As we move further into the severe weather season, we begin to see that transition in our look back at Denver weather history.  There are many more mentions of lightning, wildfires, tornadoes, hail and other season weather conditions.

14-18

In 1996…a period of unusually warm weather resulted in 4 record maximum temperatures in 5 days.  The record high temperatures were 87 degrees on the 14th…89 degrees on the 15th…and 93 degrees on both the 16th and 18th.  The temperature climbed to only 81 degrees on the 17th which was not a record.

16-17

In 1981…a heavy rain storm dumped 1 to 2 1/2 inches of rain across metro Denver.  Rainfall totaled 1.27 inches at Stapleton International Airport where north winds gusted to 38 mph on 17th.

In 1983…a very strong late spring storm dumped heavy snow over the Front Range.  Strong winds with the storm produced blizzard conditions at times.  Sustained winds were 20 to 40 mph with a peak gust to 55 mph at Stapleton International Airport.  The foothills received 1 to 2 feet of snow with 4 to 12 inches along the foothills.  Howling winds whipped the snow into drifts several feet deep…closing schools and highways.  Stapleton International Airport was forced to reduce flight operations…closing 2 of 4 runways and stranding hundreds of travelers.  Most of the damage and inconvenience caused by the storm was in power outages… Which occurred when wind and heavy wet snow caused hundreds of power poles to snap and topple.  About 20 square miles of Denver were blacked out.  Precipitation from the storm totaled 1 to 3 inches.  At Stapleton International Airport… Snowfall totaled 7.1 inches with a maximum snow depth on the ground of only 2 inches due to melting.  The high temperature of 40 degrees on the 17th was a record low maximum for the date.  Due to the heavy moisture content of the storm…widespread street flooding occurred on the 18th when much of the snow melted under the warm May sun and temperatures climbed to a high of 57 degrees.

In 1995…significant moisture and upslope flow caused flooding across metro Denver.  Moderate to heavy rains… Which began on the evening of the 16th…developed in the foothills and spread eastward over metro Denver throughout the night.  The heavy rains brought many creeks and small streams to bankfull or slightly over.  Locations along the foothills received between 3 and 4 inches of rainfall from the storm.  Boulder received 3.60 inches of rainfall for the 24-hour period…causing minor street flooding near small streams.  To the northwest of Boulder…a bridge which crossed Fourmile Creek was washed out.  Numerous rock and mudslides occurred in foothills canyons…closing portions of U.S. Highways 6 and 40 and State Highway 119 for a few hours at a time.  Rocks were piled 6 feet deep on a stretch of State Highway 119 along with Boulders as large as cars on U.S. Highway 6.  A parking lot near a creek in Golden caved in leaving a hole the size of an 18-wheeler.  Rushing water washed out a 50-foot stretch of a road in Westminster. Rainfall totaled 1.75 inches at Denver International Airport…but only 1.42 inches at the site of the former Stapleton International Airport.

17

In 1903…southwest winds were sustained to 42 mph with gusts to 45 mph from an apparent microburst which produced only a trace of rain.

In 1960…hail to 3/4 inch diameter was measured in Thornton. Golf ball size hail fell in Arvada.

In 1972…microburst winds gusted to 51 mph at Stapleton International Airport.

In 1975…hail 1/2 to 3/4 inch in diameter fell over western metro Denver.

In 1978…a small tornado touched down in south Aurora damaging 40 homes…6 to a considerable extent.  One garage was demolished and blown across the street.  Parts of roofs were completely blown away.  Several 2×4-inch boards were blown into the sides of houses.  Another small tornado in Parker damaged two airplanes.  Other funnel clouds were sighted over Northglenn and near Golden.

In 1985…a thunderstorm produced a total of 1.50 inches of rain in Brighton where 0.72 inches fell in 40 minutes. Small hail covered the ground…and there was some street and basement flooding.

In 1987…small hail piled up 4 inches deep in southwest Aurora.  There was also widespread street flooding and a few power outages.  Hail as large as 3/4 inch in diameter fell at Castle Rock.

In 2000…high winds occurred along and east of the Front Range foothills…as a deep surface low pressure center formed over the northeast plains of Colorado.  An amusement park in north Boulder received about 25 thousand dollars in property damage.  Peak wind reports included:  88 mph at the national wind technology center…84 mph in Boulder…and 80 mph at the National Center for Atmospheric Research Mesa Laboratory. A powder keg of severe weather…including tornadoes and thunderstorms producing large hail…damaging winds and heavy rain…occurred over the plains to the northeast of Denver.  The only severe weather reported across metro Denver was 1 inch diameter hail in Littleton.

17-19

In 2017…a strong spring storm dropped across the Great Basin… and then moved eastward across Colorado. Isolated but strong thunderstorms preceded the system on the 17th with hail up to nickel size near Boulder Airport and Brighton. Significant snow fell across the Front Range mountains and foothills over the next couple of days. Along the Interstate 25 Corridor… rain turned to snow on the morning of the 18th…heaviest from around Broomfield northward. The heavy wet snow snapped the limbs of fully leaved trees and caused scattered power outages. A barns collapsed in northeast Loveland. Fifty-five head of cattle were inside the collapsed barn; three were injured and later euthanized. Numerous branches and trees snapped in the foothills. Elsewhere…several scattered smaller power outages were reported. Three to nearly five inches of liquid precipitation occurred…as rain or a mix of rain and snow…fell around Greeley. Storm totals in the Front Range mountains and foothills included: 42.0 inches near Allenspark…41.5 inches near Ward…36 inches at Estes Park… 32 inches near Pinecliffe…30.5 inches northwest of Golden… 30 inches near Nederland…26 inches near Breckenridge…25 inches near Aspen Springs and Bear Lake State Park…14 inches at Aspen Springs…with 9.5 inches near Evergreen. On the west side of the Interstate 25 Corridor…storm totals included: 10 inches near Superior and Louisville…6 to 8 inches in and around Fort Collins…6 inches in Lafayette… 5 inches in Broomfield and Loveland…and 4 inches near Niwot.

18

In 1864…heavy rains combined with melting snow to cause much flooding on north clear creek in Blackhawk.  Many bridges on the road to Denver were washed away by the high water on clear creek.

In 1893…northwest winds were sustained to 56 mph with an extreme velocity to 60 mph.

In 1960…large hail to 1 inch in diameter damaged roofs and cars in metro Denver.  Heavy snow and rain in the foothills caused rock and landslides…which blocked some highways. There was widespread minor damage from lightning. Hail as large as 1 1/8 inch in diameter was measured at Stapleton Airport where winds gusted to 44 mph.

In 1975…a tornado touched down briefly just south of Buckley Field in Aurora.  A few minutes later the same tornado touched down in open country 8 miles northeast of Stapleton International Airport.  No damage was reported.

