Category Archives: Thornton Weather

Denver sets new record high minimum for November 12th

Denver broke the record high minimum temperature for the date yesterday.
Denver broke the record high minimum temperature for the date yesterday.

The Mile High City has enjoyed some great weather this past week and one weather record has officially been set. Just before midnight last night, the temperature at Denver International Airport dropped to 45 degrees. This sets a new record high minimum for November 12th, breaking the old record of 44 degrees set in 1894.  Thornton however wasn’t near as warm as we had a low temperature of 40.5 degrees.

The warm weather pattern though is set for a big change this weekend as you can see in our forecast. Two systems will begin to impact the area, the second of which arrives Saturday afternoon and could bring a good deal of snow to the area. Get the details on the Winter Storm Watch here.

It is important to remember though that the National Weather Service moved Denver’s official measurements to DIA 14 years ago from the former Stapleton site. This has caused a major change in Denver’s climate and weather records. Data shows that DIA runs hotter on the highs, colder on the colds and records less moisture than what stations closer to Denver do. This has resulted in Denver’s historical climate records being skewed.

Some say Denver’s climate records have forever been altered due to the station move and as such any weather record should have an asterisk attached to it. For more on the controversy, be sure to read our Examiner.com investigative series:

Examiner.com Investigates
Do Denver weather and climate records have an asterisk attached?

Part 1 – Overview and history.

Part 2 – Data analysis. Is there a problem?

Part 3 – Solutions, conclusions and why you should care.

Data analysis slideshow.

November 12, 2009 – Denver gets new National Weather Service monitoring station

Denver gets new National Weather Service weather station near downtown

Denver now as an official weather monitoring station closer to downtown but some say this doesnt solve the problem of the citys climate records being altered. (Examiner.com)
Denver now as an official weather monitoring station closer to downtown but some say this doesn't solve the problem of the city's climate records being altered. (Examiner.com)

It only took 14 years but Denver finally has an official monitoring station near downtown again. The new station amongst the greens of City Park Golf Course finally gives residents of Denver a place to see what the weather is doing closer to home.

With the opening of Denver International Airport in 1995, the National Weather Service moved its station to the new airport. That distance of 12 miles from the old Stapleton facility to DIA confounded citizens, television meteorologists and weather enthusiasts as they all noted that no one lives out at the airport and the conditions reported there do not reflect what is happening closer to town.

Recognizing the problem, a public-private partnership came together to do what they could to rectify the problem. The City and County of Denver, the Denver Museum of Nature and Science, the National Weather Service and NOAA, 7News Chief Meteorologist Mike Nelson and Colorado State Climatologist Nolan Doesken identified a site for the new station.

Eclar Fence and Mercury Electric donated the infrastructure for the new site. Weather equipment manufacturer Vaisala donated the weather monitoring hardware and services, estimated at up to $60,000.

Certainly there is little doubt the new station will provide area residents the ability to view conditions closer to where they actually live. The new station will not however address the very real problem of Denver’s climate records having been altered since the move to DIA. The National Weather Service has said the official records for Denver will still come out of DIA and as such many believe those records come with an asterisk.

There's more to this story on the Denver Weather Examiner's site!Why is there still a problem with Denver’s climate records?  What does the new station look like?  Check out the complete story including photos of the station, an interactive map and more on Examiner.com.

November 8 to November 14 – This week in Denver weather history

November 8 to November 14 - This week in Denver weather history
November 8 to November 14 - This week in Denver weather history

Wind is always a factor on the plains and the fall usually brings a great deal of it, especially in November.  Our look back at this week in Denver weather history shows that event and snow are quite common this time of year.

From the National Weather Service:

From the 7th to the 8th:

In 1969…wind gusts to 48 mph in downtown Boulder caused minor damage.

On the 8th:    

In 1896…southwest Chinook winds sustained to 42 mph with gusts as high as 46 mph warmed the temperature to a high of 53 degrees.
 
In 1977 near-blizzard conditions in blowing snow caused the closure of I-70 to the west of Denver in clear creek canyon and east of Denver to Limon.  Northeast wind gusts to 46 mph were recorded at Stapleton International Airport where snowfall totaled only 1.1 inches.
 
In 1984…a rare November thunderstorm produced west winds gusting to 31 mph…but only 0.04 inch of rain at Stapleton International Airport.
 
In 1996…high winds gusting from 80 to 100 mph were recorded at Wondervu in the foothills southwest of Boulder.  West northwest winds gusted to 32 mph at Denver International Airport.
 
In 2006…the temperature in Denver climbed to a high of 80 degrees.  This was the first time the temperature had ever exceeded the 70’s in November since records began in 1872. This new all-time record maximum temperature for the month of November was also a new daily record and the highest temperature ever recorded so late in the season.

Continue reading November 8 to November 14 – This week in Denver weather history

Denver sets new high temperature record for November 5th

Denver broke the record high temperature for the date today.
Denver broke the record high temperature for the date today.

