Weather in Colorado is always interesting but springtime can bring the entire gamut of conditions. Looking back at this week in Denver weather history we see just how varied this time of year – from flooding rains to heavy snowfall to severe thunderstorms it can and has all happened.

From the National Weather Service:

23-24

In 1883…snowfall totaled 7.6 inches in downtown Denver.

In 1904…a thunderstorm produced hail during the late evening of the 23rd. Apparent post-frontal rain changed to snow during the early morning of the 24th…but totaled only 2.0 inches. Precipitation consisting of rain…melted hail…and snow totaled 0.60 inch. Northeast winds were sustained to 41 mph with gusts as high as 52 mph on the 24th.

In 1905…rain changed to snow and totaled 8.0 inches. Much of the snow melted as it fell with only 2.5 inches measured on the ground. Precipitation totaled 1.88 inches. Northeast winds were sustained to 20 mph on the 23rd.

In 1942…the South Platte River reached flood conditions in the city. As many as 15 thousand residents were warned to evacuate their homes temporarily. Two lives were lost in the city. Four bridges were washed out by the flood waters and other bridges were endangered. The damage was generally limited to bridges that were in poor condition. However…the flood waters did not overflow their channel banks within the city limits.

In 1980…heavy rain began in the eastern foothills on the night of the 23rd and turned to heavy wet snow on the 24th. Up to a foot and a half of snow fell in the foothills west of Denver. At Stapleton International Airport precipitation totaled 1.58 inches…but only 3.7 inches of snow fell from the storm. East winds gusted to 24 mph.

In 1997…locations in and near the foothills received the greatest snow of the year as a winter-like storm system moved into metro Denver. East to southeast winds at speeds of 15 to 35 mph were common with even stronger gusts above 9 thousand feet. Snow fell at a rate of 2 to 3 inches an hour as deep upslope combined with a moist and unstable air mass. The snow began in the foothills above 7500 feet during the evening of the 23rd. By sunrise the snow level had dropped to 5000 feet. The hardest hit areas extended from I-25 into the foothills. Snowfall totals in the foothills ranged from 1 1/2 to over 3 1/2 feet. In the city…snowfall ranged from 8 to 18 inches. Some snowfall amounts included: 36 inches at Coal Creek Canyon; 31 inches at Nederland and Wondervu; 20 to 24 inches near Blackhawk… At Echo Lake…and North Turkey Creek Canyon; 15 to 19 inches at Boulder…central city…conifer…Evergreen…Georgetown… And Louisville; 8 to 14 inches in Arvada…Broomfield… Westminster…Wheat Ridge…Castle Rock…and Ken Caryl Ranch. Only 2.3 inches of snow fell at the site of the former Stapleton International Airport on the 24th. East winds gusted to 36 mph at Denver International Airport on the 24th.

In 2003…a strong and deep northerly flow circulating around a closed upper low pressure center allowed heavy snow to fall in the mountains and eastern foothills. Snowfall totaled 14 inches in Idaho Springs. Rain was mixed with snow and thunder across metro Denver. Snowfall was only 0.9 inch overnight at the site of the former Stapleton International Airport. Precipitation totaled 1.34 inches at Denver International Airport…where northwest winds gusted to 55 mph on the 23rd.

In 2007…a storm system intensified over southeast Colorado… Allowing for heavy snow and rain to develop over much of north-central and northeast Colorado. Severe thunderstorms preceded the storm system on the 23rd…affecting the urban corridor. Nickel size hail was reported in Boulder and a small landspout touched down near Byers. On the 24th…heavy snow fell in the foothills west of Denver and Boulder…where storm totals ranged from 1 to 2 feet. Heavy snow also occurred along the palmer divide…with storm totals of 10 to 16 inches. Elsewhere…a steady moderate to heavy rainfall was reported. Denver International Airport measured 2.09 inches of rainfall…which shattered the previous 24-hr record of 1.29 inches for the 24th of April. The heavy wet snow caused several power outages. In some instances it took several days to restore power. Several road closures were reported…including interstates 25 and 70. A jackknifed semi-trailer backed up traffic for nearly 20 miles…on southbound I-25…between Denver and Colorado springs. In addition…a 50-ton Boulder blocked the southbound lane of State Highway 285…near Parmalee Gulch. Crews had to use explosives to break up the Boulder and clear the debris. Stranded buses and impassable roadways also forced several school closures.