In 1985…3/4 inch hail fell just southeast of Aurora.

In 1988…lightning started a fire at a home in the foothills west of Boulder…causing 50 thousand dollars in damage.

In 1995…strong thunderstorms rumbled across metro Denver dropping mainly pea to marble size hail.  However…hail stones as large as 1 1/4 inches in diameter fell in Wheat Ridge and downtown Denver.  Hail piled up to 2 inches deep in Wheat Ridge and northwest Denver.

In 1996…the Buffalo Creek Wildfire started and spread rapidly on strong southwest winds at 20 to 30 mph.  Dry weather conditions contributed to the spread of the fire… Which burned nearly 12 thousand acres and destroyed 12 structures including some houses.

In 2001…a 19-year-old man was struck and killed by lightning as he was walking along the shoulder of U.S. Highway 36 in Westminster.

In 2003…hail to 3/4 inch in diameter was measured at Denver International Airport.

In 2010…a small tornado touched down near Firestone but did no damage.

18-19

In 2011…a severe thunderstorm in central Adams County produced large hail and heavy rainfall on the 18th. Large hail from 1 inch to 1 3/4 inches in diameter…was reported in Commerce City…2 miles south-southeast of Federal Heights…Northglenn… And 2 miles south of Thornton. In Commerce City…the storm uprooted trees and knocked out power lines. A carport was lifted off the ground and struck the power lines overhead. Heavy rain…from 1.0 to 1.5 inches fell in less than 2 hours in Commerce City and near Brighton. The combination of hail and strong winds broke windows in Northglenn. In the foothills…moderate to heavy snow showers developed overnight. Storm totals included: 10.5 inches at gold hill…9.5 inches… 3 miles west of Jamestown; 9 inches at Lake Eldora; with 6 inches… 11 miles southwest of Gilpin and 4 miles east-northeast of Nederland. At Denver International Airport…total rainfall over the 2-day period totaled 1.71 inches. In addition…a peak wind gust to 37 mph was recorded on the 18th.

18-20

In 1915…3.9 inches of snow fell in the city.  The estimated amount of snow that melted as it fell was 6.2 inches which would have totaled an estimated 10.1 inches of snowfall. Precipitation totaled 1.03 inches.  North winds were sustained to 32 mph on the 18th.  Low temperatures dipped to 25 degrees on both the 18th and 20th…establishing record minimums for both dates.

In 1988…prolonged heavy rainfall drenched metro Denver. The event began when heavy thunderstorms on the 18th caused some street flooding and power outages…followed by steady rain on the 19th and 20th.  Rain amounts across metro Denver totaled 3 to 4 inches.  Rainfall totaled 3.71 inches at Stapleton International Airport where north winds gusted to 39 mph on the 20th.  Four to eight inches of snow fell in the foothills above 7 thousand feet.

Continue reading May 17 to May 23: This week in Denver weather history →

As we move further into spring we begin to less winter-like weather and more spring weather.  In looking at Denver weather history we can see that transition with more mentions of severe rains, flooding, tornadoes and other spring and summer-like severe weather.

From the National Weather Service:

8-10

In 1979…4.3 inches of snow fell at Stapleton International Airport where northwest winds gusted to 30 mph on the 8th. Most of the snowfall…2.3 inches…occurred on the 9th. High temperature of only 35 degrees on the 9th equaled the record low maximum for the date.

9-10

In 1889…heavy rainfall totaled 2.15 inches in downtown Denver.  The cold rain was mixed with snow at times overnight.  Temperatures on the 10th ranged from a high of 38 degrees to a low of 32 degrees with north winds sustained to 22 mph.

In 2003…a late spring snowstorm hammered the mountains… Eastern foothills…and urban corridor.  The heaviest snowfall occurred north of interstate 70.  The heavy wet snow caused damage to trees throughout metro Denver and downed power lines.  About 40 thousand people along the urban corridor were without power.  Storm total snowfall amounts included:  11.5 inches in Louisville… 8 inches in Boulder and Broomfield; 7 inches in Thornton…Broomfield…at Denver International Airport… And at the site of the former Stapleton International Airport; and 6 inches 4 miles east of Denver.  Snowfall ranged from 4 to 9 inches across extreme southern weld County.  In the foothills…15 inches of snow fell near Jamestown…9 inches at Rollinsville and Rawah…with 8 inches at Chief Hosa and atop Lookout Mountain. The snow was accompanied by thunder on the afternoon of the 9th at Denver International Airport where west winds gusted to 25 mph on the 9th and north winds gusted to 22 mph on the 10th.

In 2015…from the 9th to the 10th…a strong storm system brought heavy snow to areas in and around Denver. Moderate to heavy rain showers transitioned over to snow by early in the evening on the 9th. Heavy wet snow overnight caused many trees to break under the pressure of the sudden weight. Tree damage ranged from minor to significant…with old growth trees losing large limbs and new trees sustaining fatal damage. Power outages affected about 43350 Xcel Energy customers in metro Denver. The Intermountain Rural Electric Association also reported about 1000 power outages in the Strasburg areas. In the high country…CDOT shut down Interstate 70 between the Eisenhower Tunnel and Silverthorne due to multiple crashes.

10

In 1875…a windstorm sand-blasted the city from 10:00 am until midnight.  Northwest winds sustained to 60 mph brought clouds of sand…which caused high damage to unfinished buildings.

In 1912…a vigorous cold front produced strong north winds and rain.  North winds were sustained to 48 mph with gusts as high as 60 mph.  Rainfall totaled 1.10 inch.

In 1935…no precipitation occurred…making this one of only two days without precipitation during the entire month.  The other day was the 21st.  Precipitation totaled 4.95 inches for the month.

In 1956…northwest winds gusted to 53 mph at Stapleton Airport where the visibility was briefly reduced to 1/2 mile in blowing dust.

In 1974…strong winds caused 30 thousand dollars in damage to a building under construction in Lakewood.  Microburst winds gusted to 46 mph at Stapleton International Airport.

In 1988…lightning struck a house in Boulder…setting it afire.  The house…valued at 170 thousand dollars…was a total loss.

In 1989…golf ball size hail fell over southeast Denver near the junction of I-25 and I-225.  Hail to 3/4 inch in diameter fell over southeast Aurora.  Only 3/8 inch hail fell at Stapleton International Airport.

In 1991…high winds up to 63 mph raked the eastern foothills. Winds estimated to 50 mph tore a roof from a home in Lafayette.  A tower at Jefferson County stadium in west metro Denver was blown over by the high winds.  No injuries were reported.  Southeast winds gusting to 48 mph at Stapleton International Airport produced some blowing dust.  The temperature climbed to a high of 86 degrees… Equaling the record maximum for the date.

