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.
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.
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.
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.
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…
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
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 - 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)
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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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.
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!
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.
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.
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.
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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.
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 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.
A Winter Storm Warning for snow and blowing snow will be in effect for Thornton. Click the image to view our Winter Weather Briefing page. (National Weather Service)
Update, 1:10pm – A lull in the storm. Snow will taper off for just a little bit this afternoon before picking back up before rush hour.
A Winter Storm Warning remains in effect and the National Weather Service is forecasting 5 to 10 inches total accumulation of snow. In Thornton we have recorded 1/2 inch so far and in the end we will likely be at the lower end of the forecast range. Click here to view the latest storm reports.
As expected the real story is the temperatures. Thornton hit its high temperature today of 32.5 degrees at 1:52am and it has all been downhill from there. With winds around 10 mph gusting to 20 mph wind chills have now dipped into the single digits.
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Original story, 7:25am – The snow and cold are running a bit behind but they are on their way. Thornton and the rest of the Denver metro are set to get our first winter storm of the season and a Winter Storm Warning has been issued.
A Winter Storm Warning for snow and blowing snow will go into effect for the Denver metro area at 9:00am and run through 6:00am on Friday. The storm system is pushing its way through northeastern Colorado and as it does temperatures will plummet and snow will begin to fall.
Look for the snow to gradually start this morning with the heaviest period being late this afternoon and into tonight. Total snow accumulations in Denver are forecast to be in the 5 to 10 inch range. Here in Thornton we will likely be on the lighter side of that range. The Front Range foothills and Palmer Divide may see up to a foot.
The snow that initially falls will likely melt due to the warm ground however as temperatures drop roads will become icy and slick. Extreme caution should be used, particularly late this afternoon and into tonight.
While we are looking at a decent bit of snowfall, there isn’t a lot of moisture in this system. As a result look for the snow to be light and fluffy. This will make it easy to shovel but when winds pick up it creates a blowing snow hazard and visibility may be impacted.
This sets the stage for near blizzard conditions, particularly in open areas to the northeast. The National Weather Service has indicated a Blizzard Warning may be issued in some areas later today if conditions warrant.
Temperatures are the other big aspect of this storm system. The mercury will be dropping throughout the day and by 5:00pm it will be down to 14 degrees with overnight lows approaching zero.
The winds, coupled with the bitter Arctic cold, will create dangerous wind chill conditions. Late afternoon will see wind chills near zero and overnight they will dip to near 15 degrees below zero.
Anyone planning outdoor activities or traveling needs to be prepared. Ensure you have adequate clothing and emergency supplies. For more information be sure to check out our Winter Weather Preparedness links below.
Airlines and Colorado Department of Transportation prepare for storm
At Denver International Airport (DIA) airlines began waiving fees for passengers wanting to change their travel plans. Continental, United and Frontier all said they were expecting delays and possibly cancellations from the storm and were operating accordingly. Our Airport & Flight Status page has details.
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.
