Category Archives: Thornton Weather

February 14 to February 20 – This week in Denver weather history

February 14 to February 20 - This week in Denver weather history
February 14 to February 20 - This week in Denver weather history

Many notable weather events have occurred in Denver this week in the past, some recently.  It was just last year that a windstorm knocked down trees and powerlines in Boulder.  Three years ago, we saw an end to 61 days straight with snow cover – the second longest streak in Denver history.

13-14

In 1895…a cold air mass settled over the city.  High temperatures of only 4 degrees on the 13th and 8 degrees on the 14th were record low maximum temperatures for each day.  Low temperatures were 6 degrees below zero on the 13th and 5 degrees below zero on the 14th…but were not records.  Light snow totaled only 0.4 inch.  Winds were light.
 
In 1960…snowfall totaled 6.1 inches and north-northwest winds gusted to 39 mph at Stapleton Airport.
 
In 1967…high winds were widespread along the foothills where wind gusts of 60 to 90 mph were common.  A wind gust to 108 mph was measured at the National Center for Atmospheric Research in Boulder.  Sustained winds of 50 to 55 mph with gusts as high as 70 mph were recorded in downtown Boulder. An estimated 3 thousand dollars in damage occurred to mobile homes in Boulder.  Power lines were downed over a wide area.  At Stapleton International Airport…west winds gusted to 32 mph on the 13th and southwest winds gusted to 48 mph on the 14th.
 
In 1972…winds gusted to 67 mph at the National Bureau of Standards in Boulder.  Wind gusts to 49 mph were measured in downtown Boulder.  West winds gusted to 26 mph at Stapleton International Airport.
 
In 2001…heavy snow fell across metro Denver and in the foothills.  Snowfall totals included:  8 inches at Evergreen; 7 inches atop Crow Hill and in Lakewood; 6 inches in Denver…Doubleheader…Eldorado Springs… Morrison…and Pine Junction.  Snowfall totaled 4.8 inches at the site of the former Stapleton International Airport. Northeast winds gusted to 33 mph at Denver International Airport on the 13th.

14  

In 1918…southwest winds were sustained to 41 mph with a measured extreme velocity to 46 mph.
 
In 1987…metro Denver received only 3 to 4 inches of snow… But the foothills west of Boulder received up to 11 inches of snow.  Snowfall totaled 4.2 inches at Stapleton International Airport where north winds gusted to 31 mph.
 
In 1988…winds gusted to 81 mph at Echo Lake.
 
In 2002…high winds developed in the Front Range foothills during the early morning hours.  Winds gusted to 84 mph… 11 miles north of central city.  West winds gusted to 43 mph at Denver International Airport.
14-15 in 1960…heavy snowfall totaled 6.1 inches at Stapleton Airport.
 
In 1965…5.4 inches of snow fell at Stapleton International Airport behind a cold front.  North-northeast winds gusted to 32 mph.  Winds were strong and gusty all day and caused considerable blowing snow…contributing to hazardous driving conditions mainly to the east of Denver.
 
In 1984…a snow and wind storm howled across eastern Colorado closing I-70 east of Denver.  This was the second blizzard in less than 4 days.  Only 0.5 inch of new snow fell at Stapleton International Airport…but north winds gusted to 51 mph.

Continue reading February 14 to February 20 – This week in Denver weather history

2010 storm spotter training dates announced

Last year's "Summer of Storms" should serve as a reminder of the severe weather threat in Denver.
Last year's "Summer of Storms" should serve as a reminder of the severe weather threat in Denver.

Remember last year’s “Summer of Storms” that saw a seemingly endless parade of hail, funnel clouds and tornadoes visit the Front Range?  The severe weather threat in Colorado is real and it can turn deadly in an instant. 

Education is key to knowing how to protect you and your family.  Whether you want to be an official storm spotter or maybe just want to learn more about severe weather, storm spotter training can provide you an incredible opportunity to learn. 

The National Weather Service Denver / Boulder office has announced a series of storm spotter training dates for Colorado for the 2010 season. 

The storm spotter program is a nationwide program with more than 280,000 trained spotters.  These volunteers report weather hazards to their local National Weather Service office providing vital information when severe strikes.  Data from spotters include severe wind, rain, snow measurements, thunderstorms and hail and of course tornadoes. 

