Thornton, Colorado, USA
UpdatedMon, 08-Mar-2021 8:45am MST 


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Early winter storm arrives in Colorado – Snow to continue

Thursday, October 29th, 2009 6:08pm MST
Live CDOT webcam image from 120th & I-25 looking south.

Live CDOT webcam image from 120th & I-25 looking south.

Update, 6:10pm: As the storm starts to move to the east, blizzard conditions on the plains east of Denver are causing problems. I-70 remains closed from Airpark Road to Burlington and I-76 is closed from Lochbuie to Fort Morgan. Storm reports indicate blizzard conditions prevail with limited visibility and drifting snow. A Blizzard Warning is in effect for much of the northeastern Colorado plains and will remain so until 6:00am Friday.

Closer to town, things are finally starting to ease up along the Front Range and in the metro area. Gusty winds and cold temperatures will keep wind chills down into the teens and make it uncomfortable to be outside. Drifting snow on roadways is possible thanks to those gusty winds from the north. Additional light snow can be expected, mainly in areas to the west and south.

The Winter Storm Warning for the metro area was allowed to expire at 6:00pm as planned. However, roads are likely to get slick as temperatures drop overnight so please use caution.

Update, 12:38pm:  October 2009 enters the record books as the 7th snowiest October on record in Denver. The National Weather Service reported that as of 6:00am today, the official station at Denver International Airport had recorded 14.5 inches of snow fall for this month. 10.6 inches of that had fallen in the previous 24 hours. With the early measurement and the fact the snow is expected to continue throughout the day, it is possible the month will climb further up the charts (see below).

It is also notable that Denver will likely finish the month as one of the coldest Octobers on record. Thus far the average temperature for October 2009 has been 43.9 degrees. Were the month to end today, that would place it in a tie for the third coldest October on record. 


31.2   1969
22.7   1906
22.1   1997
17.8   1923
16.4   1897
16.2   1929
14.5   2009
14.0   1889
13.8   1905
13.6   1908
13.1   1984

 39.0   1969
 43.3   1925
 43.9   2002, 2009 *
 44.3   1923
 44.8   1984
 45.9   1970
 46.3   1877
 46.4   1913, 1919
 46.6   1905
 46.7   1873

* As of October 28, 2009

Update, 10:35am: The snow keeps falling! Light snow will continue across the urban corridor for the rest of the morning with 1 to 4 inches additional accumulation possible. Some areas south may see heavier snow rates, particularly to the south and east.

Blizzard-like conditions are possible in open areas where there is a good bit of wind blowing. Travel to the east is best avoided at this time due to low visibility and icy conditions. Chain laws are actually in effect on I-76 at Wiggins due to hazardous conditions. I-25 remains closed from Wellington to the Wyoming border.

At Denver International Airport, flight delays continue to mount. Delays of 3 to 4 hours are being experienced for arrivals and departures as DIA ground crews struggle to keep up with the falling snow. Frontier Airlines reports that additional cancelations are possible.

Storm spotters have reported amounts as high as 44 inches in Coal Creek Canyon and snowfall reaching near 3 feet is being seen in many places in the foothills. Closer to town, west and south are reporting up to 18 inches while central Denver is reporting close to one foot.  ThorntonWeather.com has recorded 14.1″ so far! Click here for the latest storm reports from across the area.

ThorntonWeather.com is of course your source for local information on the storm as it develops.  We will also be updating the Denver Weather Examiner site as things develop.  Here are some quick links to pages you may find handy:

Why do we link to Examiner.com?  Click here to find out.

Update, 6:35am, Thursday, October 29, 2009: Thornton and a large portion of Colorado continue to be hammered by a two-day long storm that has dumped more than two feet of snow in the adjacent foothills and a foot across much of the metro area. At ThorntonWeather.com we have recorded 13.2 inches of snow thus far for the event.  While the early winter storm has created its share of problems, the relatively slow snowfall rate has allowed it to be manageable by most standards.

A Winter Storm Warning remains in effect for the Front Range through 6:00pm tonight. The low pressure system that is moving through is taking its time and it will continue to generate periods of moderate to heavy snowfall throughout the morning and early afternoon. How much snow has fallen?  See the latest storm reports below. 

Additional snow accumulations of 3 to 7 inches are possible for Denver. The foothills and Palmer Divide area could see up to 12 inches. Gusty winds will continue to create blowing snow, especially on the plains, and power outages and broken trees are possible under the weight of the snow. Temperatures will struggle to reach the freezing mark today with wind chill temperatures into the teens.

