Temperatures continue to cool as we get further into fall and our look back at this week in Denver weather history provides some insight into the types of extreme weather that are possible this time of year. Noteworthy events include many incidences of damaging wind and some monstrous snowstorms.
From the National Weather Service:
In 2003…an extended warm spell resulted in 5 new temperature records. The high temperature of 84 degrees on the 18th equaled the record high for the date. High temperatures of 86 degrees on the 19th…83 degrees on the 21st…and 84 degrees on the 22nd were record highs for the dates. Low temperature of 49 degrees on the 23rd was a record high minimum for the date. Low temperatures during the period were in the 40’s and lower 50’s.
In 1990…an early winter storm dumped heavy snow across metro Denver. Snowfall amounts ranged from 4 to 8 inches in the foothills above 6500 feet elevation…4 to 7 inches in the Castle Rock area…and 2 to 5 inches across most of metro Denver and Boulder. Snowfall totaled 3.6 inches at Stapleton International Airport where northwest winds gusting to 48 mph kicked up some blowing dust shortly after a cold frontal passage on the 19th. However… Temperatures were warm enough to keep most roadways wet and slushy at lower elevations.
In 1906…heavy snowfall totaled 22.7 inches in the city over the 5 days. Rain changed to snow on the evening of the 19th…and snow continued through the late afternoon of the 23rd. The heaviest amount of snowfall…16.0 inches…fell from 8:00 pm on the 20th to 8:00 pm on the 22nd. The most snow on the ground was 13.3 inches on the evening of the 23rd. This was the first snow of the season and the only snow of the month. Winds during the storm were from the north at sustained speeds of 20 to 30 mph each day. Temperatures during the storm were generally in the 20’s.
In 1878…between 3:00 pm and 4:00 pm wind speeds averaged 48 mph with a maximum 1 minute sustained velocity to 96 mph at both 3:27 pm and 3:48 pm in downtown Denver. This is the highest sustained wind speed ever recorded in the city.
In 1986…a rare late October thunderstorm produced 3/4 inch diameter hail at Centennial Airport. Hail piled up 2 1/2 inches deep…causing some street flooding in south metro Denver.
In 2007…a storm system brought heavy snow to the southern Denver suburbs as well as the Palmer Divide south of Denver. Storm totals included: 7.5 inches near Castle Rock…Lone Tree and Greenwood Village…with 6.5 inches at Elizabeth. Snow drifts up to 2 feet deep were observed 6 miles south-southwest of Elizabeth. In the Denver Stapleton area…2.0 inches of snow was observed.
In 2009…heavy snow developed along the Palmer Divide south and southeast of Denver as a storm system tracked across southern Colorado and northern New Mexico. Storm totals included: 15 inches…15 miles north of Elizabeth…9 inches…5 miles south-southwest of Arapahoe Park; 8 inches in Highlands Ranch…5 miles south- southeast of Sedalia; 6.5 inches…8 miles southwest of Bennett and 6 inches in Parker. At Denver international… Only 1.5 inches of snowfall was observed.
In 1936…5.5 inches of snow fell over downtown Denver. Most of the snow…4.5 inches…fell on the 20th.
In 1920…the rare event of snow from a thunderstorm occurred in the city during the evening. Brilliant flashes of lightning and loud peals of thunder were first noted at 7:35 pm. Light rain began falling at 8:30 pm…and light moist snow began falling a few minutes later. Some soft hail was also seen falling with the rain and snow…but both melted almost as fast as they fell. The hail only continued for a few minutes…and the rain and snow ceased about 9:40 pm. The snowfall was the first to occur in Denver this season. The amount of precipitation at the station measured only 0.01 inch…but heavier amounts were reported from other parts of the city. Snowfall was only a trace.
In 1978…heavy rain on the 21st changed to snow by daybreak on the 22nd and continued the rest of the day. This was the first measurable snowfall of the season…but totaled only 1.7 inches at Stapleton International Airport where east winds gusted to 29 mph. While only a trace of snow covered the ground…precipitation totaled 1.27 inches.
In 1878…winds were sustained to 42 mph.
In 1887…the first measurable snow of the season occurred… Ending the longest snow-free period in Denver…232 days… Since the last snow on March 5th.