Storm spotters are part of the ranks of citizens who form the Nation’s first line of defense against severe weather. There can be no finer reward than to know that their efforts have given communities the precious gift of time–seconds and minutes that can help save lives.

By completing one of these training classes you can become an official storm spotter.  When severe weather strikes, you can report it by calling a special toll free number or submit your report via the National Weather Service’s website.

These are great sessions for anyone wanting to learn more about the severe weather we experience in Colorado, whether you want to be an official spotter or not.  All training is free.  Topics include:

  • Basics of thunderstorm development
  • Fundamentals of storm structure
  • Identifying potential severe weather features
  • Information to report
  • How to report information
  • Basic severe weather safety

To learn more about the program, see here: http://www.crh.noaa.gov/bou/awebphp/spotter.php

Below are the dates, times and locations announced thus far.  There is one this coming weekend in north Denver, two in Westminster in March and one in Commerce City in April – all are great opportunities for Thornton residents.  Click here to go to the NWS site for the latest.

 
February, 2010 – Upcoming
Day City, State Time Location
14 Denver, CO(Denver County) 1:00pm MST note: Following National Storm Chaser conference.
There is a charge for the conference, spotter training is free.
Red Lion Hotel Central
4040 Quebec Street
Denver, CO 80216
  Contact Information: Robert.Glancy@noaa.gov
 
March, 2010 – Upcoming
Day City, State Time Location
08 Holyoke, CO(Philllips County) 10:00am MDT Phillips County Fairgrounds
Event Center
Holyoke, CO
  Contact Information: philcoadmin@pctelcom.coop
08 Julesburg, CO(Sedgwick County) 6:00pm MST Julesburg Fire Department
  Contact Information: sedgwickcooem@yahoo.com
09 Haxtun, CO(Phillips County) 6:30pm MST Haxtun Volunteer Fire Dept.
  Contact Information: jdavis@pctelcom.coop
16 Westminster, CO(Adams County) 2:30pm MDT Front Range Community College
3645 West 112th Ave.
room TBD
Westminster, CO 80031
  Contact Information: Robert.Glancy@noaa.gov
16 Westminster, CO(Adams County) 6:30pm MDT Front Range Community College
3645 West 112th Ave.
room TBD
Westminster, CO 80031
  Contact Information: Robert.Glancy@noaa.gov
29 Sterling, CO(Logan County) 6:30pm MDT Sterling Fire Department
420 Oak Street
Sterling, CO
  Contact Information: Owens@Sterlingcolo.com
31 Akron, CO(Washington County) 6:30pm MDT rescheduled…
Washington County Fairgrounds Event Center, Akron
  Contact Information: mmccaleb@co.washington.co.us
 
April, 2010 – Upcoming
Day City, State Time Location
01 Anton, CO(Washington County) 6:30pm MDT Southwest Washington VFD, Anton station
  Contact Information: mmccaleb@co.washington.co.us
06 Agate, CO(Elbert County) 6:30pm MDT Agate School.
  Contact Information: cory.stark@elbertcounty-co.gov
08 Fort Morgan, CO(Morgan County) 7:00pm MDT TBD
  Contact Information: senfante@co.morgan.co.us
15 Castle Rock, CO(Douglas County) 6:30pm MDT TBD
  Contact Information: fsantaga@dcsheriff.net
23 Commerce City, CO(Adams County) 1:00pm MDT 4201 East 72nd Avenue
Commerce City, CO
  Contact Information: RNewman@co.adams.co.us
29 Parker, CO(Douglas County) 7:00pm MDT South Metro Fire Parkglenn HQ
10235 Parkglenn Way
Room A & B
Parker, CO
  Contact Information: kc0mht@msn.com

February 7 to February 13 – This week in Denver weather history

February 7 to February 13 - This week in Denver weather history
February 7 to February 13 - This week in Denver weather history

You can tell how eventful a week in Denver weather history is by the length of these articles and this one is a long one for sure.  In history we have seen Arctic cold, spring-like warmth, major snowstorms and blizzards and hurricane force winds.  There is even a rare thunderstorm that dropped a bit of hail.

