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April 8 to April 14 – This Week in Denver Weather History

April 8, 2012 Thornton Weather Leave a comment

April in Denver can bring a wide array of weather conditions, many of which appear in their most extreme form. Our look back at this week in Denver weather history demonstrates this with everything from major snowstorms to damaging windstorms to even a tornado.

From the National Weather Service:

6-8

In 1973…a major spring snow storm dumped 11.6 inches of snowfall over metro Denver. North wind gusts of 30 to 35 mph produced some blowing snow. Most of the heavy wet snow… 10.1 inches…fell on the 7th when temperatures remained in the 20’s. Snow accumulated on the ground to a maximum depth of 9 inches. Low temperature of 5 degrees on the 8th was a new record minimum for the date and the lowest for so late in the season.

7-9

In 1913…heavy snowfall totaled 10.9 inches in downtown Denver behind a cold front. Most of the snow fell on the 8th. Northeast winds were sustained to 35 mph with gusts to 38 mph on the 9th.

In 1935…moderate dust blew into the city around 9:00 pm on the 7th and persisted until early afternoon on the 9th. Southeast winds were sustained to around 20 mph on the 7th and 8th. Winds shifting to the west at sustained speeds to 20 mph cleared the dust from the air on the 9th.

7-12

In 1959…snow falling over a 5-day period totaled 20 to 30 inches just east of the mountains…while over the plains blizzard conditions closed schools and blocked highways. The second big storm in two weeks dumped 16.4 inches of snowfall on Stapleton Airport with the most…11.6 inches… Occurring on the 8th. East winds gusted to 37 mph on the 9th. Temperatures dipped into the single digits on the mornings of the 7th and 12th when 7 degrees were registered. Low temperature records for the dates were set on the 9th…10th…and 12th. The cold temperatures caused streets to glaze with ice…resulting in the death of a pedestrian who was struck by a car in Denver. Three people died from heart attacks while shoveling the heavy… Wet snow.

In 1885…dense smoke polluted the air until noon.

In 1887…south winds were sustained to 42 mph.

In 1890…northwest winds were sustained to 48 mph with gusts as high as 60 mph.

In 2005…a mixture of strong pressure gradient winds coupled with thunderstorm outflow winds produced high winds across metro Denver. The high winds downed power lines and knocked out electricity to about 19 thousand customers on the east side of metro Denver. High wind reports included gusts to 68 mph in Longmont…61 mph near Castle Rock…59 mph at Centennial Airport…and 54 mph at Denver International Airport.

8-10

In 1999…a windstorm caused 20 million dollars in damage along the Front Range urban corridor from Fort Collins south to Pueblo and to the east over the plains…making the storm equal to the costliest windstorm ever…which occurred in Boulder on January 17…1982. In metro Denver… Several homes were damaged as shingles were blown off roofs. Large pieces of a roof torn off a strip mall in Lakewood damaged several cars in a parking lot. Most of the damage to homes consisted of broken fences…awnings…doors…and windows. Scores of automobiles suffered broken or cracked windshields and paint damage from flying debris. Multiple accidents were triggered as several tractor-trailer rigs were blown on their sides by the strong cross-winds. Blowing dust and dirt caused near zero visibilities at times. Both I-25 and I-76 were closed north and northeast of Denver. State Highway 93 was closed between Golden and Boulder. Several trees…power poles…and power lines were downed…causing a number of outages as well as sparking a few small grass fires. Highest wind gusts reached 112 mph atop Niwot Ridge near the Continental Divide west of Boulder…102 mph at Wondervu…100 mph at the National Center for Atmospheric Research mesa lab in Boulder…98 mph at the national wind technology center near Broomfield…96 mph on Rocky Flats…92 mph at Jefferson County Airport near Broomfield and on the University of Colorado campus in Boulder…and 90 mph at Highlands Ranch in southwest metro Denver. Winds gusted to 48 mph at Denver International Airport.

In 1950…strong southwest winds gusting to 58 mph reduced the visibility to 1 mile in blowing dust at Stapleton Airport. Scattered minor wind damage…consisting of falling tree branches and damage to signs…occurred across metro Denver.

In 1989…6 to 12 inches of snow fell at many locations in the Front Range foothills. Boulder received 6 to 8 inches. Five inches (5.0 inches) of snow fell at Stapleton International Airport…causing 2 hour flight delays. I-25 south of Denver was closed for 4 hours due to a 100- car traffic pileup. North winds gusted to 33 mph at Stapleton International Airport where the maximum snow depth on the ground was only 3 inches due to melting.

Continue reading April 8 to April 14 – This Week in Denver Weather History →

Thornton Weather

City of Thornton announces emergency alert system for residents

April 4, 2012 Thornton Weather 1 Comment

City of Thornton Emergency Management T-Alerts — The City of Thornton's new Emergency Management T-Alerts will inform residents of a wide variety of weather and civil emergencies.

Sitting at the western edge of tornado alley, the Denver metro area is home to severe weather of all forms. In an effort to keep residents aware of the dangers Mother Nature brings every year, the City of Thornton is set to roll out an email alert system.

It has been nearly 31 years since the most destructive tornado to strike the Denver area tore through the city of Thornton. In the intervening time between now and then, it is ironic that neither Thornton nor Adams County deployed any sort of alert system for its residents beyond Reverse 911.