In 2005…severe thunderstorms produced hail as large as 2 inches in diameter in and near Longmont.

10-11

In 1918…post-frontal snowfall totaled 4.7 inches in downtown Denver.  Northwest winds gusted to 19 mph on the 10th.

In 1923…winds were strong and gusty on both days.  Northwest winds were sustained to 40 mph with gusts to 44 mph on the 10th.  North winds were sustained to 39 mph with gusts to 46 mph behind an apparent cold front on the 11th.

10-12

In 2011…a spring snowstorm brought heavy snow to the Front Range foothills and palmer divide. Storm totals included: 18 inches…4 miles south-southeast of Pinecliffe; 16 inches in Coal Creek Canyon; 15 inches…4 miles west-southwest of Eldorado Springs; 13 inches at Gold Hill…12 inches… 4 miles west-southwest of Conifer and 4 miles northwest of Elizabeth; 11.5 inches…6 miles southwest of Evergreen and 4 miles east-northeast of Nederland; 11 inches…3 miles east of Jamestown and 10.5 inches…3 miles east of Franktown and 3 miles south of Golden and 10 inches…10 miles north of Elizabeth. At Denver International Airport… 1 inch of snowfall was observed.

11

In 1879…an apparent cold front during the afternoon produced sustained north winds as high as 60 mph and great clouds of blowing dust.  The dust filled the air until the thunderstorm rain began…which produced 1.46 inches of rainfall.  The rain ended during the evening.

In 1900…southwest winds were sustained to 40 mph with gusts to 46 mph.

In 1958…a microburst caused a brief wind gust to 55 mph at Stapleton Airport.

In 1963…south-southwest winds gusted to 48 mph at Stapleton Airport.  Winds May have been stronger over west Denver where some buildings were damaged.

In 1998…large hail fell over south metro Denver.  Hail as large as 1 1/4 inches in diameter was measured in Parker with 1 inch hail recorded in Littleton and 4 miles south of Lakewood in Jefferson County.  Hail to 3/4 inch diameter was measured in Douglas County…11 miles west- northwest of Parker.

11-12

In 2014…a strong storm system moved from southwest Colorado and produced heavy snow in and near the Front Range foothills and metro Denver. The snow was heaviest in the foothills where up to 2 1/2 feet of snow was observed. In the foothills… Storm totals included: 30 inches near Pinecliffe; 29 inches… 8 miles northeast of Four Corners; 28 inches near Pingree Park; 27 inches near Allenspark; 20.5 inches near Idaho Springs; 19.5 inches at Gold Hill; 19 inches near Genesee; 18 inches near Blackhawk; 17 inches at Aspen Springs; 16.5 inches near Ward; 13.5 inches at bergen park; with 11 inches at Evergreen. Along the urban corridor and Palmer Divide…storm totals included: 10.5 inches at Eldorado Springs; 10 inches at Ken Caryl; 9 inches at Superior; 8 inches near Morrison; 7.5 inches in Broomfield and Highlands Ranch; 7 inches in Denver… Near Franktown…Golden… Lakewood and Highlands Ranch; 6 inches…5 miles northeast of Westminster… 7 miles south of Lyons and near Parker; with 5.5 inches at Aurora. At Denver International Airport…1.1 inches of snowfall was observed… Along with 0.9 inches of water.

12

In 1875…two forest fires on the eastern slope of the foothills were visible from the city.

In 1904…north winds were sustained to 40 mph with gusts to 48 mph.

In 1950…brilliant and complete primary and secondary rainbows arching across the sky were observed from Stapleton Airport.

In 1951…a wind gust to 51 mph was recorded at Stapleton Airport.

In 1984…winds gusted to 69 mph in Boulder.  Northwest winds gusted to 47 mph at Stapleton International Airport.

In 1987…a small weak tornado touched down for about 2 minutes in southeast Denver.  The twister hit a car dealership…blowing about a dozen windows out of cars and shattering four skylights on the building.  Some tin roofing was blown off a patio a block and a half away.  The tornado also downed a power pole.  Damage at the dealership was estimated at 10 thousand dollars.  A man was slightly injured by lightning in northwest Aurora.

In 1995…several funnel clouds were sighted near Parker. One of the funnels produced a short-lived debris cloud on the ground in an open field.  No damage was reported.

In 2015…a man suffered minor injuries when the tree he took shelter under was struck by lightning. He was jogging at City Park Golf Course when the incident occurred. The jogger was taken to the hospital for observation.

12-13

In 1907…the temperature warmed to a high of 73 degrees on the 12th…before a cold front produced a thunderstorm… Northeast winds sustained to 40 mph…and rain changing to light snow overnight.  Snowfall totaled only 2 inches…but the high temperature on the 13th was only 39 degrees.

In 1961…a storm that covered metro Denver with rain and snow started as thunderstorms on the evening of the 12th.  Hail to 1 1/2 inches in diameter was reported 10 miles northwest of Stapleton Airport.  Rain continued overnight and changed to snow on the 13th.  Snowfall totaled 6.4 inches and precipitation (rain and melted snow) 1.96 inches at Stapleton Airport where north winds gusted to 39 mph.  The rain and heavy wet snow caused icing damage to utility lines.  Heavy snow occurred in the foothills.

In 1982…a major storm dumped 1.50 to 3.50 inches of rain across northeast Colorado and deposited prodigious amounts of snow in the foothills.  Coal Creek Canyon southwest of Boulder was buried under 46 inches of snow with 39 inches at Nederland.  The heavy wet snow downed many powerlines in the foothills.  In Thornton…the roof of a school was damaged by water from the heavy rain.  At Stapleton International Airport…1.49 inches of rain were measured over the two day period.  The heavy rain ended a severe and prolonged drought.

In 2004…a winter storm produced heavy snow in excess of a foot in the foothills above 6 thousand feet while heavy rain fell across the city.  The heaviest snow occurred in the high country of Boulder County.  Storm total snowfall was 14.5 inches near Jamestown.  Rainfall totaled 0.81 inch at Denver International Airport with 0.94 inch recorded at Denver Stapleton.  A trace of snow was recorded at both locations.  East winds gusted to 24 mph at Denver International Airport on the 12th.

13

In 1905…a thunderstorm produced hail during the late afternoon.  Precipitation totaled 0.57 inch.

13-14

In 1912…heavy snowfall totaled 12.4 inches over the city. Most of the snow…9.9 inches…fell on the 13th…which was the greatest 24 hour snowfall in May at the time.  This was the last snowfall of the season.  The low temperature dipped to 27 degrees on the morning of the 14th.