30-7

In 1985…a cold front on the 29th produced a protracted cold spell as arctic air remained entrenched across metro Denver. While the only daily temperature record set was a low maximum reading of 2 degrees on February 3rd…minimum temperatures plunged well below zero on 9 consecutive days. The coldest readings were 15 degrees below zero on January 31st and 14 degrees below zero on February 5th.

31-8

In 1963…warm weather that began with the strong Chinook winds on the 31st and 1st continued through the 8th. Maximum temperatures through the period ranged from 52 degrees on the 2nd to 76 degrees on the 5th…which was a new record high for that date.

31-12

In 1899…a protracted cold spell lasted almost two weeks. Low temperatures plunged below zero on all days but February 9th with a reading of 6 degrees.  The coldest low temperature of 22 degrees below zero on February 6th was a record low for the date.  Low temperatures of 20 degrees below zero occurred on both February 11th and 12th… But only the 11th remains as the record minimum for the date.  High temperature of only 5 degrees below zero on February 11th was a record low maximum for the date.  High temperatures climbed to only zero degrees on both February 2nd and 3rd…but were not records.  Intermittent light snow or flurries fell during the period.  The most snowfall…2.0 inches…occurred on February 2nd.

1-9

In 1883…a protracted cold period occurred when low temperatures dipped below zero for 9 consecutive days. Low temperatures ranged from 22 degrees below zero on the 4th to 2 degrees below zero on the 1st and 6th.  High temperatures ranged from 10 below zero on the 3rd to 23 on the 9th.  Several temperature records were set that still stand today.  Record lows of 18 below and 22 below zero occurred on the 3rd and 4th.  Record low maximum readings of 2 below and 10 below zero occurred on the 2nd and 3rd.  The high of only 10 below zero on the 3rd is the coldest maximum temperature ever recorded in Denver.

5-11

In 1978…the 5th marked the start of a record 7 consecutive days of dense fog at Stapleton International Airport.  The heavy fog reduced the visibility to 1/4 mile or less for a period of time on each of these days.  Light snow and/or freezing drizzle occurred on most days.  Fog reducing visibility to less than 7 miles was recorded at Stapleton International Airport on 11 consecutive days through the 15th.  During the period 5-14…the cold thick fog deposited heavy rime ice up to 5 inches thick on power lines and poles over a wide area of eastern Colorado…causing a major electrical power outage disaster.

Continue reading February 7 to February 13 – This week in Denver weather history

A preview of Denver & Thornton’s February weather

February comes and serves as a bit of a month of transition between winter and spring. Average temperatures start to climb and things are generally pretty quiet.

However, it is still winter and below freezing temperatures at night still remain the norm. February is not typically a snowy month – in fact only the 6th snowiest – with an average of 6.3 inches. In terms of severe weather, the month joins September and October as being the quietest for Denver.

As we say though, it is a month of transition and as such extremes can and have occurred in the past. From severe cold and snow to beautiful spring-like days we can see it all. Oftentimes the month can lull us into a false sense of spring when the snowiest month – March – has yet to come.

Get all the details complete with historical extremes, statistics, and more in our complete preview here.

January 31 to February 6 – This week in Denver weather history

January 31 to February 6 - This week in Denver weather history
January 31 to February 6 - This week in Denver weather history

Winds can be a blessing and a curse this time of year.  Chinook winds can help warm what is otherwise a normally chilly season.  They can also cause a great deal of damage as they pick up speed as they come roaring across the Front Range.  While we have been lucky thus far this year and not had damaging wind events, looking back at this week in Denver weather history one can’t help but think that maybe it is just a matter of time before they strike.

26-1 

In 1888…a protracted warm spell lasted a week.  Maximum temperatures ranged from 62 degrees on the 29th to an all time record high for the month of 76 degrees on the 27th.  Daily record high temperatures of 76…69…and 71 occurred on the 27th…28th…and 30th respectively. Record high minimum temperatures of 47 and 34 occurred on the 26th and 27th.

