Tag Archives: December Weather

December 2 to December 8: This Week in Denver Weather History

This Week In Denver Weather History
December 2 to December 8: This Week in Denver Weather History

This week has historically been an extremely eventful one in Denver with many notable weather events, most of which are snow or wind related.  The most significant event occurred 99 years ago when the city received its biggest snowstorm on record – an astonishing 45.7 inches.  Details on that event and many others are below.

From the National Weather Service:

30-2

In 1975…very strong Chinook winds up to 100 mph caused damage to homes…aircraft…aircraft hangars…mobile homes… Cars…and power lines along the eastern foothills. Strong northwest winds gusted to 39 mph at Stapleton International Airport on both the 30th and the 1st.

1-2

In 1933…apparent post-frontal heavy snowfall totaled 8.0 inches across downtown Denver. North winds were sustained to 17 mph with an extreme velocity to 18 mph on the 1st.

In 1981 strong winds gusted to over 70 mph along the foothills. A peak gust to 100 mph was recorded at Wondervu. A gust to 94 mph was recorded just west of Boulder. Roofs on houses were damaged in the Evergreen area…and some mobile homes also were damaged. At Stapleton International Airport…northwest winds gusted 44 mph on the 1st and 37 mph on the 2nd.

1-5

In 1913…the 1st marked the start of the heaviest 5-day total snowfall in the city’s history. During this period snowfall totaled 45.7 inches. Starting on the 1st…snow fell intermittently for 3 days and accumulated a little over 8 inches. On the 4th and 5th…an additional 37.4 inches of snow fell. At Georgetown in the foothills west of Denver even more snow fell…86 inches over the 5 days with the most…63 inches…on the 4th.  In Colorado…snowfall was heavy along the eastern slopes of the mountains from the palmer divide north. High winds during the storm caused heavy drifting…which blocked all transportation. Snow cover of an inch or more from the storm persisted for 60 consecutive days from the 1st through January 29…1914. Additional snowfall in December and January prolonged the number of days. This is the third longest period of snow cover on record in the city.

2

In 1893…northwest winds were sustained to 42 mph with gusts to 46 mph. Snowfall was only 1.4 inches in the city.

In 1895…0.01 inch of melted snow from 0.7 inch of snowfall was the only measurable precipitation of the month in downtown Denver…ranking the month the 3rd driest December on record.

In 1899…post-frontal northeast winds sustained to 44 mph with gusts to 59 mph caused the temperature to plunge from a high of 55 degrees to a low of 15 degrees. Snowfall was only 1.0 inch.

In 1902…apparent post-frontal northwest winds were sustained to 45 mph with gusts to 53 mph. A trace of snow fell.

In 1905…only a trace of snow fell in downtown Denver. This was the only snow and precipitation for the month… Ranking the month the second driest and the second least snowiest December on record.

In 1921…snowfall was 5.5 inches in downtown Denver. Northwest winds were sustained to 24 mph with an extreme velocity of 25 mph.

In 1951…a vigorous pacific cold front produced a northwest wind gust to 51 mph at Stapleton Airport where brief blowing dust was observed.

In 1957…a strong pacific cold front produced northwest wind gusts to 54 mph at Stapleton Airport where the surface visibility was briefly reduced to 1 1/2 miles in blowing dust.

In 1977…high winds in Boulder lifted a warehouse from its foundation and ripped it apart. Wind gusts from 60 to 103 mph toppled and injured a man while walking. Winds were clocked to 104 mph at Nederland…100 mph at Morrison…and 62 mph at Rocky Flats. Northwest winds gusted to 41 mph at Stapleton International Airport.

In 1996…for the second day in a row high winds ripped the Front Range foothills. Winds gusted to 81 mph in Golden Gate Canyon. West-northwest winds gusted to 37 mph at Denver International Airport.

Continue reading December 2 to December 8: This Week in Denver Weather History

Thornton’s December preview: Hoping for snow

Thus far the snow season has been far less than kind to Colorado.  Snow totals are running well below normal from the plains to the Rockies.