In 1989…a spring storm brought heavy rain and snow to the foothills.  Metro Denver was soaked with 1 to 2 inches of rain.  Rainfall totaled 1.26 inches at Stapleton International Airport.  In the foothills…Echo Lake received 20 inches of snow.  A 30-ton Boulder slid onto I-70 east of the Eisenhower Tunnel…closing the freeway for 2 hours.

14

In 1910…a thunderstorm produced strong winds during the afternoon.  Northwest winds were sustained to 42 mph.

In 1913…light moist snow and light hail fell during short intervals…although no thunder was heard.  The trace of snowfall was the only snow of the month.  Precipitation… Mostly rain…totaled 0.44 inch.

In 1984…a pilot reported a tornado 16 miles east of Stapleton International Airport.  No damage was reported. A thunderstorm produced a 58 mph wind gust in Brighton. Thunderstorm winds gusted to 48 mph at Stapleton International Airport.

In 1989…lightning struck a home in evergreen…setting it afire.

In 1992…strong thunderstorm winds of unknown velocity… Knocked over and damaged the infield tote board at Arapahoe Park Racetrack just southeast of Aurora. Damage was estimated at 200 thousand dollars.  No injuries were reported.  Lightning started two house fires…causing 35 hundred dollars in damage in Adams County just 9 miles north-northwest of Denver.

In 1994…a sudden wind gust…estimated at 40 mph…blew a portion of the roof off a shopping center in Lafayette. The roof also damaged two parked cars in an adjacent lot.

In 2001…a construction worker in Castle Rock received minor injuries when lightning struck close-by.

In 2002…a microburst wind gust to 53 mph was recorded at Denver International Airport.

In 2007…severe thunderstorms producing large hail…very heavy rain…and tornadoes impacted the urban corridor and adjacent plains.  Heavy rain associated with a severe thunderstorm caused flooding along a small tributary draining into the South Platte River.  The incident took place at 13th and Decatur St….near Invesco Field.  The floodwaters inundated the bike trail adjacent to the creek. A woman with her child sought refuge under a bridge and became trapped by the high water.  The woman slipped and the stroller containing the child was swept into the swift current.  The child drowned.  Rainfall totaled 0.42 inches at Denver International Airport.  Elsewhere…golfball hail was reported near Hudson.  Hail…up to one inch in diameter…was observed in Boulder and Lyons. Thunderstorm wind gusts estimated to 70 mph were reported near Buckley Air Force Base…with a peak wind gust to 37 mph observed at Denver International Airport.  A small tornado touched down near Ft. Lupton but did no damage.

14-15

In 1977…high winds up to 100 mph felled hundreds of trees in Gilpin County and caused extensive damage to telephone and power lines.  Lumber and steel tanks were blown around in Boulder canyon.  West winds gusted to 46 mph at Stapleton International Airport on the 15th.

14-18

In 1996…a period of unusually warm weather resulted in 4 record maximum temperatures in 5 days.  The record high temperatures were 87 degrees on the 14th…89 degrees on the 15th…and 93 degrees on both the 16th and 18th.  The temperature climbed to only 81 degrees on the 17th which was not a record.

Continue reading May 10 to May 16: This week in Denver weather history →

A very eventful week in Denver weather history. Four tornadoes are mentioned and many reminders that winter may not be over just quite yet.

From the National Weather Service:

1-5

In 1898…snowfall totaled 15.5 inches in downtown Denver. Most of the snow…6.2 inches… Fell on the 3rd. Most of the snow melted as it fell. The greatest snow depth on the ground was only 2.5 inches on the 3rd at 8:00 pm. This was the only snowfall during the month. Northeast winds were sustained to 22 mph on the 1st.

2-3

In 1979…heavy rain changed to snow on the 2nd. Snowfall totaled 3.9 inches at Stapleton International Airport… Where northwest winds gusted to 26 mph. The greatest depth of snow on the ground was only 1 inch at midday on the 2nd due to melting. Total precipitation for the 2 days was 1.65 inches.

2-4

In 1987…a slow moving storm brought rain…wind… And snow to metro Denver. Rainfall totaled 1.04 inches at Stapleton International Airport where north winds gusted to 48 mph on the 3rd. The foothills received 5 to 10 inches of snow.

2-5

In 2001…a very slow moving pacific storm system became parked near the Four Corners region…which allowed heavy snow to develop above 6500 feet in the foothills with a mix of rain and snow over lower elevations of metro Denver. Snowfall totals included: 21 inches atop Crow Hill and at Idaho Springs; 19 inches near Blackhawk; and 18 inches in Coal Creek Canyon…Genesee… And 11 miles southwest of Morrison. Snowfall totaled 6.2 inches at the site of the former Stapleton International Airport. Precipitation (rain and melted snow) totaled 2.09 inches at Denver International Airport where north winds gusted to 30 mph on the 2nd.

3

In 1898…heavy snowfall of 6.2 inches fell over downtown Denver. Most of the snow melted as it fell. The greatest snow depth on the ground was 2.5 inches during the evening.

In 1907…the all-time lowest recorded temperature in the month of May…19 degrees… Occurred.

In 1925…an apparent microburst produced sustained northeast winds to 44 mph with gusts to 52 mph. Rainfall was only 0.01 inch in downtown Denver.

In 1981…lightning struck 9 golfers at the south suburban golf course. None were injured seriously.

In 1983…hail 1 1/2 inches in diameter fell at Green Mountain west of Lakewood…with 3/4 inch stones reported in Lakewood.

In 1986…a thunderstorm wind gust to 51 mph was recorded at Stapleton International Airport.

3-5

In 1908…rain changed to snow on the evening of the 3rd and continued through the early evening of the 5th. Snowfall totaled 10.0 inches over downtown Denver. This was the last measurable snow of the season. Precipitation totaled 1.51 inches. North winds were sustained to 23 mph on the 3rd…33 mph on the 4th… And 21 mph on the 5th. Three temperature records were set. High temperatures of 30 degrees on the 4th and 38 degrees on the 5th were record low maximum temperatures for the dates. The reading on the 4th was also the all-time record low maximum for the month of May.

In 2007…a slow moving pacific storm system… From the desert southwest…brought a period of unsettled weather to the region. During the 3-day period…locally heavy snow was reported over parts of the Front Range foothills. Storm totals included: 15 inches near Conifer…14.5 inches west of Jamestown…13.5 inches; 6 miles southwest of Evergreen…and 12.5 inches at pine junction. Severe thunderstorms…producing large hail… Up to one inch in diameter were observed in the vicinity of Boulder and Hudson. Lightning struck a residence in Jefferson County. The roof was hit…causing the attic to catch fire. At Denver International Airport…lightning struck a united airlines jet as it was pushing away from the gate. The passengers were taken off the jet and put on another plane.