In 1947…the first snow of the season totaled only 1.6 inches. Post-frontal north winds caused temperatures to plunge from a high of 60 degrees at midnight to a low of only 30 degrees 24 hours later. This was the only snow of the month.
In 1985…high winds gusting from 60 to 80 mph buffeted the Front Range foothills. The strongest reported wind gust was 89 mph in eastern Boulder. A treehouse east of Boulder was set on fire by a downed power line. Two people in Boulder were injured. A woman broke her arm when the strong winds knocked her to the ground. A carpenter in the city suffered a severely cut hand while he was trying to repair a roof that was being torn from a building. At Stapleton International Airport…northwest winds gusted to 41 mph.
In 2001…west-northwest winds gusting as high as 54 mph warmed the temperature to a high of 70 degrees at Denver International Airport.
In 1914…post-frontal rain changed to snow. Precipitation totaled 2.72 inches…most of which was in the form of moist snow which melted as it fell in the business section of the city. About 3 inches of snow was measured on lawns in the residential areas on the morning of the 24th. Official snowfall totaled only 0.4 inch downtown… But an estimated 8.0 inches of snow melted as it fell. North to northeast winds were sustained to 29 mph with gusts to 30 mph on both days.
In 1975…a vigorous cold front moving across metro Denver followed by strong northeast winds gusting to 52 mph produced billows of blowing dust and plunged the temperature 21 degrees in an hour. The surface visibility was reduced to 1/4 mile in blowing dust at Stapleton International Airport. The temperature cooled from a daily record high of 81 degrees to a low of 38 degrees by day’s end. The first snowfall of the season totaled 2.7 inches on the 23rd. This was the only measurable snow of the month at Stapleton International Airport.
In 1995…heavy snow fell on the Palmer Ridge south of Denver and in the foothills west of Denver where snow amounts ranged from 4 to 8 inches. Sedalia…south of Denver… Received 8 inches of snow. Winds strengthened on the plains and produced blizzard conditions…reducing surface visibilities to less than 1/4 mile. I-70 was closed from just east of Denver at Gun Club Road to the Kansas border. Ten inches of snow fell at Strasburg east of Denver where north winds at sustained speeds of 35 to 45 mph with gusts as high as 60 mph produced 2 to 4 foot drifts. Snowfall totaled only 2.2 inches at the site of the former Stapleton International Airport. North winds gusted to 51 mph at Denver International Airport.
In 1876…skies were fair…but winds were sustained to 48 mph.
In 1942…a major storm dumped 10.2 inches of snow over downtown Denver. Post-frontal northeast winds were sustained to only 13 mph.
In 1955…the first snowfall of the season and the only measurable snow of the month dumped 4.1 inches of snow on Stapleton Airport. This was the single heaviest October snowfall in 13 years since 1942. The storm also brought the first sub-freezing temperatures of the season when the temperature dipped to a low of 25 degrees.
In 1956…southwest winds gusted to 53 mph and produced some blowing dust at Stapleton Airport.
In 1967…a northwest wind gust to 51 mph was recorded at Stapleton International Airport. In downtown Boulder… Winds were sustained at 20 mph with gusts in excess of 40 mph.
In 1981…strong winds occurred in the foothills. Wind gusts to 70 mph were reported at Wondervu.
In 1887…the first measurable snowfall of the season totaled 3.1 inches. North winds to 20 mph were recorded on the 23rd. This was the only measurable snow of the month.
In 1932…post-frontal snowfall from the late evening of the 23rd continued through the late afternoon of the 24th and totaled 6.2 inches. Southeast winds were sustained to 25 mph with gusts to 26 mph on the 23rd. Temperatures cooled from a high of 68 degrees on the 23rd to a low of 25 degrees on the 24th…the coldest reading of the month that year. Many trees that had not shed their leaves became heavily laden by the wet snow. Many branches were broken… And a few trees toppled under the weight of the snow. The landscape became one of rare beauty.
In 1956…southwest winds gusted to 56 mph and produced some blowing dust at Stapleton Airport. A cold front produced a thunderstorm with 1/8 inch hail. Rain later changed to snow. Precipitation totaled only 0.11 inch and snowfall only 0.3 inch.