Seeking to correct that lapse, Thornton’s Office of Emergency Management presented a significant enhancement to the city’s T-Alert system to city council at a planning session last night.

T-Alert is the existing email subscription system for Thornton residents that can keep them up to date with everything from traffic to trash services to recreational opportunities. Now, emergency management announcements will be added to the service.

Emergency Manager Gene Putman explained that with the proliferation of email on mobile devices like cellular phones, the system will allow the city to send out warnings to residents in a matter of seconds. The system was tested during the February snowstorms and was a resounding success.

Dispatches can be sent out by the city’s emergency management personnel or in an urgent situation, the new 911 center. Spanish translations to the messages will also be included in the emails.

Putman said, “Within 30 seconds of a warning being issued by the National Weather Service we can have that critical information out to residents.”

Uses for the emergency management service will include obvious items such as tornado watches and warnings and severe hail or flooding. Also thrown into the mix will be important announcements about major snow events, hazardous material spills and other types of civil alerts.

Don’t wait: Sign up for the City of Thornton’s Emergency Management Announcements here
PDF: City of Thornton Emergency Management Tmail Brochure

Jack Ethredge, City Manager, is no stranger to disasters having served as Emergency Manager along the Gulf Coast during two hurricanes. He told council the system gives the city an “important, broader way to communicate.”

While the new system will help to keep residents safe, officials also remind residents that they must take responsibility for their own safety as well and stay aware of developing weather. Local news media should be monitored and residents should own a NOAA All Hazards Radio.

Note: In addition to the city’s alert system, you can subscribe to ThorntonWeather.com’s alert system. We believe the two systems will complement each other. Our system provides all watches and warnings from the National Weather Service while the city’s will maintain a focus on the major events.

Thornton also continues to improve and refine its disaster preparedness as a city government.

Emergency management personnel are receiving important training on disaster response and new emergency procedures are being developed all city employees.

When disaster strikes, the speed and accuracy of a response is essential and Emergency Investigation Area Teams have been created to aid on this front. Each team will be comprised of personnel from key city departments. These teams will be responsible for one of six Emergency Investigation Areas and when needed, will be deployed to document a situation and provide direction.

Thornton Weather

March 2012 goes into the Denver weather history books on a number of marks

April 1, 2012 Thornton Weather Leave a comment

Record setting high temperatures in Thornton. — March 2012 goes into the history books as the driest, least snowiest and 2nd warmest March on record in Denver.

The month of March in Denver is typically known for its snow and corresponding chilly temperatures. That however was certainly not the case for March 2012 as the Mile High City saw one of its warmest and driest Marches on record.

From the start of the month to the end, March’s temperatures were well above normal. While we would normally see days with temperatures in the 50s, we instead saw 70s and even a couple of 80+ degree days.

The historical overall average temperature for the month of March is 40.4 degrees (based on 1981 to 2010 normals). March 2012’s average of 49.2 degrees was an astonishing 8.8 degrees above normal.

This sends the month into the record books as the second warmest March ever recorded in Denver. The number one spot is held by March 1910 which saw an average of 50.4 degrees.

Here in Thornton, we were actually slightly warmer than the official Denver measuring station at DIA. Our monthly average temperature came in at 49.6 degrees.

Individually, six days set or tied high temperature records for Denver:

74 degrees on March 13 which tied the old record of 74 set in 2007 and previous years
75 degrees on March 16 which broke the old record of 74 set just one year ago in 2011
76 degrees on March 17 which broke the old record of 75 set in 1974
76 degrees on March 23 which tied the old record of 76 set in 1967
75 degrees on March 25 which tied the old record of 75 set in 1998 and previous years
81 degrees on March 31 which broke the old record of 80 set in 1946

In terms of precipitation, March 2012 will now hold the marks for the driest and least snowiest on record.

The rain bucket at Denver International Airport saw a mere 0.03 inch of liquid precipitation. This was far below the average of 0.92 inch and easily puts March 2012 into the books as the number one driest March on record. The previous record holder was 1908 when 0.11 inch was recorded.

March is historically Denver’s snowiest month averaging 10.7 inches. This year the month only brought a trace of snow on three days. The previous least snowiest March occurred in 1883 when 0.3 inch of the white stuff was recorded.

Just like Denver, Thornton saw an extraordinary lack of snow and precipitation. We as well recorded 0.03 inch of precipitation but we did manage to record 0.40 inch of snow, all on the morning of the 2nd.

Click here to view the March 2012 climate summary for Thornton.

CLIMATE REPORT
NATIONAL WEATHER SERVICE BOULDER, CO
1026 AM MDT SUN APR 1 2012

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

...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF MARCH 2012... 