December may bring some hope as the month is our third snowiest. The month brings with it the official start to winter and the month usually brings with it our first real taste of Arctic temperatures.

Precipitation can be hit or miss with monster snowstorms possible but we have also seen starkly dry years.

Current long range forecasts indicate we may very well see continued dry and warm weather.

Get all the details on Thornton’s December weather including a look back at historical events and a look at the long range forecast in our December weather preview here.

December 2011 Thornton weather recap: A cold and snowy close to the year

December 2011 will go into the books as a cold and snowy month. (ThorntonWeather.com)
December 2011 will go into the books as a cold and snowy month. (ThorntonWeather.com)

Thornton closed out 2011 with a month that while not necessarily historical, brought significant weather to the area.  Snow was one of the bigger stories as we piled up a good bit of the white stuff and temperatures were below normal for the month.

December 2011 came in like a lion as a cold front and associated upper level storm arrived during the first week of the month.  Denver International Airport recorded 9.2 inches of snow during the period while here in Thornton we saw 10.7 inches.  Temperatures were a bone chilling 17.2 degrees below normal during that time.

The middle of the month saw the weather moderate and return to more seasonal conditions.  Temperatures overall however remained slightly below average.

With the third week of the month we saw another snowstorm arrive on the 21st and 22nd.  Denver recorded 7.3 inches of snow.  Thornton once again saw higher totals as we measured 9.1 inches.

The constant snow cover kept temperatures down through the first few weeks of the month and for a time it looked like the month could make it into the books as one of the coldest on record.  A late month warming trend however changed that situation.

In the end, December 2011’s average temperature was 26.6 degrees.  While this was 3.4 degrees below normal, it pushed the month out of ‘top 10 coldest’ contention.

The snow during the month, while also not record setting, was significant.  Denver wrapped up December with 16.5 inches – nearly double the 8.5 inch December average.  For the season to date we stood at 29.5 inches giving us a good start toward the 53.5 inch seasonal average.

In terms of precipitation, 0.78 inches was recorded in Denver which was 0.47 inch above normal.

At DIA, temperatures ranged from a high of 58 degrees on the 18th down to a low of -5 degrees on the 6th.  Thornton saw similar marks with a high of 59.7 degrees, also on the 18th, and a low of -6.5 degrees on the 6th.

Mother Nature did close out the month and 2011 with a significant windstorm across northeastern Colorado.  The New Year’s Eve event saw DIA record a 59mph wind gust and Thornton saw 45mph.  Many other areas saw much higher speeds – click here for a summary of the event.

Click here to view the Thornton climatological summary for December 2011.  Below is the official Denver summary from the National Weather Service.

CLIMATE REPORT
NATIONAL WEATHER SERVICE BOULDER, CO
335 PM MST TUE JAN 3 2012

...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF DECEMBER 2011... 

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2012

WEATHER         OBSERVED          NORMAL  DEPART  LAST YEAR`S
                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
                                          NORMAL
................................................................ 
TEMPERATURE (F)
RECORD
 HIGH              79   12/05/1939
 LOW              -25   12/22/1990
                        12/24/1876
HIGHEST            58   12/18        79     -21       70  12/14
LOWEST             -5   12/06       -25      20        0  12/31
AVG. MAXIMUM     38.5              42.8    -4.3     48.9
AVG. MINIMUM     14.8              17.1    -2.3     19.6
MEAN             26.6              30.0    -3.4     34.3
DAYS MAX >= 90      0               0.0     0.0        0
DAYS MAX <= 32      7               5.8     1.2        2
DAYS MIN <= 32     30              29.4     0.6       28
DAYS MIN <= 0       2               2.0     0.0        1

PRECIPITATION (INCHES)
RECORD
 MAXIMUM         5.21   1913
 MINIMUM         0.00   1881
TOTALS           0.78              0.31    0.47     0.22
DAILY AVG.       0.03              0.01    0.02     0.01
DAYS >= .01         6               4.1     1.9        2
DAYS >= .10         3               1.1     1.9        2
DAYS >= .50         0               0.1    -0.1        0
DAYS >= 1.00        0               0.0     0.0        0
GREATEST
 24 HR. TOTAL    0.48   12/21 TO 12/22           12/30 TO 12/31