Continue reading April 24 to April 30 – This Week in Denver Weather History →

As we enter the latter half of April the weather history calendar starts to reflect shift in the type of weather events we see. There are still plenty of significant snowfall events. However spring severe weather starts to appear with greater frequency including heavy rain, hail and even tornadoes.

From the National Weather Service:

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In 2001…a huge dust storm over southern and Inner Mongolia during April 3rd through the 6th lifted desert dust into the jet stream. This dust cloud moved over metro Denver on the 13th and persisted through the 17th. The cloud created widespread haze…giving the sky a milkish cast due to the scattering of incoming solar radiation.

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In 1922…heavy snowfall totaled 9.0 inches in downtown Denver. Most of the snow…6.0 inches…fell on the 16th. This was the third major snow storm in a week. Northwest winds were sustained to 43 mph with gusts to 47 mph on the 15th.

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In 1944…heavy snowfall totaled 7.5 inches in downtown Denver. Northwest winds were sustained to 18 mph on the 16th.

16-18

In 2009…a potent spring storm brought heavy snow to locations in and near the Front Range foothills. A deep easterly upslope produced nearly 5 feet of snow in parts of the foothills. The heavy snow resulted in the closure of Interstate 70…from Golden west to Vail…for approximately 16 hours. The heavy snow snapped power lines in Evergreen and Nederland. The ensuing outages affected 14200 residents. In the Front Range foothills…storm totals included: 56 inches…3 miles south of Rollinsville; 54 inches…3 miles southeast of Pinecliffe…43 inches at Aspen Springs…42 inches at Evergreen…38 inches near conifer; 37 inches at St. Mary’s glacier…and 34 inches near Nederland. Along the urban corridor and Palmer Divide…the heaviest snow occurred above 5500 feet on the 17th. Storm totals included: 22 inches…8.5 miles southwest of Franktown; 18 inches…10 miles south-southeast of Buckley Air Force Base; 17 inches near Cherry Creek and 7 miles south of Sedalia… 16 inches…6.5 miles southwest of Castle Rock; 15 inches near Beverly Hills; 12 inches near Highlands Ranch and Lafayette…with 11 inches in Broomfield. Elsewhere storm totals ranged from 4 to 10 inches. Officially…only 2.6 inches of snow was observed at Denver International Airport. The 24-hr precipitation for the day however was 1.16 inches… Which established a new record for April 17th.

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In 1889…northwest winds were sustained to 48 mph.

In 1899…apparent post-frontal north winds were sustained to 42 mph with gusts as high as 48 mph.

In 1935…light dust moved over the city behind an apparent dry cold front…which produced northeast winds to 19 mph with gusts to 20 mph.

In 1978…winds estimated to 70 mph occurred in Morrison. Northwest winds gusted to 49 mph at Stapleton International Airport.

In 2000…strong pre-frontal winds and widely scattered thunderstorms caused high winds to develop across northern metro Denver and portions of the northeast plains. Peak wind gusts included 75 mph at Louisville. South winds gusted to only 28 mph at Denver International Airport.

In 2002…strong southwest winds in advance of a cold front gusted to 52 mph at Denver International Airport.

In 2003…severe thunderstorms produced 1 inch diameter hail 7 miles east of Brighton. Strong thunderstorm winds blew out an auto windshield near Denver International Airport where south winds gusted to 48 mph.

Continue reading April 17 to April 23 – This Week in Denver Weather History →

April can be a very eventful weather month and we see that in our look back at this week in Denver weather history. Particularly notable are many major snow events including two in recent history – one in 2001 and another in 2005.

From the National Weather Service:

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.

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.

9-10

In 1900…rain changed to heavy snow and totaled 6.8 inches in downtown Denver overnight. A thunderstorm occurred on the 9th. North winds were sustained to 32 mph with gusts to 38 mph on the 10th. Precipitation totaled 1.39 inches.

In 1933…post-frontal heavy snowfall totaled 9.4 inches in downtown Denver. East winds were sustained to 21 mph with gusts to 22 mph on the 9th.