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              84   03/26/1971
 LOW              -11   03/28/1886
HIGHEST            81   03/31        84      -3       76  03/21
LOWEST             16   03/02       -11      27       14  03/05
AVG. MAXIMUM     65.5              54.4    11.1     58.7
AVG. MINIMUM     32.9              26.4     6.5     27.8
MEAN             49.2              40.4     8.8     43.3
DAYS MAX >= 90      0               0.0     0.0        0
DAYS MAX <= 32      0               1.9    -1.9        1
DAYS MIN <= 32     14              23.6    -9.6       24
DAYS MIN <= 0       0               0.1    -0.1        0

PRECIPITATION (INCHES)
RECORD
 MAXIMUM         4.56   1983
 MINIMUM         0.11   1908
TOTALS           0.03R             0.92   -0.89     0.35
DAILY AVG.       0.00              0.03   -0.03     0.01
DAYS >= .01         2               5.9    -3.9        8
DAYS >= .10         0               2.4    -2.4        1
DAYS >= .50         0               0.3    -0.3        0
DAYS >= 1.00        0               0.1    -0.1        0
GREATEST
 24 HR. TOTAL    0.03   03/01 TO 03/02           03/28 TO 03/28
                                                          03/28 TO 03/28
                                                          03/28 TO 03/28
 STORM TOTAL       MM                                 MM
 (MM/DD(HH))            MM                    03/28(00) TO 03/28(00)
                                                 03/28(00) TO 03/28(00)8
                                                 03/28(00) TO 03/28(00)8

SNOWFALL (INCHES)
RECORDS
 TOTAL             MM   5
TOTALS              T               11.7

DEGREE_DAYS
HEATING TOTAL     483               763    -280      666
 SINCE 7/1       4863              5202    -339     4817
COOLING TOTAL       0                 0       0        0
 SINCE 1/1          0                 0       0        0

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

WIND (MPH)
AVERAGE WIND SPEED              11.5
RESULTANT WIND SPEED/DIRECTION   5/203
HIGHEST WIND SPEED/DIRECTION    46/180    DATE  03/18
HIGHEST GUST SPEED/DIRECTION    58/190    DATE  03/18

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.50
NUMBER OF DAYS FAIR            9
NUMBER OF DAYS PC             20
NUMBER OF DAYS CLOUDY          2

AVERAGE RH (PERCENT)     34

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          1     HAIL                       0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                2     SLEET                      0
FOG                       2     FOG W/VIS <= 1/4 MILE      0
HAZE                      3

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

$$

Weather History

April 1 to April 7 – This Week in Denver Weather History

April 1, 2012 Thornton Weather Leave a comment

April in the Denver area can offer up an extraordinary array of weather conditions. As we discussed in our April weather preview, everything from wind and snow to thunderstorms and tornadoes can make an appearance. We see this variety in our look back at this week in Denver weather history which includes all of those conditions and more.

From the National Weather Service:

31-1

In 1876…heavy snow began during the night and lasted all day on the 31st and through the morning of the 1st. The average depth of snow fall was 10 to 12 inches…but strong winds whipped the snow into drifts of 8 to 10 feet deep on the streets of the city. Precipitation from the storm was 1.03 inches on the 31st and 0.37 inch on the 1st.

In 1891…heavy moist snowfall totaled 18.0 inches in the city. Northeast winds were sustained to 20 mph with gusts to 24 mph on the 31st.

In 1936…northeast winds sustained to 21 mph produced a light dust storm in the city.

In 1975…a major storm dumped 9.3 inches of snowfall at Stapleton International Airport where northwest winds gusted to 41 mph. Rain changed to snow on the afternoon of the 31st…reducing the visibility to as low as 1/8 mile. Snow continued all day on the 1st and accumulated to a depth of 8 inches on the ground. The minimum temperature of 10 degrees on the 1st set a new record low for the date.

31-2

In 1980…the second major blizzard in 5 days buried much of eastern Colorado under 6 to 12 inches of snow. Some drifts were up to 22 feet high. Hundreds of travelers were stranded. Over 3000 families were without power. Livestock losses were high. Metro Denver escaped the main brunt of this storm. At Stapleton International Airport…only 6.3 inches of snow fell over the 3-day period and north winds gusted to only 22 mph on the 1st.

31-3

In 1979…total snowfall of 6.6 inches was measured at Stapleton International Airport where north winds gusted to 31 mph on the 31st. The greatest accumulation of snow on the ground was 3 inches on the 1st.

31-4

In 1905…much rain and some snow occurred over the 5 days behind an apparent cold front. Precipitation totaled 2.00 inches. There was a thunderstorm on the 3rd. Snowfall totaled 3.0 inches on the 4th. North winds were sustained to 34 mph on the 1st and 2nd and to 30 mph on the 3rd. High temperatures during the period ranged from the upper 30’s to the lower 40’s. Low temperatures were in the upper 20’s and lower 30’s.

In 1987…a vigorous cold front produced 2.3 inches of snowfall at Stapleton International Airport where northeast winds gusted to 39 mph. The temperature dropped from a maximum of 59 degrees at mid-morning to a low of 25 degrees at midnight.

1-2

In 1963…strong winds buffeted metro Denver…while wind- whipped fires consumed grassland on the plains. A child was injured by a windblown falling tree in Castle Rock. Southwest winds gusted to 52 mph at Stapleton Airport… Causing some blowing dust. The worst fire storm burned over 25 thousand acres of grazing land in southern Weld County near Roggen northeast of Denver.

In 1984…a snowstorm with near-blizzard conditions over eastern Colorado closed many roads…including I-70 and I-76 east of Denver and I-25 between Denver and Colorado Springs. At Stapleton International Airport…snowfall totaled only 2.5 inches…but north winds gusted to 45 mph on the 2nd.