SNOWFALL (INCHES)
RECORDS
 TOTAL           57.4   1913
TOTALS           16.5               8.5

DEGREE_DAYS
HEATING TOTAL    1182              1086      96      944
 SINCE 7/1       2434              2463     -29     2072
COOLING TOTAL       0                 0       0        0
 SINCE 1/1        964               769     195      870

FREEZE DATES
RECORD
 EARLIEST     09/08/1962
 LATEST       06/08/2007
EARLIEST                        10/07
LATEST                          05/05
.................................................. 

WIND (MPH)
AVERAGE WIND SPEED              9.4
RESULTANT WIND SPEED/DIRECTION   4/224
HIGHEST WIND SPEED/DIRECTION    45/270    DATE  12/31
HIGHEST GUST SPEED/DIRECTION    59/270    DATE  12/31

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.40
NUMBER OF DAYS FAIR           15
NUMBER OF DAYS PC             12
NUMBER OF DAYS CLOUDY          4

AVERAGE RH (PERCENT)     62

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              0     MIXED PRECIP               0
HEAVY RAIN                0     RAIN                       0
LIGHT RAIN                0     FREEZING RAIN              1
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                1     SNOW                       5
LIGHT SNOW                6     SLEET                      0
FOG                      11     FOG W/VIS <= 1/4 MILE      3
HAZE                      4

-  INDICATES NEGATIVE NUMBERS.
R  INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T  INDICATES TRACE AMOUNT.

National Weather Service releases summary of New Year’s Eve windstorm

A windstorm pummeled northeastern Colorado on New Year's Eve 2011.
A windstorm pummeled northeastern Colorado on New Year's Eve 2011.

Northeastern Colorado closed out 2011 with pummeling high winds on New Year’s Eve.  Wind gusts of tropical and hurricane storm strength slammed into the region causing damage and claiming one life.

In the Denver metro area gusts approaching 50mph were common while areas in the foothills and mountains to the west and on the plains to the northeast saw much higher speeds.  Here in Thornton we recorded a maximum gust of 44.9mph in the predawn hours.

Following is a summary of the event from the National Weather Service:

Post-Storm Summary of the New Year’s Eve Windstorm

A fast moving upper level storm system, along with a deep low pressure system over Nebraska and high pressure building over Utah, combined to create a powerful windstorm across Northeast and North Central Colorado on December 31st. The high wind event began in the mountains after midnight Friday night, and then spread across the plains early Saturday morning. The height of the windstorm on the plains occurred around mid day when numerous gusts between 60 and 80 mph were reported.

The strong winds produced damage to fences and some roofs, and also knocked down trees resulting in power outages to approximately 19,000 residents. Some trucks were also blown off the road, and 1 fatality occurred due to a flying tree limb on U.S. Highway 36 north of Boulder.

Visibilities over the northeast corner of the state were also reduced significantly by a combination of blowing dust and blowing snow.

The following is a list by county of maximum wind gusts associated with this powerful windstorm…

Location Maximum Wind Gust

Adams…
Bennett 60 MPH
Front Range Airport 60 MPH

Arapahoe…
Deer Trail 59 MPH
Centennial 55 MPH

Boulder…
1 W Lyons 101 MPH
4 NW Boulder 84 MPH
Boulder 81 MPH
NCAR Mesa Lab 79 MPH
North Longmont 75 MPH
Boulder Municipal Airport 59 MPH
2 NNW Louisville 58 MPH

Broomfield…
Rocky Mountain Regional Airport 58 MPH

Clear Creek…
Berthoud Pass 94 MPH

Denver…
Buckley AFB 64 MPH
Denver International Airport 59 MPH

Douglas…
Centennial Airport 55 MPH
10 SSE Castle Rock 52 MPH
Highlands Ranch 50 MPH