27-31

In 1951…a major storm dumped 10.1 inches of snowfall at Stapleton Airport.  Most of the snow…8.3 inches…fell on the 29th.  Cold arctic air accompanied the snow.  Several temperature records were set…including record low maximum temperatures of 4 on the 28th and 4 below zero on the 29th and record low temperatures of 12 below zero on the 29th and 24 below zero on the 31st.  Temperatures were below zero for 45 consecutive hours.

29-31

In 1883…a major winter storm dumped 19.3 inches of snow on downtown Denver.  Most of the snow…12.2 inches…fell on the 31st.  This was the heaviest snowfall to hit the city in years.  Temperatures plunged from a high of 52 degrees on the 29th to a low of 13 degrees on the 31st. Precipitation from the storm totaled 2.23 inches.  The 1.22 inches of precipitation on the 31st was the greatest calendar day and 24 hour precipitation ever recorded in the city during the month of January.

30-31

In 1908…an apparent strong cold front plunged temperatures 45 degrees in 24 hours from 47 degrees at noon on the 30th to only 2 degrees at noon on the 31st.  North winds were sustained to 30 mph on the 30th.  Snowfall was only 0.8 inch on the 31st.
 
In 1965…a major storm dumped 10.4 inches of snow over metro Denver.  After 5 inches of snow fell in Boulder… Strong Chinook winds developed…warming the temperature 25 degrees in 90 minutes.  Wind gusts to 97 mph were recorded on Table Mountain in Boulder.  Winds gusts to 53 mph were measured in downtown Boulder where some damage occurred.  Minor wind damage also occurred in western suburbs of Denver.  West winds gusted to 51 mph at Stapleton International Airport on the 31st.
 
In 2005…a winter storm brought heavy snow to the Front Range foothills.  Storm totals included:  17 inches at Aspen Springs…13 inches 7 miles southwest of Boulder and at Lake Eldora…12.5 inches near Blackhawk…11.5 inches at Rollinsville and near Nederland…11 inches near Evergreen and Golden and at Gross Reservoir…and 10 inches at Cabin Creek.  Lesser amounts of snow fell over the city.  Only 1.9 inches of snow were measured overnight at Denver Stapleton.  North winds gusted to 30 mph at Denver International Airport…where freezing fog during the early morning of the 30th reduced the surface visibility to as low as 1/8 mile.  Light rainfall… Rare in January…totaled 0.06 inch at Denver Stapleton on the early morning of the 30th.

30-7

In 1985…a cold front on the 29th produced a protracted cold spell as arctic air remained entrenched across metro Denver. While the only daily temperature record set was a low maximum reading of 2 degrees on February 3rd…minimum temperatures plunged well below zero on 9 consecutive days. The coldest readings were 15 degrees below zero on January 31st and 14 degrees below zero on February 5th.

Continue reading January 31 to February 6 – This week in Denver weather history

January 24 to January 30 – This week in Denver weather history

January 24 to January 30 - This week in Denver weather history
January 24 to January 30 - This week in Denver weather history

Denver and Colorado weather is rarely boring.  This week in Denver weather history we see numerous occurrences of Chinook winds that warmed temperatures but also arrived with such force that they caused a great deal of damage.  We also see unseasably warm weather, bitter Arctic cold, and snow fall that had to be measured in feet.

18-24

In 2005…a week of mid-winter unseasonably warm weather pushed high temperatures into the 60’s or more on all but one day.  During the period…the highest temperature of 70 degrees on the 20th was a new record maximum for the date.  Low temperatures remained above freezing on 4 of the days.

22-26

In 1948…the longest period of snowfall on record (92 hours and 3 minutes) occurred in downtown Denver where a total of 13.6 inches of snow fell.  At Stapleton Airport…19.0 inches of snow fell…making it the heaviest snow in January and the 5th heaviest snow of record at that time.  North winds were sustained to a velocity of 23 mph on the 25th…but generally the winds were light throughout the storm.  The snow disrupted traffic…but street clearing was begun soon after it became apparent that the snow would be heavy.  Over the 5 days…temperatures ranged from a high of 48 degrees on the 22nd to a low of 1 degree on the 26th.  Most readings were in the teens and 20’s during the storm.

23-24

In 1921…heavy snowfall in downtown Denver totaled 8.0 inches overnight.  Northwest winds were sustained to 22 mph with gusts to 25 mph on the 24th.