In 1999…moist upslope conditions allowed heavy snow to develop in the Front Range foothills where snowfall totals included: 10 inches at aspen park and Evergreen; 9 inches at turkey creek; 8 inches at Idaho Springs and Genesee; 7 inches at Aspen Springs…Crow Hill…Intercanyon…and Lake George.

In metro Denver snowfall totals included: 10 inches south of Sedalia; 8 inches in Littleton; 7 inches at Morrison; 6 inches at Highlands Ranch; and 4 to 5 inches in Northglenn…Parker and near Louisville. Snowfall totaled 4.7 inches at the site of the former Stapleton International Airport.

1-3

In 1945…snow fell across metro Denver for a total of 51 consecutive hours. While the storm was not accompanied by excessive snow…the long duration made the event a heavy snow producer. Snowfall totaled 10.7 inches in downtown Denver with 9.5 inches recorded at Stapleton Airport. North winds were sustained to 21 mph on the 1st; otherwise winds were not strong. The air mass was very cold for April. The high temperatures of 26 on the 2nd and 17 on the 3rd were record low maximums for the dates. The latter was also a record low maximum for the month. Warm weather following the storm quickly melted the snow.

In 1973…heavy snow fell at Stapleton International Airport where 8.7 inches were measured. Snow began late on the 1st and continued through early morning on the 3rd. Thunder accompanied the snow during the late morning and afternoon of the 2nd. North winds gusted to 33 mph on the 2nd and 37 mph on the 3rd. Snow only accumulated to a depth of 5 inches on the ground due to melting.

In 1977 a foot of snow fell in Boulder and Broomfield. The Denver-Boulder turnpike was closed for an hour after numerous minor traffic accidents. At Stapleton International Airport…snowfall totaled 4.7 inches and southeast winds gusted to 32 mph on the 2nd. The greatest depth of snow on the ground was only 3 inches due to melting.

Continue reading April 1 to April 7 – This Week in Denver Weather History →

Thornton Weather

Sunday brings another record day; March 2012 likely to go into record books

March 26, 2012 Thornton Weather Leave a comment

Another unseasonably mild day led to another high temperature record being tied on Sunday. As the unseasonably warm weather continues, March 2012 is almost certain to go into the record books on a number of marks.

The temperature at Denver International Airport reached 75 degrees at 4:05pm Sunday afternoon. This tied the record high temperature for the date last set in 1998. This is far and above the normal for the date of 57 degrees.

Here in Thornton we were a bit cooler and reached a high temperature of 72.3 degrees.

The record-tying mark is the fifth time so far this month that the record high temperature was tied or broken. Other days with record highs this month:

76 degrees on March 23, which tied the old record of 76 set in 1967
76 degrees on March 17, which broke the old record of 75 set in 1974
75 degrees on March 16, which broke the old record of 74 set just one year ago in 2011
74 degrees on March 13, which tied the old record of 74 set in 2007 and previous years

Officially Denver has recorded only a trace of snow this month and a scant 0.03 inch of precipitation. Given the forecast for the coming week, it is likely the month will end with those totals. If it does, March 2012 will go into the history books as the least snowiest and driest March on record.

In terms of temperatures, Denver’s overall average temperature for the month so far is at 47.0 degrees. That would put the month in a tie for the fourth warmest March on record. However with temperatures expected to remain unseasonably warm through the week, there is a good chance we will climb the ‘top 10’ list even further.

Click here for a list of the ‘top 10’ Marches.

Weather History

March 25 to March 31 – This Week in Denver Weather History

March 25, 2012 Thornton Weather Leave a comment

In stark contrast to the extremely dry and mild month we are experiencing now, March is normally known for its snow. In our look back at this week in Denver weather history we see many significant snow events that have occurred in the past and are much more representative of Denver’s March weather.

From the National Weather Service:

23-25

In 1891…rain changed to snow and totaled 8.8 inches in downtown Denver. Most of the snow fell on the 24th. Winds were light.

In 1964…heavy snowfall of 5.8 inches was measured at Stapleton International Airport. North-northeast winds gusted to 21 mph behind a cold front.

24-25

In 1904…west Bora winds sustained to 40 mph with gusts to 55 mph warmed the temperature to a high of 49 degrees on the 24th. Overnight…a cold front produced 4.5 inches of snow. The high temperature was only 34 degrees on the 25th.

In 1955…a vigorous cold front with winds sustained to 34 mph and gusts to 39 mph briefly reduced the visibility to 2 miles in blowing dust at Stapleton Airport. Post-frontal heavy snowfall totaled 9.5 inches at Stapleton Airport where the maximum snow depth on the ground was 7 inches.

24-26

In 1959…the second major spring storm in less than a week dumped 10 to 20 inches of wet snow across northeastern Colorado. Snowfall totaled 14.3 inches at Stapleton Airport where north winds gusted to 36 mph…causing near-blizzard conditions with visibilities frequently reduced to 1/2 mile in snow and blowing snow. Many travelers were marooned when trains…planes…and buses were unable to make their schedules. Utility lines were again damaged as a result of the storm.