The snowstorm which started Tuesday evening by initially delivering rain which changed to snow overnight and into Wednesday has created its share of headaches. Many Denver area schools were closed on Wednesday and virtually all are today. Government facilities and many businesses closed early on Wednesday to allow employees extra time to get home.

Various portions of the interstate highway system in Colorado and Wyoming were shut down and some remain closed at this time. In Colorado, I-25 is closed north of Wellington to the Wyoming border. Chain laws are in effect for most mountain passes including Raton, Mt. Vernon Canyon, Monarch, La Veta, and Wolf Creek. Independence Pass and Loveland Pass are closed due to winter conditions. I-80 in Wyoming from Laramie to Cheyenne is closed as is most of I-25 from Cheyenne to Chugwater.

Denver International Airport remains open in the face of the storm although airlines did cancel flights and some lengthy flight delays were being experienced. The airport says it expects cancelations to continue today.

Frontier Airlines said Thursday morning it didn’t expect additional cancelations beyond those that were already announced. United Airlines and Southwest Airlines were offering travel waivers through today allowing passengers to change their flights if they desired. Travelers should check with their airline before heading to the airport.

Update 8:20pm:  Colorado weather has its extremes and this storm certainly is shaping up to fit that bill.  Snow totals are mounting with areas to the west and south receiving the most.  In the Denver metro area, most areas have received at least six inches with most recording more and additional accumulations are expected overnight.

As the temperature has started to drop and traffic on the roads has decreased, snow is slowly starting to accumulate on roadways.  Bridges and ramps are getting very slick and soon the rest of the road system will follow suit. 

At Denver International Airport, most airlines have reported some cancelations and many arrivals and departures as delayed.  Deicing operations are in effect so those flights that are getting out are slow in doing so. 

Numerous school districts have already announced they will be closed on Thursday.  Among them are St. Vrain Valley Schools, Adams District 12, Adams District 50, Brighton School District 27J, Jeffco Public Schools and Aurora Public Schools.  Click here for a complete listing.

A Winter Storm Warning remains in effect for much of the state including the Denver area until 6:00pm Thursday.  The storm system that is causing widespread problems is moving a bit slower than originally forecast and that will delay the end of the snow.  An additional 4 to 8 inches of snow can be expected overnight followed by 3 to 7 inches more during the day on Thursday. 

Total snow accumulations for the storm event will range from 14 to 28 inches are possible with up to 36 inches in the foothills west of Denver.  On the plains accumulations will range from 6 to 12 inches and blizzard conditions are possible.

Chain laws are in effect for most Colorado mountain passes including at the Eisenhower Tunnel, Vail Pass, Berthoud Pass, Monarch Pass and La Veta Pass.  US 287 is closed from Ted’s Place to the Wyoming border.  In Wyoming, I-80 between Laramie and Cheyenne is closed as is I-25 from Cheyenne to Wheatland.

The best advice at this time is to stay home and avoid travel if at all possible.  Needless to say, tomorrow morning’s commute will be a rough one for those heading to work.  Please allow plenty of extra time and take it slow.

Update 7:15pm: Adams 12 and Adams 50 will be CLOSED tomorrow.  No word yet on Brighton 27-J.

Update 4:30pm:  The snow keeps falling and the end is a ways away yet. Roads have been wet and slushy to this point however as the sun goes down and temperatures drop we will see more accumulation and icing of the roadways.  That, coupled with winds blowing at up to 25mph will create hazardous driving conditons across the Front Range. 

In the high country, US 287 from Ted’s Place to the Wyoming border is closed due to adverse weather condtions.  Chain laws are in effect for most major passes including at the Eisenhower Tunnel, Vail Pass, Berthoud Pass, Monarch Pass and La Veta Pass.  In Wyoming, I-80 between Laramie and Cheyenne is closed entirely. 

Total snowfall accumulations are still forecast to be in the 10 to 18 inch range in the metro area and up to 24 inches in the foothills. Locally higher amounts may be seen in some areas.  Thus far ThorntonWeather.com has recorded 7.8 inches so we are getting close to that range!

Update, 12:40pm : Denver’s October 2009 snowstorm continues in full force. Heavy snow has been and is currently being experienced across much of the Front Range. Storm reports from spotters are showing totals from 15 to 20 inches in the foothills and 5 to 8 inches across many parts of the metro area.

Winds will be increasing as the day progresses making what are already tough driving conditions worse. Needless to say afternoon rush hour is likely to be a big mess as moderate to heavy snow will continue to fall.