Elbert…
10 E Parker 67 MPH
Elizabeth 55 MPH

Grand…
Berthoud Pass 94 MPH
11 N Kremmling 80 MPH
9 S Fraser 80 MPH

Jefferson…
3 SSE Pinecliffe 111 MPH
3 S Golden 86 MPH
Highway 72 and 93 Junction 79 MPH
National Wind Technology Center 77 MPH
3 NNW Morrison 76 MPH
4 S Rocky Flats 73 MPH
2 E Golden 67 MPH
2 E Northeast Lakewood 64 MPH
2 ENE Lakewood 64 MPH
3 W Conifer 62 MPH
Wheat Ridge 55 MPH

Larimer…
4 E Loveland 73 MPH
Natural Fort Rest Area 71 MPH
5 NW Fort Collins 67 MPH
3 NE Loveland 67 MPH
Wellington 63 MPH
4 E Fort Collins 63 MPH
Virginia Dale 62 MPH
Fort Collins 57 MPH

Lincoln…
3 W Cedar Point 80 MPH
Limon Airport 74 MPH

Logan…
Sterling Airport 73 MPH
Sterling 70 MPH
Crook 65 MPH

Morgan…
Wiggins 61 MPH

Park…
Kenosha Pass 79 MPH
Fairplay 77 MPH
Wilkerson Pass 58 MPH

Phillips…
4 E Haxtun 70 MPH
Holyoke 63 MPH
8 S Holyoke 62 MPH

Summit…
7 S Frisco 126 MPH
9 E Dillon 90 MPH
7 SSW Frisco 86 MPH

Washington…
Akron 75 MPH
Woodrow 73 MPH
5 NW Woodlin School 67 MPH

Weld…
4 ENE Eaton 80 MPH
3 NNW Cornish 79 MPH
2 NNW New Raymer 77 MPH
10 NE Pawnee Buttes 74 MPH
Briggsdale 72 MPH
9 NNE Briggsdale 72 MPH
7 N Rockport 70 MPH
Greeley Airport 67 MPH
4 ENE Severance 63 MPH
Eaton 63 MPH
1 N Greeley 62 MPH
6 E Berthoud 62 MPH
2 W Keenesburg 58 MPH
Milliken 56 MPH

12/31/11 - Here is surface pressure analysis (light blue lines) and infrared satellite image at 12 PM MST near the height of the windstorm.  Note the large difference in pressure between the surface low pressure over southeast Nebraska and high pressure centered over southern Idaho, and the resulting tight gradient across Colorado.  This is a key feature in windstorms across the Front Range and High Plains. (NWS)
12/31/11 - Here is surface pressure analysis (light blue lines) and infrared satellite image at 12 PM MST near the height of the windstorm. Note the large difference in pressure between the surface low pressure over southeast Nebraska and high pressure centered over southern Idaho, and the resulting tight gradient across Colorado. This is a key feature in windstorms across the Front Range and High Plains. (NWS)
12/31/11 - A 6 hour model forecast of 700 mb winds (approximately 10,000 ft MSL) and surface pressure.  700 mb wind strength is noted by flags (50kts) plus barbs (10kts for full & 5kts for half).  Stronger downslope flow and large scale subsidence which occurred in this storm can bring these stronger winds aloft down to the surface. (NWS)
12/31/11 - A 6 hour model forecast of 700 mb winds (approximately 10,000 ft MSL) and surface pressure. 700 mb wind strength is noted by flags (50kts) plus barbs (10kts for full & 5kts for half). Stronger downslope flow and large scale subsidence which occurred in this storm can bring these stronger winds aloft down to the surface. (NWS)
12/31/11 - A surface plot of weather stations across the region during the windstorm.  This image was taken at 1 PM MST, when the maximum winds were spreading across the northeast plains of Colorado.  At this time, the strongest corridor of winds stretched from Sterling (gusting to 59 kts or 68 mph), to Akron (gusting to 63 kts or 72 mph) to Burlington (gusting to 66 kts or 76 mph). (NWS)
12/31/11 - A surface plot of weather stations across the region during the windstorm. This image was taken at 1 PM MST, when the maximum winds were spreading across the northeast plains of Colorado. At this time, the strongest corridor of winds stretched from Sterling (gusting to 59 kts or 68 mph), to Akron (gusting to 63 kts or 72 mph) to Burlington (gusting to 66 kts or 76 mph). (NWS)

Recent snows put Denver snowfall far ahead of last year and above average

ThorntonWeather.com Snow Report
Recent snows have put Denver ahead of the game on snow totals while the mountains remain drier than normal.