In 1874…the wind blowing in gusts from the west-northwest filled the air with dust so dense that only the houses in the immediate neighborhood of the weather station could be recognized. The brisk winds continued through the afternoon.

In 1886…heavy snowfall of 6.5 inches occurred in the city.

In 1896…northwest winds sustained to 58 mph with gusts to 65 mph warmed the temperature to a high of 70 degrees.

In 1911…west winds were sustained to 43 mph. The Chinook winds warmed the temperature to a high of 65 degrees.

In 1925…northwest winds were sustained to 41 mph with gusts to 46 mph.

In 1950…strong Chinook winds gusted to 50 mph at Stapleton Airport.

In 1976…3.4 inches of snow fell at Stapleton International Airport where northeast winds gusted to 46 mph. The strong winds at 20 to 35 mph all day produced a rare “snirt” storm when blowing dust and dirt became mixed with snow and blowing snow reducing the visibility to as low as 1/4 mile at Stapleton International Airport.

In 1984…1 to 4 inches of new snow fell across metro Denver. Icy roads contributed to many accidents. The most hazardous conditions occurred in the foothills west of Denver. Both I-70 and U.S. 40 were closed at the height of the Sunday afternoon ski rush…causing delays of many hours. Snowfall totaled only 1.0 inch at Stapleton International Airport with only a trace on the ground due to melting.

In 1988…high winds in the mountains spread over metro Denver. A wind gust to 75 mph was noted in Boulder where a traffic light was downed. Power outages were reported in Boulder County. Northwest winds to 46 mph were recorded at Stapleton International Airport.

Continue reading March 25 to March 31 – This Week in Denver Weather History →

Weather History

March 18 to March 24 – This Week in Denver Weather History

March 18, 2012 Thornton Weather Leave a comment

As our snowiest month, heavy, wet snows are not at all unusual in March. Certainly we see many of those types of events in our look back at this week in Denver weather history. Also notable are the high wind events including one in 1995 that brought down two houses under construction in Thornton.

From the National Weather Service:

9-19

In 1906…an extended cold and blustery period occurred with light snow totaling 14.4 inches over 11 consecutive days. The greatest amount of snow on a single day was 4.0 inches on the 15th. Only a trace of snow fell on the 12th and 17th. High temperatures were below freezing for the entire period. The coldest were 14 degrees on the 16th and 18 degrees on the 17th. Both readings were record low maximums for the dates. Low temperatures were mostly in the single digits. The coldest were 2 degrees below zero on the 16th and 5 degrees below zero on the 19th. Northeast winds were sustained to 22 mph on the 9th. North winds were sustained to 36 mph on the 10th…32 mph on the 13th…and 22 mph on the 15th.

17-18

In 1923…4.2 inches of snow fell over downtown Denver. Northwest winds were sustained to 45 mph with gusts to 49 on the 17th. Low temperature of zero degrees on the 18th was the lowest of the month that year.

In 1944…heavy snow fell across metro Denver. The storm started as rain on the 17th…but soon turned to snow. Snowfall amounts totaled 8.5 inches in downtown Denver and 11.0 inches at Stapleton Airport. The highest wind recorded during the storm was 23 mph on the 17th.

In 1961…a major winter storm dumped 10.7 inches of snow at Stapleton Airport. Most of the snow…9.7 inches…fell on the 18th. Winds were light.

In 1994…strong winds buffeted metro Denver. West winds gusted to 51 mph at Stapleton International Airport on the 17th. Other significant wind gusts included 85 mph atop squaw mountain south of Idaho Springs…and 82 mph at Rollinsville southwest of Boulder…both on the 18th.

In 1996…a second storm in less than 3 days dumped heavy snow in the mountains and foothills again…but snowfall amounts across metro Denver ranged from only 2 to 4 inches. The heavy snowfall resulted in several traffic accidents along I-25 and I-70…south and west of Denver respectively. The major accidents involved at least 30 cars and resulted in several minor injuries. The accidents closed both highways for a time. Snowfall totals included 13 inches at Evergreen and 10 inches at conifer. Snowfall totaled only 0.7 inch at the site of the former Stapleton International Airport. At Denver International Airport… North winds gusted to 28 mph on the 17th and 39 mph on the 18th.

17-19

In 1933…rain changed to snow on the evening of the 17th and continued through mid-day of the 19th. Snowfall totaled 5.6 inches with 0.83 inch of precipitation in in the city. North winds were sustained to 38 mph with gusts to 46 mph on the 18th and to 30 mph with gusts to 43 mph on the 19th.