Everyone in the Mile High City has been enjoying an extraordinarily beautiful November day today. As we mentioned in our morning forecast on Examiner.com, temperatures were expected to reach record-setting highs and that has been the case.

At 1:49pm the official temperature as taken at Denver International Airport reached 77 degrees. This broke the record high for the date last of 76 degrees set in 1945 and before that in 1916.

Here in Thornton we actually were a good bit warmer than the offical high.  ThorntonWeather.com reached a high of 79.9 degrees at 12:12pm.

As always, we have to ask the question: Is this really a record or not? Some say Denver’s climate records have forever been altered and as such any weather record should have an asterisk attached to it. Why? Get the details on that story here.

Thornton’s November weather preview – Our second snowiest month

November is Denvers second snowiest month.  What else can we expect?
November is Denver's second snowiest month. What else can we expect?

Typically November is a quiet weather month with plenty of nice, fall days but it can also turn wet with plenty of snow and moisture.  Just like Forest Gump’s proverbial box of chocolates, you never quite know what you are going to get.

Looking into the weather history books, we see that November is actually Denver’s second snowiest month, second only to March (April is third).  Historically we average 10.7 inches of snow during the month.

In 1994, November was the snowiest month of that year with 16.9 inches – over 12 inches of which fell within a 12 hour period on the 13th and 14th.  In 1991 we saw 29.6 inches of snow (the 2nd snowiest November) and the following year in 1992 we had 20.1 inches of snow (the 8th snowiest November).  Those examples though pale in comparison to the snowiest November on record which was in 1946 when a whopping 42.6 inches of snow fell! 

It isn’t always that snowy though. November 2002 was at the time the 16th month in a row with below normal precipitation and the calendar year of 2002 marked the driest in Denver weather history. This pattern of below normal precipitation continued for 19 months through February 2003. Since 1882, one year (1949) recorded no snow, six more recorded only a trace of snow and four had less than one inch of snow.

For the rest of the November weather preview including complete historical statistics, averages and much more, click here.

November 1 to November 7 – This week in Denver weather history

November 1 to November 7 - This week in Denver weather history
November 1 to November 7 - This week in Denver weather history

As we enter Denver’s second snowiest month, we of course see plenty of events involving that dominant weather condition.  Sadly we also see two occassions when the winter-like weather turned deadly.

From the 29th to the 1st:

In 1972…heavy snowfall totaled 15.5 inches at Stapleton International Airport.  However…the heaviest snow occurred on Halloween night when 7 inches fell on trick-or-treaters during a short 3-hour period.  I-25 was closed south of Denver.  North winds gusting to 29 mph caused some blowing snow on the 1st.  The snow started late on the 29th and ended during the mid afternoon on the 1st.  The greatest snow depth on the ground at Stapleton International Airport was 13 inches on the 1st.

From the 31st to the 1st:

In 1951…6.4 inches of snowfall were measured at Stapleton Airport.
 
In 1989…a Halloween storm dropped 3 to 6 inches of snow on metro Denver with the adjacent foothills receiving 5 to 10 inches.  Snowfall totaled 4.5 inches at Stapleton International Airport…where north winds gusted to 31 mph on the 31st.  Most of the snow fell on the evening of the 31st…but the storm left icy streets throughout metro Denver on the morning of the 1st…making it a “spooky” commute for many motorists.
 
In 2004…heavy snow fell in and near the foothills of Jefferson and Douglas counties.  Storm total snowfall included:  14.5 inches in Aspen Park…10 inches at Roxborough State Park and near Sedalia…8 inches near Bergen Park…and 7 inches in Highlands Ranch.  Snowfall totaled only 3.2 inches in the Denver Stapleton area.  Post-frontal northeast winds gusted to 41 mph at Denver International Airport.

On the 1st:

In 1896…northwest Chinook winds sustained to 40 mph with gusts to 46 mph warmed the temperature to a high of 60 degrees in the city.
 
In 1973…wind gusts to 92 mph were recorded in Boulder. West winds gusted to 41 mph at Stapleton International Airport where the Chinook winds warmed the temperature to a high of 70 degrees.
 
In 1989…a 39-year-old Lakewood man in a motorized wheelchair was found dead of exposure early in the morning after an overnight snowfall dumped 3 to 6 inches of snow across metro Denver.

From the 1st to the 2nd:

In 1892…snowfall totaled 5.0 inches in downtown Denver. This was the only snow of the month.
 
In 1956…heavy snowfall totaled 7.0 inches at Stapleton Airport.  The storm was accompanied by much blowing and drifting snow.  North winds gusted to 47 mph.
 
In 1991…the storm system which hit the Front Range at the end of October finished the job during the start of November.  Six inches of new snow were recorded at both Rollinsville and Morrison…while 2.9 inches of snow fell at Stapleton International Airport where northeast winds gusted to 17 mph.  The temperature climbed to a high of only 19 degrees on the 2nd…setting a record low maximum for the date.
 