4

In 1893…northwest winds were sustained to 42 mph.

In 1971…a funnel cloud was sighted 10 miles southwest of Boulder. Hail stones to 1 inch in diameter fell in southeast Denver…but caused only minor damage.

In 2006…a severe thunderstorm produced hail to 1.00 inch in diameter in Aurora near Cheery Creek Reservoir.

In 2010…high winds downed trees and power lines across parts of the Front Range foothills and urban corridor. Downed power lines sparked a 12-acre wildfire near Conifer. In Boulder…Longmont and Louisville… The wind damaged roofs and broke windows and skylights. Peak wind gusts included: 75 mph in northwest Longmont…71 mph at the national wind technology center and 4 miles south- southwest of superior…61 mph at Broomfield and 56 mph in Erie. At Denver International Airport…a peak wind gust to 46 mph was observed.

4-5

In 1986…high winds buffeted the foothills. Wind speeds of 60 to 75 mph were recorded in Boulder. At Stapleton International Airport…west winds gusted to 45 mph on the 4th and to 40 mph on the 5th.

In 2000…a brief warm spell resulted in setting two daily high temperature records. The temperature climbed to highs of 87 degrees on the 4th and 89 degrees on the 5th.

4-8

In 1969…heavy rains caused flooding on Boulder Creek in Boulder…which resulted in one death on the 7th. Flooding also occurred on bear creek in Sheridan and on the South Platte River in Denver. Rain over most of the eastern foothills started late on the 4th and continued with only brief interruptions in many areas until the morning of the 8th. Very high rates of rainfall occurred on the 6th and 7th with the greatest intensities in a band along the foothills from about 25 miles southwest of Denver northward to Estes Park. Storm totals by both official and unofficial measurements exceeded 10 inches over much of this area and were over 12 inches in some localities. Heavy snow fell in the higher mountains and in the foothills later in the period. The saturation of the soil resulted in numerous rock and landslides…and the heavy run-off caused severe damage along many streams and flooding on the South Platte River. Many foothill communities were isolated as highways were blocked and communications disrupted. Roads were severely damaged over a wide area…and a large number of bridges washed out. Many roads were closed due to the danger from falling rocks. A building in Georgetown collapsed from the weight of heavy wet snow. In Boulder…a man drowned when caught by the flooding waters of Boulder Creek…and a patrolman was injured. Rainfall totaled 7.60 inches in Boulder with 9.34 inches recorded at the public service company electric plant in Boulder Canyon. In Morrison…rainfall totaled 11.27 inches in 4 days. Heavy rainfall totaled 4.68 inches at Stapleton International Airport over 3 days from the 5th through the 7th. Rainfall of 3.14 inches was recorded in 24 hours on the 6th and 7th. Downstream flooding continued along the South Platte River until the 12th when the flood crest reached the Nebraska line.

5

In 1903…apparent post-frontal northeast winds were sustained to 48 mph with gusts to 60 mph.

In 1950…a northwest wind gust to 52 mph was recorded at Stapleton Airport.

In 1969…a funnel cloud was observed for 2 to 3 minutes just north of Parker. Two other funnel clouds were sighted in the same area. The public sighted a tornado 15 miles east of Stapleton International Airport. No damage was reported.

In 2012…severe thunderstorms produced damaging hail ranging in size from quarters to golfballs in metro Denver including: Aurora…Centennial…Cherry Creek…Englewood… And southeast Denver. Aurora was hit the hardest…with extensive property damage reported to homes and automobiles.

5-6

In 1907…rain changed to snow on the 5th… Continued through the night…and totaled 3.50 inches. Northeast winds were sustained to 15 mph on the 5th.

In 1917…post-frontal rain changed to heavy snow and totaled 12.5 inches over downtown Denver. Most of the snow… 12.0 inches…fell on the 5th and this was the greatest 24-hour snowfall ever measured during the month of May. This was also the only measurable snow of the month that year. Low temperatures of 27 degrees on the 5th and 23 degrees on the 6th were record minimums for the dates. High temperatures on both days were in the lower 40`s. Southeast winds were sustained to 24 mph with an extreme velocity to 26 mph.

In 1964…high winds gusted to 54 mph in Boulder and to 80 mph at Jefferson County Airport near Broomfield. Wind gusts of 50 to 60 mph were common over all of eastern Colorado. Buildings…power lines…trees… And vehicles were damaged by the wind. South-southwest wind gusts to 54 mph caused some blowing dust at Stapleton International Airport where the visibility was briefly reduced to 2 miles.

In 1973…a heavy driving rain storm with embedded thunderstorms…produced 1 to 5 inches of rain and caused local flash flooding along the east slopes of the Front Range. The greatest flash flooding occurred in metro Denver where rainfall totaled 3.56 inches at Stapleton International Airport. Flooding in metro Denver occurred on Clear Creek and the South Platte River…already swollen from heavy snowmelt. Numerous basements were flooded… Roads and streets were washed out…a bridge was demolished… And miscellaneous other damage was reported. North winds gusted to 39 mph at Stapleton International Airport during the storm. The storm produced major downstream flooding along the South Platte River all the way to the Nebraska border during the next two weeks. One person died and total damage was estimated at around 120 million dollars.

In 1978…heavy wet snow of around 24 inches collapsed an office and hotel building in Boulder. Many cars were abandoned in the city. Denver received 14 inches of heavy wet snow with Evergreen and Golden reporting 12 inches. Snowfall totaled 12.4 inches at Stapleton International Airport with a total accumulation of snow on the ground of 8 inches due to melting. Southeast winds gusted to 23 mph on the 5th. Temperatures both days remained in the lower to mid-30`s.

6

In 1876…heavy snow fell during the night and ended during the morning…but no amount was recorded. Light hail fell briefly during the late afternoon. Precipitation for the day totaled 1.05 inch which would give an estimated snowfall of nearly 11 inches had all of the precipitation been snow.

In 1889…northwest winds were sustained to 45 mph in the city.

In 1893…heavy snow of 8.9 inches fell over downtown Denver. Once on the ground…the snow melted rapidly. This was the only snow of the month. Northwest winds were sustained to 20 mph.

In 1904…west winds were sustained to 45 mph with an extreme velocity to 46 mph.

In 1914…an apparent dry microburst produced sustained north winds to 44 mph with gusts as high as 50 mph.

In 1920…a thunderstorm produced hail and 0.55 inch of rain. The hail of unknown size covered the ground.

In 1921…thunderstorm winds were sustained to 42 mph with gusts to 44 mph. Rainfall was only 0.17 inch.

In 1936…a light to moderate duststorm moved in from the east on southeast winds and lasted most of the day. The dust reduced the visibility to two miles at times. Winds from the northwest sustained to 21 mph swept the dust out of the city during the late afternoon.

