavy wet snow totaled 6.9 inches at Stapleton International Airport where north-northwest winds sustained at 20 to 25 mph and gusting to 45 mph caused much blowing and drifting snow. South and east of Denver…up to a foot of snow fell. Heavy wet snow accumulations followed by freezing temperatures and strong winds resulted in extensive damage to trees…cars… And utility lines by falling limbs. A woman was killed by a falling snow laden tree limb in Denver. Several other people received minor injuries from falling tree limbs.

In 1987…rain drenched metro Denver. The South Platte canyon area southwest of Denver received the most with 1.11 inches at Kassler and 1.49 inches upstream at Strontia Springs. At Stapleton International Airport…0.62 inch of rain was measured…northwest winds gusted to 29 mph…and thunder was heard.

In 2007…a new 24-hour record of 2.65 inches of precipitation was set at Denver International Airport for the month of October; breaking the previous record of 2.58 inches set in 1892.


In 1873…smoke from several large forest fires in the mountains made the air very hazy in the city.


In 1952…the first measurable snowfall of the season left 1.2 inches of snow at Stapleton Airport. North winds gusted to 38 mph.

In 1974…rain changed to snow early in the day…but snowfall totaled only 1.0 inch at Stapleton International Airport where northeast winds gusted to 20 mph.


In 1871…a terrible wind occurred during a snow storm in the foothills above Boulder. Damage was minor.

In 1878…high winds reached sustained speeds of 60 mph at times.

In 1911…post-frontal northwest winds were sustained to 41 mph with gusts to 43 mph.

In 1948…strong winds struck the Boulder area. Winds averaged 50 mph at Valmont just east of Boulder. Wind gusts in excess of 60 mph were recorded at the Boulder airport. Wind gusts to 40 mph briefly reduced the visibility to 1 1/2 miles in blowing dust at Stapleton Airport.

In 1980…a rare October tornado touched down in Boulder… Damaging a vocational training building and throwing three nearby cars together damaging them extensively. A mile and half away several camper vehicles were thrown 200 feet. The storm also produced 1 inch diameter hail in the Boulder area.


In 1928…a thunderstorm produced hail shortly after midnight on the 15th. Rain changed to snow by evening. Through the afternoon of the 16th…the heavy snowfall totaled 7.3 inches in the city. North winds were sustained to 23 mph on the 15th.

In 1984…the heaviest October snowstorm in several years hit eastern Colorado with a vengeance. The storm was known as the “Bronco Blizzard” since it occurred during a nationally televised Monday Night Football game in Denver. One to two feet of snow fell near the foothills in west metro Denver with 2 to 3 feet in the foothills. Wind gusts up to 55 mph whipped the snow into drifts as high as 4 feet. The storm closed schools…roads…and airports. I-70 was closed both east and west of Denver. I-25 was closed south to Colorado Springs. Flights were delayed for several hours at Stapleton International Airport. Power outages were widespread. Snowfall totaled 9.2 inches at Stapleton International Airport where north winds gusting as high as 40 mph caused frequent surface visibilities of 1/4 to 1/2 mile in moderate to heavy snow and blowing snow overnight. The high temperature of only 35 degrees on the 15th was a record low maximum for the date.

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

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Thornton to enjoy a two-day warm up then turn much colder by end of the weekend

Friday, October 12th, 2018 5:39am MDT

A bit of a mixed bag of weather for us over the three day period. Friday and Saturday, while remaining cooler than normal, will be dry and see our warmest temps of recent days. Then, a significant system will move in bringing cold and snow Saturday night into Sunday.

We start things off on Friday with some clouds early then those will depart leading to sunny skies by mid-morning and lasting through the rest of the day. Temperatures will top out in the low 60s, still below normal but far warmer than recent days. Friday night skies will remain clear with lows in the mid-30s.

Saturday starts out sunny with a bit of an increase in cloud cover through the day as the next system gets closer. Highs will be near the 60 degree mark. Look for some breezy winds in the afternoon. By the evening, it will be mostly cloudy with the arrival of the cold front and storm system.

Some evening rain will be possible with a change over to snow after dark. Snow will continue overnight Saturday night into Sunday morning with low temps into the low 20s.

Sunday morning snow will ease with only a few flurries in the afternoon. We could see a few inches total accumulation from the event. Sunday temperatures will be quite chilly with highs only in the mid-20s. Overnight Sunday night into Monday morning, the mercury will drop to near 10 degrees.

Enjoy the initial warmth and be ready for the cold to come.

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Some warming, less precipitation for Thornton’s Thursday

Thursday, October 11th, 2018 5:04am MDT

After three days in a row with temperatures that failed to climb even above 40 degrees, we see some improvement in the mercury readings today. There will still however be a good bit of cloud cover and some chances for showers.

Cloudy skies start things off then to be followed by a bit of clearing later this morning. By this afternoon and particularly as we head toward evening we should see some sun peeking out.

Light showers will be possible from late morning through the evening with the best chances coming in the afternoon. Temperatures will warm to the mid-40s.

Tonight, any showers will come to an end before midnight with mostly cloudy skies above. Overnight lows will dip to the low to mid-30s.

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