24 

In 1887…west winds sustained to 44 mph warmed the temperature to a high of 56 degrees in the city.
 
In 1890…northwest winds sustained to 48 mph with gusts to 60 mph warmed the temperature to a high of 63 degrees.
 
In 1900…west winds were sustained to 44 mph with an extreme velocity of 46 mph.  The Chinook winds warmed the temperature to a high of 57 degrees.
 
In 1934…a trace of snowfall resulted in precipitation of 0.01 inch in downtown Denver.  This was the only measurable amount of precipitation for the month…making the month one of the driest January’s on record.
 
In 1956…west-northwest winds gusted to 51 mph at Stapleton Airport.  Strong and gusty winds persisted throughout the day.
 
In 1972…a west wind gust to 92 mph was recorded in Boulder at the National Bureau of Standards…while in downtown Boulder a wind gust to only 66 mph was measured.

In Denver…a car was demolished when the wind blew a traffic light pole onto it…and a wooden wall at a construction site was blown over damaging two cars.  Northwest winds gusted to 55 mph at Stapleton International Airport.
 
In 1982…strong winds were again reported along the eastern foothills.  While the most damage occurred in the Fort Collins area…Boulder did not entirely escape.  Nine planes were damaged at the Boulder airport along with 4 mobile homes and many cars in the Boulder area.  A school in Central City was damaged.  A water tank in Parker collapsed.  The strongest wind gust recorded was 140 mph at Wondervu.  Wind gusts reached 92 mph in Boulder. Northwest wind gusts to 61 mph were recorded at Stapleton International Airport.
 
In 1992…for the third day…high winds raked the eastern foothills.  Winds gusted to 105 mph at the National Center for Atmospheric Research in Boulder.  Several tractor trailers were overturned along State Highway 93…between Boulder and Golden.  Traffic lights and signs were knocked down in Boulder.  Other wind reports included:  86 mph at Rocky Flats…100 mph on Fritz Peak near Rollinsville…and 93 mph in north Boulder.  West winds gusted to 37 mph at Stapleton International Airport.

Continue reading January 24 to January 30 – This week in Denver weather history

January 17 to January 23 – This week in Denver weather history

January 17 to January 23 - This week in Denver weather history
January 17 to January 23 - This week in Denver weather history

Chinook winds in January oftentimes bring welcome warmth to the Front Range.  They can however be more of a curse than a blessing as at times they can reach hurricane strength and do extensive damage.  Looking back at this week in Denver weather history, we see many such occurrences. 

14-21

In 1930…a protracted cold spell occurred when low temperatures plunged below zero on 8 consecutive days.  The coldest low temperatures of 20 degrees below zero on the 17th and 19 degrees below zero on the 16th were record minimums for the dates.  High temperatures during the period ranged from 18 on the 18th to zero on the 20th.  Two degrees on the 15th was a record low maximum temperature for the date.

15-23

In 1962…a protracted cold spell kept metro Denver in the deep freeze for more than a week.  From the 15th thru the 23rd…low temperatures were zero or below for 9 consecutive days…but a daily record low was set only on the 22nd when the temperature dipped to 14 degrees below zero.  A record low maximum for the date was also set on the 22nd when the temperature climbed to only 11 degrees.  The coldest high temperature was 3 degrees above zero on the 21st…which did not break the record.  The protracted cold was broken for only a few hours on the afternoon of the 20th when Chinook winds warmed the temperature to a high of 38 degrees before another surge of cold arctic air plunged temperatures back into the deep freeze that evening.  The severe cold caused much damage to water systems.  A woman was frozen to death at Morrison.  There were other deaths attributable to the weather…including traffic deaths and heart attacks from overexertion.

16-17

In 1886…a brief cold spell resulted in two temperature records.  High temperatures of zero degrees on the 16th and 2 degrees below zero on the 17th were both record low maximums for the dates.  Low temperatures of 8 degrees below zero on the 16th and 16 degrees below zero on the 17th were not records.
 