In 1995…a winter storm dropped 5 to 8 inches of snow in the Front Range foothills.  The exception was at Golden gate canyon where a foot of new snow was measured.  Icy roads…fog…and blowing snow along I-70 in the foothills west of Denver caused dozens of accidents.  One man was killed when he lost control of his vehicle and was ejected when his truck hit a median and rolled over.  At least 20 other accidents involved minor injuries.  Only 1.0 inch of snow fell at the site of the former Stapleton International Airport where some freezing rain also fell.

Continue reading November 1 to November 7 – This week in Denver weather history

Thornton begins digging out from early winter storm

This image from the ThorntonWeather.com webcam was captured at the height of the storm.
This image from the ThorntonWeather.com webcam was captured at the height of the storm.

A two-day storm that saw areas around Denver measuring snow in terms of feet has moved out of the area and onto the plains. The lingering effects of the storm will be felt Friday in terms of slick roads in Denver and blizzard conditions to the east.

The early winter storm, while not entirely unusual, was the first major snow storm of the season and put Coloradoans to the test. Mercifully, the snow never fell at a particularly heavy rate and while it lingered for a long time, it allowed road crews and residents time to stay on top of the snowfall. Most schoolchildren were pleased to have received at least one snow day from the storm and many were the recipients of two unplanned days off.

At Denver International Airport, initial success at holding the storm’s effects at bay on Wednesday began to whither under the white onslaught on Thursday as winds picked up and the storm shifted east. Hundreds of flights were canceled from the airport’s major carriers including United Airlines, Frontier Airlines and Southwest Airlines.

At the height of the storm’s effects, the airport was reduced to two operating runways from the usual six and delays of up to four hours were occurring. All airlines anticipate being able to operate a normal flight schedule today.

How much snow did the Denver area receive? Here are some of the snowfall totals:

Aurora: 16 inches
Boulder: 18.8 inches
Broomfield: 20 inches
Centennial: 17 inches
Coal Creek Canyon: 46 inches
Denver International Airport: 12 inches (as of 6:00am Thursday)
Evergreen: 30 inches
Highlands Ranch: 24.5 inches
Littleton: 28.5 inches
Longmont: 12.4 inches
Parker: 14.5 inches
Thornton: 14.1 inches
Click here for a complete listing of storm reports.

The storm did push Denver into the record books and the ‘top 10 snowiest Octobers’ list. The National Weather Service will publish the official snow total from DIA for yesterday but even without the snow from yesterday, October 2009 makes the list. As of 6:00am on Thursday, DIA had recorded 14.5 inches for the month (12 inches from this storm). That makes it number 7 on the top 10 list for snowiest Octobers on record since 1882. Once today’s measurement is released, it is possible it will climb further.

There's more to this story on the Denver Weather Examiner's site!For the rest of the storm recap, the latest photos and much more, please visit the story on the Denver Weather Examiner.

Incredible time lapse video – Thornton’s October 2009 snowstorm

From the evening of October 27, 2009 through October 29, 2009, the Denver metro area was struck by a major, early winter snowstorm. The mountains and foothills to the immediate west of Denver were measuring the snowfall in feet while in the city more than a foot of snow fell in less than 72 hours.  Here in Thornton we recorded 14.1 inches of snow during the event.

This time lapse video below was captured by our east facing webcam. It begins early Tuesday morning (October 27th) and runs through midnight on Thursday, October 29th. As it starts, you can see the first day started out nice enough but by evening the wind was blowing and rain was falling. That soon changed to snow and the snowstorm was in full force for two days.

Early winter storm arrives in Colorado – Snow to continue

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. 

DENVER’S 10 SNOWIEST OCTOBERS
(1882-2008)

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
DENVER’S 10 COLDEST OCTOBERS
  (1873-2008)

 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.

Continue reading Early winter storm arrives in Colorado – Snow to continue

Major early winter storm heading for Thornton

Colorado is staged to be struck by a major early winter storm Wednesday and Thursday.
Colorado is staged to be struck by a major early winter storm Wednesday and Thursday.

Update: Tuesday, October 27th, 2009 5:15pm

A major early winter storm is on track to become the state’s first major snowstorm of the season. Areas in the mountains adjacent to the Denver Front Range may be measuring the snow in feet while parts of the Denver area could see up to a foot.

A cold front and trough dipping down from the north combined with a low pressure system moving over southern Colorado will combine creating a ‘perfect storm’ of sorts. Showers will begin spreading from the mountains this evening initially in the form of rain. As temperatures cool, that will change to snow, likely after midnight. Initially most of the precipitation will be west of I-25.

By Wednesday morning, up to 2 inches may have fallen in the Denver area and 3 – 4 inches in the foothills. As dawn breaks, conditions become ripe for a major storm as the upslope flow starts to kick in. The morning rush hour might be tolerable but by the time the afternoon arrives, things will be much different. At times during the day areas may see snowfall rates of 1 to 2 inches PER HOUR. Gusty winds will make for low visibility conditions and blowing and drifting snow.

Continue reading Major early winter storm heading for Thornton