In 1966…a funnel cloud was sighted for 7 minutes to the southwest of Stapleton International Airport. The funnel appeared to be picking up dust from the ground…but was too distant to tell. No damage was reported.

In 1968…a thunderstorm wind gust to 53 mph was recorded at Stapleton International Airport.

In 1988…high winds raked the state. Wind gusts ranged from 60 to 80 mph in Boulder…Aurora… And at Centennial Airport. South-southwest winds to 53 mph were recorded at Stapleton International Airport. Across metro Denver…the strong winds knocked windows out of buildings…downed power poles and wires and some fences…unroofed several buildings… And damaged signs.

In 1997…strong winds from a dry microburst blew an empty 18-wheeler on its side in the northbound lane of I-25 north of Denver near the Brighton exit. There were no injuries. West winds gusted to 46 mph at Denver International Airport.

In 2017…lightning struck dangerously close to a woman while she watched a youth baseball game. She felt her legs go numb after a lightning bolt struck the ground.

6-7

In 1873…snowfall totaled 8.9 inches in downtown Denver. Most of the snow fell on the 6th.

7

In 1904…west winds were sustained to 48 mph with gusts to 60 mph. A shower produced 0.16 inch of rain.

In 1953…a microburst caused a brief wind gust to 58 mph at Stapleton Airport.

In 1958…3/4 inch diameter hail fell over south metro Denver… 10 miles southwest of Stapleton Airport.

In 1977…baseball size hail damaged windows in Wheat Ridge. Hail was 4 inches deep on the ground in Arvada. Hail 3/4 to 1 inch diameter fell in Westminster and Kittredge.

In 1990…a fast moving cold front produced wind gusts of 40 to 60 mph. Brighton reported a wind gust to 57 mph…while north wind gusts to 44 mph were measured at Stapleton International Airport.

In 1995…severe thunderstorms struck Aurora. Hail piled 4 to 5 inches deep in the vicinity of Quincy Reservoir in south Aurora. Lightning struck an Aurora police communications tower causing significant malfunction to the primary system. Minor damage was sustained when lightning struck an apartment building. Hail…up to 1 1/4 inches in diameter…while soft and slushy… Accumulated up to 6 inches deep in 15 minutes. Many streets were closed for an hour or more due to flooding caused by heavy rain and melting hail stones. Some trees were stripped of their leaves. Hail as large as 1/2 inch diameter was measured at Denver International Airport where a funnel cloud was sighted.

In 2003…a tornado touched down briefly near Bennett… But did no reported damage.

In 2005…severe thunderstorms produced 3/4 inch hail near Brighton and a thunderstorm wind gust to 60 mph near Fort Lupton.

In 2014…severe thunderstorms produced large hail… From 1 to 1 1/2 inches in diameter…across parts of Arvada…Broomfield… Dacono…Northglenn and Thornton.

In 2015…a severe thunderstorm produced hail…up to walnut size…in Elbert County. A weak tornado touched down briefly near Ft. Lupton.

In 2017…a 37-year-old woman and her horse were killed near Sedalia after lightning hit a nearby tree. A teenage girl was also seriously injured. Damaging microburst winds downed trees and power poles across parts of Adams…Arapahoe…Denver and Douglas Counties. Electrical lines and branches were also snapped causing scattered power outages.

7-8

In 1958…rainfall totaled 2.50 inches at Stapleton Airport.

8

In 1873…a very light rain fell until 5:00 am… When it turned into light snow and sleet and was accompanied by brisk northeast winds. The snow froze as it fell… Breaking the telegraph lines in many places. Precipitation totaled only 0.14 inch in the city.

In 1883…a severe rain and hailstorm struck the city. In 25 minutes the hail was 5 inches deep in the vicinity of the weather office in downtown Denver and reported as deep as 10 to 12 inches in other parts of the city. Gutters were blocked by the hail…and many cellars were flooded. Precipitation from the storm was 1.90 inches with the total for the day recorded at 2.02 inches. The size of the hail was not recorded.

In 1988…a wind gust to 68 mph was recorded at Echo Lake. Northwest winds gusted to 35 mph at Stapleton Airport.

In 1995…high winds of unknown strength blew a camper shell from the back of a pickup truck near Fort Lupton. North winds gusted to 49 mph at Denver International Airport.

In 1996…1 to 2 inch diameter hail was measured in Lochbuie northeast of Denver. Bean size hail fell in Brighton. The large hail fell from severe thunderstorms to the northeast of metro Denver.

In 2003…tornadoes touched down briefly near Brighton… Watkins…and Strasburg… But did no reported damage. Hail to 3/4 inch in diameter was measured near Hudson.

In 2017…severe thunderstorms broke out across Denver and the surrounding metro area and produced large damaging hail…strong winds…heavy rain and flash flooding. Hail up to baseball size…caused extensive property damage to cars…homes and businesses across a large part of Denver and the western suburbs including Arvada…Lakewood and Wheat Ridge. According to the Rocky Mountain Insurance Agency Association…the storm was Colorado’s most expensive insured catastrophe…around $2.3 billion. The group estimated more than 150000 auto insurance claims and 50000 homeowner insurance claims would be filed. Businesses and homes sustained holes in siding along with broken windows and torn screens. Severe thunderstorm producing large hail…strong winds and heavy rain impacted areas around Greeley as well. The high cost incurred from the storm was due to a number of factors including: the size of the hail…the densely populated area…the time of day…the escalating costs to repair high-tech cars…and more expensive homes. Colorado Mills Mall in Lakewood was severely damaged after hail busted skylights and caused flooding inside stores. The common areas and tenant spaces suffered substantial water damage. Extensive damage to electrical systems…mechanical systems… including HVAC and lighting…were expected to keep the mall closed for several months. In Lakewood…the loss in sales tax was projected to be about $350000 per month…which was 3 to 4 percent of the city`s monthly budget. Prestige Imports in Lakewood which sells Audis and Porches…250 to 300 vehicles were impacted by the storm. Some of those vehicles were valued at nearly $200000 each. Significant damage was reported at Lutheran Medical Center after the hailstorm tore through Wheat Ridge. The hospital building and some of the medical office buildings sustained broken windows. The storm also hit the office of the Colorado Bureau of Investigation in Lakewood. The offices were flooded…several cubicles destroyed…and even some ceiling tiles fell off. The storm damage prompted school officials to close all thirteen Adams 12 Five Star schools in Commerce City and Beach Court Elementary school in Denver. Most of the schools in the Adams 12 Five Star District were at least 50 years old and sustained flood damage. Large hail damaged an apartment building near Regis University… shattered windows and punctured the siding on the west- facing side of the building. Hail and heavy rain clogged drains and caused flash flooding throughout Greeley. Up to three feet of water covered the roadway near U.S. 34 and U.S. 85. Greeley firefighters helped several residents get out of garden level apartments that had flooded. Several other businesses and buildings suffered flood damage… including Greeley City Hall and an apartment complex in Evans. The Greeley Mall was extensively damaged when water poured into the mall from the roof and debris inundated the main floor.