In 1930…temperatures plunging well below zero resulted in two records.  Low temperatures of 19 degrees below zero on the 16th and 20 degrees below zero on the 17th were record low temperatures for the dates.  High temperatures were 4 degrees on the 16th and 15 degrees on the 17th.  Light snowfall totaled 4.0 inches.  North winds were sustained to 18 mph on the 16th.
 
In 1964…high winds struck the eastern foothills.  Gale velocity winds were recorded in Boulder with gusts to 83 mph measured at Rocky Flats.  Several airplanes were damaged at the Jefferson County Airport in Broomfield. Roofs…walls…and parts of buildings were blown away at various locations.  Power poles and trees were blown over.

16-18

In 1943…light snowfall totaled 3.2 inches over the 3 days. This was the only measurable snow of the month.  North winds were sustained to 20 mph on the 16th.

Continue reading January 17 to January 23 – This week in Denver weather history

January 10 to January 16 – This week in Denver weather history

January 10 to January 16 - This week in Denver weather history
January 10 to January 16 - This week in Denver weather history

January weather is like the weather of any other month in Denver  in that you can see just about any type of condition possible.  However, three conditions are dominant during the month – wind, snow and cold.  All three make many appearances in our look back at this week in Denver weather history.

From the National Weather Service:

7-10

In 1962…a major winter storm dumped 13.5 inches of snow on metro Denver.  A foot of the snow fell on the 8th when northeast winds gusted to 30 mph.  The storm was followed by an intense blast of very cold arctic air.  Minimum temperature readings of 24 degrees below zero occurred on both the 9th and 10th.  The temperature never reached above zero on the 9th when a maximum reading of 1 degree below zero was recorded.  Temperatures were below zero for 37 consecutive hours.

8-10

In 1983…winds of 70 to 90 mph howled through Boulder. A wind gust to 100 mph was recorded on Fritz Peak near Rollinsville.  A tree blown down by the wind damaged a house in eastern Boulder County.  The strong winds developed behind a cold front late on the 8th and continued through the 10th.  At Stapleton International Airport…west to northwest winds gusted to 49 mph on the 8th…to 45 mph on the 9th…and to 48 mph on the 10th.

9-10

In 1962…the low temperature plunged to 24 degrees below zero on both days.
 
In 1972…a west wind gust to 60 mph was recorded at Stapleton International Airport…while in Boulder a wind gust to 86 mph was recorded at the National Bureau of Standards. The roof of a house was blown off…and trees were blown down in Boulder.  The high winds contributed to the damage from a building fire in Boulder.
 
In 2000…heavy snow and strong winds in the mountains spilled into the Front Range foothills.  Ward…northwest of Boulder…received 9 inches of new snow.  Wind gusts to 91 mph were measured in Golden Gate Canyon…with gusts to 77 mph at Loveland Ski Area and to 73 mph along State Highway 93 north of Golden.  West winds gusted to 44 mph at Denver International Airport on the 9th.

10 

In 1893…strong west winds in Boulder and the adjacent foothills caused only minor damage.

In Denver…northwest winds were sustained to 48 mph with gusts as high as 60 mph.  The Chinook winds warmed the temperature to a high of 64 degrees and a low of only 40 degrees…which was a record high minimum for the date.
 
In 1911…southwest Chinook winds sustained to 44 mph warmed the temperature to a high of 60 degrees.
 
In 1932…the first thunderstorm ever officially recorded in Denver during January occurred in the early morning. The assistant observer heard two prolonged peals of thunder between 4:20 am and 4:25 am.  Another off-duty observer was awakened by the thunder.  Other people reported both thunder and lightning.  Light snow was falling at the time.  Pellets of graupel or hail were reported from some parts of the city.  Snowfall totaled only 1.8 inches.  Northwest winds gusted to 30 mph.
 
In 1962…as the temperature dipped to a frigid 24 degrees below zero…setting a new record minimum for the date… The pressure adjusted to sea level reached the highest ever recorded in Denver…31.24 inches (1057.8 mb).  The altimeter setting reached 30.70 inches…and the actual station pressure recorded was 25.260 inches.
 
In 1988…strong winds occurred throughout the day in and near the foothills.  Peak gusts to 85 mph were recorded at Rollinsville…84 mph at Echo Lake…and 64 mph in Boulder.
 