While none of the snowstorms seen so far this year in Denver have been major ones, they have delivered the much needed snow that was missed last year.  December’s snowfall totals will finish well above average and have helped put the city’s seasonal snowfall totals above normal to date .

December’s snowfall total for the month stands at 16.5 inches (20.1 inches in Thornton).  This is nearly double the 1981 – 2010 historical average for the month of 8.5 inches.

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Leading up to Christmas, one storm slammed southeastern Colorado with blizzard conditions.  A second storm took a more northern track delivering a shot of snow to northern Colorado (see image below).  The snow cover ensured a white Christmas and NASA satellite imagery showed the Centennial State blanketed in white for the holiday.

For the season to date, the Mile High City has recorded 29.5 inches of snow (versus 34.6 inches in Thornton).  This puts us ahead of the pace of the average of 22.5 inches that we normally see through the end of December.

This stands in stark contrast to last season when Denver saw a paltry 22.8 inches of snow over the entire season and Thornton recorded 21.3 inches.  For comparison, in an average season we see 53.8 inches.

Not all is well in Colorado however with the snow.  While the plains are seeing above normal totals, the mountains are lagging.

Some ski areas like Cooper Mountain near Leadville have yet to even open for the season.  Others have had enough snow to allow skiers on their slopes but have runs that they have not yet been able to open due to the lack of snow. Get the latest ski area snow reports here.

Snowpack across the state is below average in seven of the eight major basins with only the Upper Rio Grande reporting above normal (101%).  The South Platte basin which includes the Colorado Front Range mountains stands at only 85% of normal and Western Slope basins are seeing as little as 65% of normal.

Snowfall totals from Denver's December 21 - 22, 2011 snowstorm.
Snowfall totals from Denver's December 21 - 22, 2011 snowstorm.

City of Thornton’s WinterFest to enjoy great weather for the festivities

One of many ice sculptures on display at WinterFest.  View more images from the first night of the festival below. (ThorntonWeather.com)
One of many ice sculptures on display at WinterFest. View more images from the first night of the festival below. (ThorntonWeather.com)

The City of Thornton’s annual winter festival is in full swing and after a chilly start Friday, the weather for the rest of the events looks to be much milder.

Santa Claus arrives safely last night and as always, the city has a full slate of events surrounding WinterFest at the Multipurpose Fields at 108th Ave and Colorado Blvd.  Residents can ice skate all day long and into the night, the ice carving demonstration is underway and of course Santa’s Village is open.

Tonight the Thornton Community Band will take to the stage at 7:00pm showcasing our community’s musical talent.  After the concert, Thornton will put on a fireworks show at 8:30pm, one of the few in Colorado during the winter and always the best.

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Sunday features the wide variety of fun in Santa’s Village. Tomorrow night the Thornton Community Chorus will raise their voices in celebration of the season.

For the weather, today we’re heading for a high of 45 degrees with just a light wind.  It will dip to right around the freezing mark by 7:00pm when the band concert takes place and then down to 28 degrees for the fireworks at 8:30pm.

Tomorrow will be even warmer with plenty of sun above as we head for a high of 48 degrees with light winds.  When the chorus takes to the stage at 6:30 it will be around 32 degrees.

Check out some of the photos we took of WinterFest last night below – then head on down and join the fun!