8-9

In 1957…intense heavy rain caused flash flooding on toll gate creek in Aurora where 3 people were killed in a car. Up to 4 inches of rain fell in 5 hours in the toll gate creek basin. The rain also caused flash flooding on sand creek in Aurora and Denver. Rainfall totaled 3.29 inches at Stapleton Airport with most of the rain…2.34 inches… Occurring on the 9th.

8-10

In 1979…4.3 inches of snow fell at Stapleton International Airport where northwest winds gusted to 30 mph on the 8th. Most of the snowfall…2.3 inches… Occurred on the 9th. High temperature of only 35 degrees on the 9th equaled the record low maximum for the date.

9

In 1875…a heavy windstorm swept across the city for most of the day. West-northwest winds averaged a sustained speed of 31 mph between 6:00 am and 3:00 pm. The peak wind was sustained to 45 mph at 9:50 am.

In 1918…post-frontal winds were sustained to 40 mph with gusts as high as 43 mph. Only a trace of rain fell.

In 1941…a tornado was noted at 2:20 pm to the northeast of downtown and was followed by another similar shaped cloud or dust roll estimated 3 miles behind. Thick dust followed with heavy gusts of wind. The temperature fell 15 degrees in 10 minutes following the twister. The mild tornado did little damage except to unprotected frame structures. Winds were sustained to 50 mph with the passing of the tornado at Stapleton Airport. It was visible to observers for 10 minutes and was lost from sight as it traveled east into huge rolls of dust. Hail and rain followed with a few hailstones as large as 1/2 inch in diameter downtown. No damage was reported from the hail. Thunderstorm winds sustained to 31 mph produced blowing dust downtown. Precipitation was only 0.07 inch.

In 1983…streams swollen by recent rain and snowmelt caused an earthen dam to collapse…washing out portions of State Highway 67 near Deckers in southern Douglas County.

In 1992…three boys…ages 11…12…and 16… Were struck by lightning while taking cover under a large tree during a thunderstorm in Jefferson County…just 7 miles northwest of Denver. The three were seriously injured.

9-10

In 1889…heavy rainfall totaled 2.15 inches in downtown Denver. The cold rain was mixed with snow at times overnight. Temperatures on the 10th ranged from a high of 38 degrees to a low of 32 degrees with north winds sustained to 22 mph.

In 2003…a late spring snowstorm hammered the mountains… Eastern foothills…and urban corridor. The heaviest snowfall occurred north of Interstate 70. The heavy wet snow caused damage to trees throughout metro Denver and downed power lines. About 40 thousand people along the urban corridor were without power. Storm total snowfall amounts included: 11.5 inches in Louisville… 8 inches in Boulder and Broomfield; 7 inches in Thornton…Broomfield…at Denver International Airport… And at the site of the former Stapleton International Airport; and 6 inches 4 miles east of Denver. Snowfall ranged from 4 to 9 inches across extreme southern weld County. In the foothills…15 inches of snow fell near Jamestown…9 inches at Rollinsville and Rawah… With 8 inches at Chief Hosa and atop Lookout Mountain. The snow was accompanied by thunder on the afternoon of the 9th at Denver International Airport where west winds gusted to 25 mph on the 9th and north winds gusted to 22 mph on the 10th.

In 2015…from the 9th to the 10th…a strong storm system brought heavy snow to areas in and around Denver. Moderate to heavy rain showers transitioned over to snow by early in the evening on the 9th. Heavy wet snow overnight caused many trees to break under the pressure of the sudden weight. Tree damage ranged from minor to significant…with old growth trees losing large limbs and new trees sustaining fatal damage. Power outages affected about 43350 Xcel Energy customers in metro Denver. The Intermountain Rural Electric Association also reported about 1000 power outages in the Strasburg areas. In the high country…CDOT shut down Interstate 70 between the Eisenhower Tunnel and Silverthorne due to multiple crashes.

If history is a teacher, our look back at this week in Denver weather history should provide great instruction on the dangers severe weather presents in our history. It was eight years ago this week that the infamous Windsor tornado tore through the area killing one man and damaging hundreds of homes.

From the National Weather Service:

18-20

In 1915…3.9 inches of snow fell in the city. The estimated amount of snow that melted as it fell was 6.2 inches which would have totaled an estimated 10.1 inches of snowfall. Precipitation totaled 1.03 inches. North winds were sustained to 32 mph on the 18th. Low temperatures dipped to 25 degrees on both the 18th and 20th…establishing record minimums for both dates.

In 1988…prolonged heavy rainfall drenched metro Denver. The event began when heavy thunderstorms on the 18th caused some street flooding and power outages…followed by steady rain on the 19th and 20th. Rain amounts across metro Denver totaled 3 to 4 inches. Rainfall totaled 3.71 inches at Stapleton International Airport where north winds gusted to 39 mph on the 20th. Four to eight inches of snow fell in the foothills above 7 thousand feet.

19-20

In 1864…a devastating major flash flood occurred on the normally dry and sandy Cherry Creek in Denver. The flood was caused by heavy thunderstorm rainfall and hail over the palmer ridge to the south of the city in both the Cherry Creek and Plum Creek basins. Nineteen deaths occurred along the South Platte River and Cherry Creek in Denver. The torrent swept cattle and sheep along with large trees and houses before it washing out several bridges…and moving large structures from their foundations. All city records were destroyed when city hall washed away. The Rocky Mountain News building…built on stilts in the middle of the creek…was totally destroyed by the raging waters…which were as deep as 5 feet on the morning of the 20th. Once the flood waters receded…much sand and gravel was left behind. Property damage from the flood was estimated at nearly one million dollars. This was the first major flood of record in the city.

20

In 1874…after a light late afternoon shower…3 rainbows were visible in the eastern sky. The two upper bows were of the usual colors. The lower bow had a deep violet center with a faint yellow and white rim.

In 1892…apparent post-frontal north winds were sustained to 40 mph with gusts to 48 mph. A trace of snow was the last snowfall of the season.

In 1899…snow pellets from 1/4 to 3/8 inch in diameter fell from a thundershower during the late afternoon. West winds were sustained to 42 mph with gusts as high as 48 mph.

In 1904…southeast winds were sustained to 40 mph with an extreme velocity of 42 mph produced by a thunderstorm.