In 1944…7.0 inches of snow fell on downtown Denver. Northeast winds were sustained to 24 mph on the 9th.

In 1977…the two warmest days of the month resulted in two temperature records being set. High temperature of 81 degrees on the 9th set a new record maximum for the date. High temperature of 80 degrees on the 10th equaled the record maximum for the date. The unusually warm weather for so early in April produced a late afternoon thunderstorm on the 10th.

In 1993…strong downslope winds occurred along the Front Range. While the strongest winds were in the foothills north of Denver…wind gusts to 69 mph were recorded at Jefferson County Airport in Broomfield. Northwest winds gusted to 39 mph at Stapleton International Airport.

In 2004…a spring storm brought heavy snow to metro Denver. The heaviest snow fell in the foothills and over and near higher terrain. Snowfall totals included: 20 inches near Jamestown; 18 inches atop gold hill; 17 inches near Evergreen; 15 inches at Nederland and Eldora; 13 inches at Blackhawk; 11 inches at Aspen Springs; 9 inches in Louisville; 8 inches at Ken Caryl; 6 inches at Niwot… Near Sedalia…and in Thornton; 5 inches in Lakewood… Lyons…and Westminster. Snowfall was 4.4 inches at Denver Stapleton. Northwest winds gusted to 21 mph at Denver International Airport.

In 2008…a very moist storm brought heavy snow to parts of the Front Range foothills. Storm totals included: 12.5 inches at Aspen Springs…11 inches…4 miles west- southwest of conifer; with 10.5 inches…3 miles north of central city and 6 miles southwest of Evergreen. Lesser amounts of 5 to 9 inches were observed elsewhere. North winds gusted to 43 mph at Denver International Airport on the 10th…and 1.8 inches of snow fell at the former Stapleton International Airport.

Continue reading April 10 to April 16 – This Week in Denver Weather History →

As we pointed out in our April weather preview, the month can bring just about any type of weather condition and we see that in our look back at this week in Denver weather history. From powerful, damaging winds to Arctic cold to heavy snowfall this has been an eventful week in the past.

From the National Weather Service:

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.

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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.

2-3

In 1955…strong west to southwest winds raked metro Denver on both days. Sustained winds as high as 37 mph with gusts to 60 mph were recorded at Stapleton Airport where the visibility was reduced to 1/4 mile in blowing dust.

In 1974…a heavy snowfall of 6.7 inches was accompanied by northeast wind gusts to 33 mph which produced some blowing snow across metro Denver. Over eastern Colorado many highways and schools were closed due to near-blizzard conditions from the storm.

In 1986…the worst snow storm of the season blasted metro Denver. Heavy snow and high winds combined to close roads… Schools…and airports. Portions of all interstate Highways out of Denver were closed at times. The snow came after an exceptionally mild late winter and early spring; trees and bushes had already bloomed and leafed out. The snow and wind snapped many of these…causing power outages. Total snowfall amounts in metro Denver ranged from 1 to 2 feet with 2 to 3 feet in the foothills. Snowfall totaled 12.6 inches at Stapleton International Airport where north winds gusting to 39 mph reduced the visibility to 1/8 mile in snow and blowing snow. Most of the snow fell on the 3rd when temperatures hovered around 30 degrees for most of the day. The heavy snow halted traffic and closed businesses. A 59- year-old man was found dead from exposure in northwest Denver. The roof of a toy store in Northglenn collapsed. A 100 thousand square foot section of a greenhouse roof collapsed in Golden…destroying over a million dollars worth of plants.

In 2000…a combination of strong instability and moist upslope winds allowed for a heavy…wet spring snowstorm to develop in and near the Front Range foothills. The heaviest snow occurred in southern Jefferson County. Storm totals included: 14 inches near conifer…12 inches near Evergreen and on Floyd hill; 11 inches near Blackhawk…Morrison…and tiny town; 10 inches at Aspen Springs and Eldora Ski Area; 9 inches at Chief Hosa; and 8 inches at both Golden Gate Canyon and Rollinsville. Only 2.1 inches of snow fell at the site of the former Stapleton International Airport. North winds gusted to 36 mph at Denver International Airport on the 2nd.

Continue reading April 3 to April 9 – This Week in Denver Weather History →