Second snowstorm in three days hits Thornton, third round on the way

A view of the Flatirons near Boulder on December 3, 2011 following the second snowstorm in three days. (National Weather Service)
A view of the Flatirons near Boulder on December 3, 2011 following the second snowstorm in three days. (National Weather Service)

The meteorological winter starts on December 1 and Old Man Winter is making sure we know he is around.  Two snowstorms have hit Thornton in a three day span and more snow is on the way.

On Thursday the first storm brought 5.1 inches to Thornton.  Denver officially recorded 5.7 inches at Denver International Airport (DIA).

Shortly before midnight last night, the snow began falling again and continued through noon.  Here in Thornton we recorded 4.9 inches with the latest system.

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It is interesting to note that this brings our seasonal snowfall total to 24.5 inches.  For comparison, we recorded a dismal 21.2 inches during all of the last season!  In an average season, December received 61.7 inches.

Yet another storm system is on its way and is expected to arrive tomorrow evening.  Right now it isn’t look near as impressive as the last two but Thornton may see another inch or two out of it.

Over the longer term, colder than normal temperatures are expected to last through this week.  The first half should be dry but Thursday night into Friday we may see snow again.  Long range models looking even further ahead predict colder than normal temperatures to last through the first half of the month.

Below is time lapse video from our webcams capturing last night’s storm.  Each take 14 hours and compress them into 30 seconds.

Thornton snowstorm and news updates

Old Man Winter is staged to arrive in Colorado in a big way.  With snow and arctic cold set to arrive, the next 48 hours are going to be interesting and in fact, the cold looks to last through the weekend.

For all the latest with the storm, be sure to check our Winter Weather Briefing page.

We will be providing updates as needed on our Google+ and Facebook pages as well.  We realize however that many folks don’t belong to those social networks.  You can follow along instead using the embedded Facebook ticker below if that is the case.

  • Remember, when the snow starts flying, stay up to date with ThorntonWeather.com: ‘Like’ us on Facebook, follow us on Twitter and add us to your Google+ circles

A look ahead at Thornton’s December weather

Thornton's December Weather Preview
December ranks as Denver's coldest and third snowiest month.

As with any month in the Denver area, December can bring a variety of conditions. Certainly we have seen bitter cold and heavy snow but in other years dry and mild conditions prevailed.

Based on the updated 1981 to 2010 averages from the National Weather Service, the month is actually our coldest of the year. It also is our third snowiest behind March and November.

Winter weather is typically what we think of when we think about December and it is indeed prone to winter extremes.

In fact, our coldest month in Denver history was in December 1983.  In terms of snow, our snowiest month ever occurred in December 1913.  More recently the Christmas Eve Blizzard of 1982 and the storms on December 2006 invoke snow-filled memories.

You can read much more about our historical December weather as well as get a preview of what we can expect in 2012 here in our complete story.

Remember, when the snow starts flying, stay up to date with ThorntonWeather.com: ‘Like’ us on Facebook, follow us on Twitter and add us to your Google+ circles

Thornton’s December 2010 weather wrap – Month ends drier and warmer than normal again

Thornton's December 2010 Weather Wrap
Thornton wraps up December with another drier and warmer than normal month.

Much to our dismay we closed out December the same way we did the month prior – warmer and drier than average.  Snowfall continues to elude us this season as we have recorded a mere 4.8 inches thus far which is 20.8 inches below normal.

For the month of December the story was the precipitation, or rather the lack thereof.  A mere 0.22 inch was officially recorded at Denver International Airport and Thornton was only slightly better at 0.28 inch.  This is far below the normal of 0.63 inch for Denver. 

The majority of that precipitation was during the last two days of the month when a very cold and quick snowstorm moved through Colorado.  Were it not for that Denver would have wrapped up the month as the 2nd driest December on record.  Instead the little bit of precipitation that was recorded dropped it out of ‘top 10 driest’ consideration. 

The snow that did fall on the 30th and 31st did not amount to a lot – officially 3.3 inches at DIA.  Thornton was only slightly better with 3.8 inches.  This is again far below the historical average of 8.7 inches for December. 

Continue reading Thornton’s December 2010 weather wrap – Month ends drier and warmer than normal again