In 1973…strong winds raked the eastern foothills…causing damage in Boulder and Jefferson counties. The heaviest damage occurred in the Boulder area where 20 to 25 mobile homes were hit…some power and telephone lines were blown down…and a store was damaged. A wind gust to 76 mph was recorded in Boulder at the National Bureau of Standards. Northwest winds gusted to 46 mph at Stapleton International Airport.
In 1921…rainfall totaled 0.35 inch overnight behind an apparent cold front. North winds were sustained to 40 mph with gusts to 46 mph on the 25th. Temperatures plunged from a high of 73 degrees on the 24th to a low of 39 degrees on the 25th.
In 1923…rain overnight changed to snow during the morning. The heavy snowfall accumulated to 12.0 inches before ending on the morning of the 25th. Post-frontal north winds were sustained to 22 mph with gusts to 23 mph on the 24th.
In 1997…one of the worst and deadliest blizzards of the decade developed over eastern Colorado as deep east to northeast flow associated with a vigorous upper level low pressure system over the four corners…combined with a strong arctic air mass over the central great plains. Snowfall totals across metro Denver ranged from 14 to 31 inches. The heaviest snowfall occurred in the foothills west and southwest of Denver where 2 to 4 feet of snow were measured. Sustained winds to 40 mph with gusts as high as 60 mph produced zero visibilities and extremely cold wind chill temperatures from 25 below to 40 below zero. Winds whipped the snow into drifts 4 to 10 feet deep. Several major and interstate highways were closed as travel became impossible. Red Cross shelters were set up for hundreds of travelers who became stranded when they had to abandon their vehicles. Four people died in northeastern Colorado as a result of the blizzard. None of the deaths were in metro Denver. At Denver International Airport…4 thousand travelers were stranded when the airport was forced to shut down. At least 120 cars were abandoned along Pena Blvd….the only arterial leading into and out of DIA. The blizzard cost air carriers at least 20 million dollars. Thousands of cattle died in the storm over northeastern Colorado…resulting in losses totaling 1.5 million dollars. Some of the more impressive snowfall totals included: 51 inches at Coal Creek Canyon; 48 inches at Silver Spruce Ranch…near Ward; 42 inches at Intercanyon…in the foothills southwest of Denver; 37 inches at Sedalia; 35 inches at Aspen Springs and Conifer in the foothills west of Denver; 31 inches at Eldorado Springs… Southeast Aurora…and Englewood; and 30 inches on Table Mesa in Boulder. Snowfall totaled 21.9 inches at the site of the former Stapleton International Airport…setting a new 24-hour snowfall record of 19.1 inches for the month. Snowfall totaled only 14 inches at Denver International Airport where north winds gusted to 39 mph on the 24th. High temperature of only 21 degrees on the 25th equaled the record low maximum for the date first set in 1873. Low temperature of only 3 degrees on the 26th set a new record minimum for the date.
In 1925…a vigorous cold front produced north winds sustained to 42 mph with gusts to 52 mph. Post-frontal snowfall was only 0.4 inch during the late afternoon and early evening.
In 1959…northwest winds gusted to 55 mph at Stapleton Airport.
In 1997…the high temperature warmed to only 21 degrees…the record low maximum for the month. The same temperature also occurred on October 30…1991.
In 2010…very strong winds during the day knocked down power lines in parts of Boulder. The downed electrical lines sparked a small brush fire near columbine elementary school. Strong wind gusts also damaged the tennis bubble at the Millennium Harvest House in Northglenn. A tree was knocked down and caused minor damage to a mini-van parked nearby. Peak wind gusts included: 70 mph at Berthoud…67 mph at Rocky Mountain Metropolitan Airport in Broomfield… 63 mph at the Rocky Flats National Wind Technology Center and 59 mph at the NCAR Mesa Laboratory…3 miles southwest of Boulder. West winds gusted to 43 mph at Denver International Airport.