Total snowfall accumulations are still forecast to be in the 10 to 18 inch range in the metro area and up to 24 inches in the foothills. Locally higher amounts may be seen in some areas.  See below for a snowfall forecast map.

There are reports of tree branches breaking on trees that still have leaves and this will continue to be a problem. Power outages are also a possibility as the snow sticks to and weighs down power lines.

At Denver International Airport, some airlines have canceled flights including United, Frontier and Southwest. If you are flying out today or tomorrow or are expecting someone to arrive, check with your airline before going to the airport.

A Winter Storm Warning is in effect today lasting through 6:00pm Thursday. The warning area includes not only Denver but much of northeastern Colorado, the mountains and the Western Slope. Winter storm conditions will prevail throughout today and most of Thursday so things are only going to get worse from here on out. Please be careful! Travelers should check the Colorado Department of Transportation site for the latest road conditions and closures.

Update, 10:15am: The snow continues to pile up. Light to moderate snow will continue across the Denver area. With the additional snowfall many streets and highways are starting to see accumulation and traveling is quickly becoming hazardous. Area residents need to be aware of the deteriorating conditions and exercise caution.

These are some of the latest updates from across the area:

  • Many metro are cities are on accident alert including Thornton. If you are in an accident and no one is injured, exchange information with the other driver and contact the police afterwards.
  • I-25 northbound at Highway 7 is current closed due to an accident and winter conditions. Traffic is exiting at Highway 7 and getting back at the on-ramp. Expect long delays.
  • I-80 in Wyoming is closed from Cheyenne to Laramie.
  • Denver International Airport reports that several airlines have canceled flights including United and Frontier. Check with your airline before going to the airport. Winter driving conditions can be expected on Pena Boulevard.
  • Loveland Pass / US-6 has re-opened over chain laws are in effect.
  • ThorntonWeather.com is wondering about Adams 12’s decision to be open today! 
  • The wet weather coupled with sub-freezing temperatures has frozen our anenometer (wind sensor).  So much for measuring wind chill!

Original post, 10/28/09, 6:21am: A major early winter storm has arrived in Colorado and while snow accumulations thus far have been relatively minor, much more is to come. As expected the initial stages of the storm brought rain Tuesday evening which changed to snow overnight as the temperature dropped. Thus far anywhere from 1 to 3 inches of wet, slushy snow have fallen in the Denver metro area with more in the forecast.

  • School closure update:  It appears Adams County Five Star School District 12 will be OPEN today.  Adams County District 50, Brighton 27-J, Jefferson County Public Schools and others are closed.  See the latest list on 9News’ website.

The morning commute today is sure to be a slow, wet one. While most streets in the central part of Denver are currently clear from snow, they are extremely wet and areas to the west are now beginning to see accumulation on the highways. Bridges and overpasses are becoming slick and will present challenges for drivers today.

In the high country, chain laws are in effect on I-70 westbound to the Eisenhower Tunnel and eastbound at Mt. Vernon Canyon. Loveland Pass / US-6 has been closed due to adverse conditions. Chain laws are also in effect for the Berthoud, Red Mountain, Monarch and Wolf Creek passes.

Snowfall amounts of 4 to 8 inches can be expected between Wednesday morning and Wednesday evening in the Denver area. Areas along the foothills and the Palmer Divide can look forward to 6 to 12 inches.

This storm however is a multi-day event and the snow if forecast to continue into Wednesday night and mid-afternoon Thursday. Total accumulations for the event will range from 8 to 14 inches in the Denver area and 10 to 18 inches in the foothills. Some areas where upslope conditions are ripe may experience higher accumulations.

As is oftentimes the case with storms like this, wind will be a factor as well. Blowing snow will make for drifting snow and decreased visibility. This will certainly impact driving conditions and has already begun to take its toll on flights into and out of Denver International Airport. Frontier Airlines has announced it is proactiviely canceling some flights (details here).  Numerous school in the metro area and the foothills are reporting that they will be closed for the day Wednesday.

With as wet as the snow is, the weight of the snow may become a problem for power lines and trees. Not all trees have lost their leaves yet and those that have them will quickly become weighted down with the heavy, wet snow. Similarly, as the snow sticks to power lines we may start to see power outages in some areas.

A Winter Storm Warning is in effect today lasting through 6:00pm Thursday. The warning area includes not only Denver but much of northeastern Colorado, the mountains and the Western Slope. Winter storm conditions will prevail throughout today and most of Thursday. Residents should take their time if they must travel and be prepared.

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