In 1990…a third consecutive day of 50 to 85 mph wind gusts occurred in and along the eastern foothills.  A 5 mile portion of the Denver-Boulder turnpike was closed after clouds of blowing dust and gravel caused several multicar accidents near Broomfield.  One 59-year-old woman was killed and two others injured.  A wind gust to 81 mph was recorded at the nearby Jefferson County Airport.

In Boulder…wind gusts to 85 mph were blamed for ripping off a portion of a roof on a house…as well as blowing out the large picture window.  West winds gusted to 41 mph at Stapleton International Airport.  The warm Chinook winds set a record high temperature of 71 degrees in Denver for the date.
 
In 1996…strong northwest winds developed behind a pacific cold front that moved rapidly across northeast Colorado. A peak wind gust to 64 mph was recorded at the Rocky Flats Environmental Test Facility in Jefferson County.  North- northeast winds gusted to 38 mph at Denver International Airport.

Continue reading January 10 to January 16 – This week in Denver weather history

December 2009 goes into the books as seventh coldest on record

For the second time in the past three months, Denver has experienced monthly average temperatures in the ‘top 10 coldest’ category. In October, the Mile High City saw its second coldest October on record since record keeping began in 1882. Now Denver has just wrapped up its seventh coldest December in history.

Denver’s average December 2009 temperature was 24.1 degrees – a chilly 6.2 degrees below the normal average of 30.3 degrees. That puts the month into the books as the seventh coldest December on record (image right).  Thornton was just a touch colder having recorded an average temperature of 23.8 degrees.

Temperatures during the month ranged from a high temperature of 59 degrees on the 1st down to a low of -17 on the 9th. Overall, the majority of days during the month saw below normal temperatures.

In terms of snowfall, the month did finish above average but not in record setting territory. The National Weather Service recorded 11.1 inches of snowfall at the official monitoring station at Denver International Airport. This was 2.4 inches above the average of 8.7 inches for December.  In Thornton, we received a bit more snow than DIA.  15.3 inches was recorded at ThorntonWeather.com of which the single biggest even was the pre-Christmas storm which dumped 7.5 inches.

 The snow we did receive however was rather dry and as such we finished the month below normal for precipitation. DIA recorded 0.45 inch of precipitation which is 0.18 inch below normal.  Here again, because of the additional snowfall, Thornton fared a bit better with 0.5 inch of precipitation. 

CLIMATE REPORT
NATIONAL WEATHER SERVICE BOULDER, CO                                 
510 PM MST SAT JAN 2 2010

................................... 

...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF DECEMBER 2009...

CLIMATE NORMAL PERIOD 1971 TO 2000
CLIMATE RECORD PERIOD 1872 TO 2009

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            59   12/21        79     -20       69  12/02       
                        12/01                                         
LOWEST            -17   12/09       -25       8      -19  12/15       
AVG. MAXIMUM     36.4              44.1    -7.7     41.0              
AVG. MINIMUM     11.9              16.4    -4.5     12.3              
MEAN             24.1              30.3    -6.2     26.6              
DAYS MAX >= 90      0               0.0     0.0        0              
DAYS MAX <= 32     15               5.3     9.7       10              
DAYS MIN <= 32     31              29.2     1.8       30              
DAYS MIN <= 0       6               2.8     3.2        6              

PRECIPITATION (INCHES)
RECORD
 MAXIMUM         5.21   1913                                          
 MINIMUM         0.00   1881                                          
TOTALS           0.45              0.63   -0.18     0.24              
DAILY AVG.       0.01              0.02   -0.01     0.01              
DAYS >= .01         7               5.3     1.7        6              
DAYS >= .10         2                MM      MM        0              
DAYS >= .50         0                MM      MM        0              
DAYS >= 1.00        0                MM      MM        0              
GREATEST
 24 HR. TOTAL    0.20   12/22 TO 12/23        0.10  12/13 TO 12/14       

SNOWFALL (INCHES)
RECORDS
 TOTAL           57.4   1913  SNOWIEST DENVER MONTH SINCE 1881
TOTALS           11.1                8.7              7.1             