In 2011…a powerful early season storm brought heavy snow to the Front Range and adjacent plains. The heavy…wet snow caused extensive downed large branches and in some cases…entire trees. Massive power outages occurred from Fort Collins and greeley south to Denver and the surrounding metro area. Most of the trees still had their leaves…which helped to catch snow and down trees under the weight of the moisture laden snow. Nearly two hundred thousand utility customers along the Front Range were without heat and electricity for several hours. The Red Cross opened four temporary shelters overnight until the power could be restored. The outages also forced the closure of the Boulder criminal justice center the following day. The fallen trees and branches also caused extensive property damage to roofs and automobiles. In the Front Range mountains and foothills…storm totals included 19.8 inches…3 miles west of Jamestown; 18 inches…5 miles west of copper; 13 inches…3 miles north of Blackhawk and 3 miles south of Evergreen…4 miles east-northeast of Nederland and Lake Eldora; 12 inches at Berthoud SNOTEL. Across the urban corridor storm totals included: 11.5 inches in Boulder; 9.5 inches at the national weather service in Boulder; 9 inches…1 mile southwest of Westminster; 8.5 inches in Broomfield… Denver International Airport…Frederick and Louisville; 8 inches in Aurora…7 inches in Watkins; with 6 inches in Arvada.
In 1996…4 to 6 inches of snow fell in the foothills west of Denver. Only 1.5 inches of snowfall were measured at the site of the former Stapleton International Airport on the 26th. This was the only measurable snow of the month at the site. The snowfall produced icy and snowpacked highways…which resulted in a 50-to 60-car pileup on I-25 south of metro Denver. West winds gusted to 33 mph at Denver International Airport.
In 2006…a winter storm brought heavy snowfall to metro Denver and the eastern foothills. Total snowfall ranged from 12 to 22 inches over the higher terrain and 6 to 12 inches across metro Denver. Northerly winds at sustained speeds of 20 to 30 mph with gusts as high as 47 mph at Denver International Airport whipped the snow into drifts 3 to 4 feet deep. Many tree limbs snapped under the weight of the heavy…wet snow which also downed power lines… Leaving thousands of residents without power. Storm total snowfall included: 25 inches near Aspen Springs…Conifer… And Evergreen; 23.5 inches near Rollinsville; 23 inches in Idaho Springs; 22.5 inches near Blackhawk; 21.5 inches near Bailey; 19 inches near Bergen Park; 18 inches near Aspen Springs…Genesee…and Jamestown; 17 inches southwest of Boulder; 16 inches in Evergreen; and 15 inches near Georgetown and Perry Park. Snowfall totaled 5.3 inches in the Denver Stapleton area. At Denver International Airport…rain…including a thunderstorm…changed to snow on the evening of the 25th after a high temperature of 70 degrees.
In 2010…a storm system brought heavy snow to the mountains west of Denver. Storm totals included: 24 inches at the Eisenhower Tunnel…18 inches at Loveland Ski Area; with 16 inches at Arapahoe basin.
In 1897…a major storm dumped 13.5 inches of snowfall over downtown Denver. Rain changed to snow during the evening of the 25th and continued through mid-morning of the 27th. Most of the snow…12.0 inches…fell on the 26th when north winds were sustained to 36 mph and gusts were as high as 46 mph. Temperatures during the storm were in the 20’s and lower 30’s. Precipitation (rain and melted snow) totaled 1.21 inches.
In 1995…winds gusting from 100 to near 110 mph pounded the foothills northwest of Denver. At Nederland winds gusted to 100 mph and to 70 mph in Coal Creek Canyon. Atop Squaw Mountain west of Denver wind gusts to 108 mph were recorded. The strong winds downed some trees and caused power outages. West-northwest winds gusted to 47 mph at Denver International Airport.
In 1971…strong winds raked Boulder. At the National Bureau of Standards wind gusts to 62 mph were recorded…while in downtown Boulder winds peaked to 48 mph. At Stapleton International Airport…northwest winds gusted to 38 mph on the 26th and north winds gusted to 36 mph on the 27th.
In 1976…the first measurable snow of the season turned into a major storm. Traffic was halted for several hours on highways to the west of Denver where 8 to 12 inches of snow fell in the foothills. Snowfall totaled 7.2 inches at Stapleton International Airport where north winds gusted to 30 mph. Most of the snow…6.3 inches…fell all day on the 26th. The greatest snow depth on the ground was 5 inches on the morning of the 27th.