In 2003…one of the worst blizzards since historic records began in 1872 struck metro Denver with a vengeance. Heavy wet snow accumulating to around 3 feet in the city and to more than 7 feet in the foothills brought transportation to a near standstill. North winds sustained to 30 mph with gusts as high as 41 mph produced drifts to 6 feet in the city. The estimated cost of property damage alone…not including large commercial buildings…was 93 million dollars… Making it the costliest snowstorm ever. Mayor Wellington Webb of Denver said…”this is the storm of the century…a backbreaker…a record breaker…a roof breaker.” two people died in Aurora from heart attacks after shoveling the heavy wet snow. The national guard sent 40 soldiers and 20 heavy duty vehicles to rescue stranded travelers along I-70 east of gun club road. The heavy wet snow caused roofs of homes and businesses to collapse. The snow also downed trees…branches…and power lines. Two people were injured when the roofs of their homes collapsed. In Denver alone…at least 258 structures were damaged. In Arvada…a roof collapse at west gate stables killed a horse. Up to 135 thousand people lost power during the storm…and it took several days for power to be restored in some areas. Denver International Airport was closed…stranding about 4000 travelers. The weight of the heavy snow caused a 40-foot gash in a portion of the tent roof…forcing the evacuation of that section of the main terminal building. Avalanches in the mountains and foothills closed many roads…including I-70…stranding hundreds of skiers and travelers. Along I-70…an avalanche released by the Colorado Department of Transportation…blocked the interstate in both directions for several hours. Several residences between Bakerville and Silver Plume were evacuated because of the high avalanche danger. At Eldora Ski Area…270 skiers were stranded when an avalanche closed the main access road. After the storm ended…a military helicopter had to ferry food to the resort until the road could be cleared. The heavy snow trapped thousands of residents in their foothills homes in Jefferson County for several days. Two homes burned to the ground when fire crews could not reach the residences. Some schools remained closed well into the following week. The storm officially dumped 31.8 inches of snow at the site of the former Stapleton International Airport…the most snowfall from a single storm since the all-time record snowfall of 37.5 inches on December 4-5…1913. The storm made March 2003 the snowiest March on record…the 4th snowiest month on record… And the 5th wettest March on record. The 22.9 inches of snow on the 18th into the 19th was the greatest 24 hour snowfall ever recorded in the city during the month of March. The storm was also a drought-buster…breaking 19 consecutive months of below normal precipitation in the city. Snowfall across metro Denver ranged from 2 feet to more than 3 feet. The highest amounts included: 40 inches in Aurora…38 inches in centennial and 6 miles east of Parker…37 inches at Buckley AFB…35 inches in southwest Denver…34 inches in Louisville… 32 inches in Arvada…31 inches in Broomfield and Westminster… And 22.5 inches in Boulder. In the foothills…snowfall ranged from 3 feet to more than 7 feet. Some of the most impressive storm totals included: 87.5 inches atop Fritz Peak and in Rollinsville…83 inches at Cabin Creek…74 inches near Bergen Park…73 inches northwest of Evergreen…72 inches in Coal Creek Canyon…70 inches at Georgetown…63 inches near Jamestown…60 inches near Blackhawk…55 inches at Eldora Ski Area…54 inches 8 miles west of Sedalia…and 46.6 inches at Ken Caryl Ranch. The storm was the result of a very moist…intense slow moving pacific system which tracked across the four corners and into southeastern Colorado…which allowed deep easterly upslope flow to form along the Front Range.

In 1883…0.3 inch of snow fell in downtown Denver. This was the only measurable snowfall of the month.

In 1903…rain changed to sleet and then to snow…which became heavy. Post-frontal snowfall totaled 7.0 inches over the city. North winds were sustained to 51 mph with gusts as high as 60 mph.

In 1905…northwest winds were sustained to 42 mph.

In 1914…northeast winds were sustained to 46 mph with gusts to 56 mph behind a strong cold front. Snowfall was 3.4 inches over the city…but most of the snow melted as it fell. The estimated amount of melted snow was 8.1 inches.

In 1920…a terrific windstorm occurred along the eastern foothills. Two deaths were attributed to the storm and some damage occurred. Both Denver and Boulder were affected by the strong winds. West winds were sustained to 51 mph with gusts as high as 66 mph in downtown Denver. The strong winds did considerable damage to property… Wires…plate glass windows…and indirectly loss by fire. The wind caused the death of one young girl by toppling the side of a brick building on her as she was standing on a corner waiting for a car. The wind was also responsible for several severe auto accidents due to blowing debris into the streets and blowing dust and dirt into the eyes of drivers.

In 1954…west winds at sustained speeds of 40 mph and gusts as high as 56 mph produced some blowing dust at Stapleton Airport.

In 1979…heavy snow totaled 4 to 12 inches along the Front Range from Denver north. I-25 was closed for a brief time between Denver and Cheyenne. New snowfall totaled 4.3 inches at Stapleton International Airport where north winds gusted to 29 mph.

In 1998…a major winter storm dumped heavy snow over areas west from I-25 to the continental divide as strong upslope conditions developed. Two to 3 1/2 feet of snow fell in the foothills with 1 to 2 feet reported in west metro Denver. Snowfall totals included: 38 inches at Silver Spruce Ranch…2 miles south of Ward; 35 inches at Aspen Springs; 33 inches near Blackhawk; 30 inches at Eldora; 29 inches in Coal Creek Canyon; 27 inches at Conifer… Chief Hosa…and Nederland; 25 inches at Rollinsville and Gross Reservoir; 21 inches at Evergreen; and 15 to 19 inches at Broomfield…Lakewood…and Table Mesa in Boulder. Elsewhere across metro Denver…snowfall ranged from 8 to 14 inches. Snowfall totaled only 7.9 inches at the site of the former Stapleton International Airport. East winds gusted to 31 mph at Denver International Airport.