DEGREE_DAYS
HEATING TOTAL    1260              1078     182     1179              
 SINCE 7/1       2739              2486     253     2367              
COOLING TOTAL       0                 0       0        0              
 SINCE 1/1        533               696    -163      825              

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

WIND (MPH)
AVERAGE WIND SPEED              8.8
RESULTANT WIND SPEED/DIRECTION   3/217
HIGHEST WIND SPEED/DIRECTION    43/220    DATE  12/13
HIGHEST GUST SPEED/DIRECTION    49/220    DATE  12/13

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM *SUNSHINE DATA N/A EFFECTIVE 10/1

NUMBER OF DAYS FAIR            4
NUMBER OF DAYS PC             21
NUMBER OF DAYS CLOUDY          6

AVERAGE RH (PERCENT)     61

WEATHER CONDITIONS. NUMBER OF DAYS WITH 
THUNDERSTORM              0     MIXED PRECIP               0
HEAVY RAIN                0     RAIN                       0
LIGHT RAIN                0     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                0     SNOW                       2
LIGHT SNOW               10     SLEET                      0
FOG                      11     FOG W/VIS <= 1/4 MILE      1
HAZE                      7                                           
                                                                    
-  INDICATES NEGATIVE NUMBERS.                                      
R  INDICATES RECORD WAS SET OR TIED.                                
MM INDICATES DATA IS MISSING.                                       
T  INDICATES TRACE AMOUNT.   

January 3 to January 9 – This week in Denver weather history

January 3 to January 9 - This week in Denver weather history
January 3 to January 9 - This week in Denver weather history

January weather in Colorado can be as varied as during any month of the year.  Temperatures bordering on spring-like to bone chilling Arctic cold can be seen.  Snow of course plays a big part and while not always recognized as a big danger, high speed damaging winds are not unusual.

31-6

In 1973…the 31st marked the start of a protracted cold spell that extended into January of 1974 when temperatures dipped below zero on 7 consecutive days.  Record daily minimum readings occurred on the 3rd and 5th when the temperature plunged to 17 degrees below zero on both days. A record low daily maximum temperature of only 4 degrees occurred on the 5th.

31-7 

In 1941…a protracted cold spell through January 7…1942… Produced below zero low temperatures on 7 of the 8 days. A low temperature of 2 degrees on the 3rd prevented a string of 8 days below zero.  The coldest days during the period were the 1st with a high of 2 degrees and a low of 9 degrees below zero…the 4th with a high of 2 degrees and a low of 11 degrees below zero…and the 5th with a high of 26 degrees and a low of 12 degrees below zero.

1-5  

In 1940…the first days of the month were characterized by a mixture of drizzle…light snow…and fog.  Fog occurred on each day.  On the 4th and 5th considerable glazing resulted from freezing drizzle.  All objects were coated with a glaze on the windward side.  This resulted in very slippery streets…which caused several minor traffic accidents.  The glaze was not heavy enough to damage wires and cables.

2-3  

In 1971…a major storm dumped a total of 8.4 inches of snow at Stapleton International Airport where north winds gusted to 23 mph.
 
In 1972…a strong cold front late on the 2nd produced north wind gusts to 35 mph at Stapleton International Airport. Snow…heavy at times on the 3rd…totaled 6.4 inches as temperatures hovered only in the single digits.
 
In 2000…heavy snow fell over the higher terrain of the palmer divide to the south of metro Denver.  Snowfall totaled 7 inches 5 miles southwest of Sedalia.  Only 1.5 inches of snowfall were measured at the site of the former Stapleton International Airport.

2-4

In 1949…the worst blizzard in many years struck metro Denver and all of northern Colorado.  The storm produced blizzard conditions with wind gusts of 40 to 50 mph all day on the 3rd when temperatures were only in the single digits.  This resulted in extremely cold wind chill temperatures of 40 to 55 degrees below zero.  Stapleton Airport received 13.3 inches of snow from the storm… While downtown Denver received 11.8 inches.  The snow fell for 51 consecutive hours downtown.  Numerous lives were lost…and livestock losses were high across the northeastern plains of Colorado where extensive airlift operations were needed to bring supplies and food to isolated communities.

Continue reading January 3 to January 9 – This week in Denver weather history