Continue reading March 18 to March 24 – This Week in Denver Weather History →

Weather History

March 11 to March 17 – This Week in Denver Weather History

March 11, 2012 Thornton Weather Leave a comment

March is usually a month of transition in Denver as winter winds down and spring begins to assert itself. This leads to many different types of weather events from high winds, to monstrous snowstorms and even tornadoes. Our look back at this week in Denver weather history shows that all of these can occur during this time of the year.

From the National Weather Service:

9-11

In 1927…rain changed to heavy snow behind a cold front and totaled 7.7 inches over downtown Denver. North winds were sustained to 37 mph with an extreme velocity to 38 mph on the 11th.

In 1955…a strong windstorm raked the eastern foothills. A wind gust to 95 mph was recorded at Rocky Flats with a gust to 60 mph measured at Valmont. Damage in Boulder totaled 10 thousand dollars. Minor injuries also occurred. The strong winds were associated with a vigorous cold front that produced northwest winds at 40 mph with gusts as high as 52 mph at Stapleton Airport where the visibility was briefly reduced to 3/4 mile in blowing dust on the 10th.

In 1968…5.5 inches of snow fell at Stapleton International Airport where northeast winds gusted to 24 mph on the 10th.

9-19

10-11

In 1886…snowfall of 3.5 inches was measured in downtown Denver. Apparent post-frontal north winds were sustained to 43 mph on the 11th.

In 1977…a major blizzard struck metro Denver. Snowfall totaled 8.0 inches at Stapleton International Airport where north winds at speeds of 30 to 40 mph with gusts to 60 mph frequently reduced visibilities in blowing snow to 1/4 mile or less. Most of the snow…7.7 inches…fell on the 10th. The snow ended by daybreak on the 11th…but strong north winds persisted through the day.

In 1988…a late winter storm produced heavy snow and wind… Mainly north of Denver. Wind gusts reached 62 mph at Keenesburg and produced a lot of blowing snow…closing schools in southwest weld County. The storm closed I-70 east of Denver. Only 1.1 inch of snow fell at Stapleton International Airport…but north winds gusted to 39 mph.

10-12

In 1924…snowfall was heavy and totaled 9.9 inches over downtown Denver. North winds were sustained to 18 mph on the 11th.

In 2001…heavy snow fell over northeast Colorado and metro Denver when a combination of upslope winds and convective snow bands formed over the area. Storm totals included: 11 inches at the Eldora Ski Resort; 10 inches at Genesee; 8 inches at Elizabeth…atop Lookout Mountain…near Sedalia… And at Strasburg; 7 inches near Castle Rock and Evergreen; and 6 inches in Aurora…atop Crow Hill…and in Parker. Elsewhere across metro Denver…snowfall ranged from 2 to 5 inches with 3.9 inches at the site of the former Stapleton International Airport. North winds gusted to 28 mph at Denver International Airport on the 10th.

Continue reading March 11 to March 17 – This Week in Denver Weather History →

Weather History

March 4 to March 10 – This Week in Denver Weather History

March 4, 2012 Thornton Weather Leave a comment

March is the Mile High City’s snowiest month as moisture-laden storms can oftentimes bring our heaviest snows. In our look back at this week in Denver weather history we see many occasions where monstrous snowstorms buried the city.

From the National Weather Service:

2-4

In 1963…heavy wet snow was accompanied by strong gusty winds across metro Denver. Snowfall totaled 11.6 inches at Stapleton Airport where north winds gusting to 44 mph caused much blowing and drifting snow. Hazardous driving conditions resulted in many traffic accidents.

In 1976…snowfall totaled 8.0 inches at Stapleton International Airport where…on the 4th…northeast winds gusted to 31 mph reducing the visibility to as low as 1/4 mile. Maximum snow depth on the ground was 7 inches. Nine inches of snow were measured in Boulder.

3-4

In 1932…a dust storm occurred on the 3rd during the late afternoon. North winds gusting as high as 38 mph behind a cold front kicked up much blowing dust. Light snow developed during the evening and continued through the early morning of the 4th. Snowfall totaled 2.7 inches.

In 1934…strong winds raked Boulder. A wind gust to 62 mph was recorded at Valmont just east of Boulder. The strong winds caused hundreds of dollars of damage in Boulder.

In 1981…the most vigorous snow storm of the season struck the state…closing many schools and most highways connecting Denver…Colorado Springs…and Limon. North winds gusting to 43 mph whipped nearly 10 inches of snow in Denver into 3-foot drifts and snarled traffic on the morning of the 4th. Snowfall totaled 9.8 inches at Stapleton International Airport.

In 1989…a storm dumped 2 to 6 inches of snow across metro Denver. The snow caused 2-hour air traffic delays at Stapleton International Airport where 3.0 inches of snow fell and north winds gusted to 23 mph on the 3rd. There were many traffic accidents across metro Denver. I-70 was closed east of Denver for a time on the 3rd.

In 1991…high winds raked the eastern foothills. Wind gusts of 60 to 90 mph were common with 119 mph recorded at Wondervu southwest of Boulder…106 mph on Shanahan Ridge and 92 mph at Table Mesa…both in southwest Boulder. Several trees were uprooted and traffic signs and lights blown over. Flying debris caused damage to homes… Buildings…and cars.

In Boulder…a stop sign was blown onto a car. There were no reports of injuries. Southwest winds gusting as high as 48 mph briefly reduced the prevailing visibility to as low as 1/16th mile in blowing dust at Stapleton International Airport on the 4th.

3-5

In 1961…snowfall totaled 8.3 inches at Stapleton Airport over the 3-day period with most of the snow…4.4 inches…falling on the 3rd. Winds were generally light gusting to only 23 mph.

In 1887…snowfall was only 0.1 inch. This was the earliest last measurable snow of the season.

In 1971…a wind gust to 102 mph was recorded at the National Center for Atmospheric Research in Boulder. A wind gust to 83 mph was measured at the National Bureau of Standards. In downtown Boulder…sustained winds reached 35 mph with gusts as high as 57 mph. No significant damage was reported. West winds gusted to only 28 mph at Stapleton International Airport.

In 1982…brief heavy snow accompanied by a few thunderstorms struck metro Denver. Lightning struck a house in Arvada setting it afire. The thunderstorm produced 5 inches of snowfall in a 2-hour period in Wheat Ridge. The snow made roads very icy and slick causing a 59-car pile-up on I-70 in north Denver. Snowfall with thunder totaled only 1.3 inches at Stapleton International Airport.

In 1997…a fast moving pacific storm produced heavy snow in the foothills. Snowfall at conifer measured 9 inches. Only light snow fell elsewhere over metro Denver. Snowfall totaled only 1.2 inches at the site of the former Stapleton International Airport. North northeast winds gusted to 28 mph at Denver International Airport.

Continue reading March 4 to March 10 – This Week in Denver Weather History →

Weather History

February 26 to March 3 – This Week in Denver Weather History

February 26, 2012 Thornton Weather 1 Comment

In the past week Denver has seen its fair share of wind and snow and looking back at this week in Denver weather history, we see both are common conditions.

From the National Weather Service:

22-29

In 1960…heavy snowfall of 6.1 inches at Stapleton Airport on the 22nd and 23rd marked the beginning of a protracted cold spell which lasted until the end of the month. The cloudy… Cold weather was accompanied by occasional light snow or flurries and fog. New record low temperatures for the dates were set on the 24th thru the 29th with the lowest temperature of 11 degrees below zero on the 28th. The seven consecutive days of low temperatures of zero or below had been exceeded in duration only 4 times previously. New low maximum temperatures for the dates were set on the 23rd… 24th…and the 26th thru the 29th with the lowest maximum temperature of 8 degrees recorded on the 26th.

25-26

In 1971…a wind gust to 100 mph was recorded in Boulder at the National Center for Atmospheric Research. The cold west winds gusted to 53 mph in downtown Boulder. No damage was reported. Northwest winds gusted to 31 mph on the 25th and to 38 mph on the 26th at Stapleton International Airport.

In 1984…a heavy snow storm left 1 to 2 feet of new snow in the foothills west of Denver. I-70 was closed…stranding skiers returning from the mountains. Most had to spend several hours in Idaho Springs. The snow spread over metro Denver with 9 inches at Littleton…Castle Rock…and Boulder and up to 5 inches in Aurora and Denver. Snowfall totaled only 3.6 inches at Stapleton International Airport where north winds gusted to 31 mph.

In 1884…heavy snowfall totaled 6.0 inches in downtown Denver.

In 1908…a duststorm occurred in the city during the afternoon. Northwest winds were sustained from 14 to 24 mph.

In 1918…pre-frontal Chinook winds from the southwest… Sustained to 43 mph with a maximum velocity to 52 mph… Warmed temperatures to a high of 62 degrees.

In 1954…strong Chinook winds gusting to 52 mph during the morning warmed the temperature in Denver to a balmy 65 degrees by early afternoon. A vigorous Canadian cold front during the late afternoon produced north winds at sustained speeds of 52 mph with gusts as high as 65 mph and billows of blowing dust…which reduced the visibility to as low as 1 mile at Stapleton Airport. Showers left half an inch of snow on the ground as the temperature dipped to a low of 27 degrees before midnight.

In 1989…a brief rain shower produced a microburst wind gust to 51 mph at Stapleton International Airport.

In 1997…snowfall totaled 4 to 6 inches in and near the foothills. Only 0.8 inch of snow fell at the site of the former Stapleton International Airport. Northeast winds gusted to 29 mph at Denver International Airport.

26-27

In 1893…heavy snowfall totaled 7.9 inches in downtown Denver. Most of the snow…6.7 inches…fell on the 27th. Northeast winds were sustained to 18 mph with gusts to 30 mph behind an apparent cold front.

In 1939…heavy snowfall of 8.1 inches was the heaviest of the month in downtown Denver. North winds sustained to 21 mph on the 26th and to 28 mph on the 27th caused much drifting. The greatest snow depth on the ground was 7.8 inches at noon on the 27th.

In 1987…a snowstorm dropped 4 to 8 inches of snow across metro Denver…causing flight delays at Stapleton International Airport where snowfall totaled 3.8 inches and north winds gusted to 24 mph. Both I-70 and I-25 were closed for a time to the east and south of Denver.

Continue reading February 26 to March 3 – This Week in Denver Weather History →

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