In 1961…a tornado tore through central Douglas County…1 1/2 miles north of Castle Rock. The storm struck 2 ranches and the property of a drilling company. A car on the highway was lifted off the road and slammed into a truck…injuring the two occupants.

In 1983…heavy rain fell in Aurora with 1.00 to 1.50 inches of precipitation. Local flooding occurred in Lakewood.

In 1990…1 inch diameter hail fell at Buckley Field in Aurora. Minor damage was reported to autos…buildings and signs.

In 1995…hail as large as 3/4 inch in diameter fell near Bennett where a funnel cloud was sighted.

In 2001…damaging winds developed behind a vigorous cold front that moved south from Wyoming into metro Denver. High winds…gusting to 58 mph at Denver International Airport…downed trees and power lines and kicked up blowing dust…dirt…and debris…reducing the visibility to near zero at times. The poor visibility caused a multi-vehicle accident along U.S. Highway 85 north of Fort Lupton. Six people were treated for minor injuries. Several vehicles… Including semi-trailers…were blown off I-70 east of Denver. About 32 thousand Xcel energy customers in metro Denver were without electricity for up to 2 hours. At least a dozen incoming flights at Denver International Airport were diverted to other airports. All departing flights were grounded for at least an hour. At southwest plaza…shoppers were evacuated as rocks holding a tarp on a portion of a roof under repair toppled into the mall. After the passage of the cold front…temperatures plunged from the lower 70’s to the mid 30’s in one hour as light snow developed. Heavy snow developed in the foothills during the evening. Peak wind reports included 68 mph near Parker and 63 mph near Sedalia. Snowfall totals included: 7 inches near Blackhawk… At Ken Caryl Ranch…and near Sedalia; 6 inches in Coal Creek Canyon…at Eldorado Springs…and atop Lookout Mountain; 5 inches at Chief Hosa…in Louisville…Rollinsville…and wheat ridge; and 4 inches in Aurora…Bailey…Parker…Castle Rock and near Morrison. Low temperature of 31 degrees during the early morning of the 21st equaled the record low for the date last set in 1931.

In 2004…severe thunderstorms produced hail as large as 1.25 inches near Ft. Lupton and hail to 1.50 inches 10 miles north of Ft. Lupton.

In 2014…severe thunderstorm produced hail… from 1 to 1 1/4 inches in diameter…across parts of Aurora…Denver… Englewood and Lakewood.

20-21

In 1891…heavy rain was mixed with snow at times and totaled 2.02 inches in the city. Snowfall was 1.0 inch. Northeast winds gusted to 28 mph on the 20th.

20-22

In 1959…a three-day rain caused some flooding in metro Denver where rain totaled 1.68 inches at Stapleton Airport. Showers…accompanied by hail near Brighton…caused some damage to truck crops. Heavy snow in the foothills caused damage to power and telephone lines.

20-27

In 2002…lightning sparked a wildfire near Deckers. Extremely dry conditions and very strong winds the following day allowed the fire…known as the Schoonover…to consume 3850 acres before it could be contained. Thirteen structures were destroyed…including 4 homes…resulting in 2.2 million dollars in damage.

21

In 1874…an extensive fire at Central City in the mountains to the west of Denver produced large columns of smoke that were visible from the city. In the afternoon…the smoke and fire produced a dark inky black convective cloud…which spread over the city and produced brief strong and gusty winds along with a few sprinkles of rain.

In 1880…west winds increased to a sustained velocity of 40 mph during the afternoon.

In 1893…north winds were sustained to 48 mph.

In 1914…a severe thunderstorm was attended by hail…excessive rainfall which totaled 1.94 inches…and an unusual amount of vivid lightning. The heavy rainfall of 0.83 inch in 15 minutes produced flooding…which caused considerable damage to bottom lands in eastern and southern parts of the city. Many garden tracts and cellars were flooded. Southwest winds were sustained to 29 mph with gusts to 34 mph.

In 1935…no precipitation occurred…making this one of only two days without precipitation during the entire month. The other day was the 10th. Precipitation totaled 4.95 inches for the month.

In 1952…a tornado produced a high column of dust and dirt over northwest Denver. No damage was reported.

In 1988…a microburst wind gust to 52 mph was recorded at Stapleton International Airport.

In 2002…very strong winds occurred over metro Denver and northeastern Colorado as a developing surface low pressure center intensified. Trees and branches snapped…downing power lines across parts of metro Denver. About 20 thousand residents lost electricity. The strong winds produced much blowing dust and dirt especially to the northeast of metro Denver. Winds gusted to 61 mph at Parker. South winds gusted to 58 mph at Denver International Airport.

In 2006…a large dust devil formed near Quincy Reservoir in south Aurora. The tall column resembling a tornado or smoke plume extended upward into small high-based cumulus clouds and was visible for miles across southern Aurora and eastern centennial. No damage was reported.

In 2014…severe thunderstorms occurred in and around metro Denver. The storms produced large hail…from quarter to golfball size. Frontier Airlines canceled 16 flights…when several planes sustained hail damage. Forty flights at Denver International Airport were either delayed or canceled. Some homes in Green Valley Ranch…east of Denver… were damaged by hail. Several vehicles were also damaged. Five short lived tornadoes touched down near Bennett and Byers but no damage was reported. The storms also produced heavy rain and strong damaging winds. The wind downed trees and power lines east of Denver. The heavy rain and hail…up to 6 inches deep in spots…caused street flooding around the metro area. The hailstorm at Dicks Sporting Goods Park knocked out power to the stadium where the 4A and 5A girls soccer championship games were about to be played. The inclement weather snarled traffic on Interstate 70…Pena Boulevard… U.S. 85 and elsewhere due to the flooded roads. In some areas…snow plows were called out to clear the hail. Parts of Tower Road and Peoria Street…and other roads in Commerce City… were closed through the late evening hours…because of standing water. Several vehicles stalled in standing water where water pooled in the underpasses. At Denver International Airport…1.2 inches of water was observed…along with a wind gust to 42 mph from the northwest.

21-22

In 1878…overnight heavy rains of cloudburst intensity on the Palmer Divide to the south of the city caused flash flooding on Cherry Creek in Denver…which resulted in 2 deaths. A wall of water swept through the city between 2:00 am and 3:00 am on the morning of the 22nd. The flood was so sudden and unexpected that homes along the creek in the city were submerged in water knee deep before the slumbering occupants knew anything about it. By daybreak the banks on both sides of the creek were lined by residents viewing the destruction caused by the raging waters in such a short time. Seven bridges across the creek were destroyed in the city. Damage to private and city property was estimated between 30 and 50 thousand dollars. Quite a number of cattle and sheep were killed along the reach of the creek. Only 0.01 inch of rain fell in the city on the 21st with a trace of rain on the 22nd. Flash flooding also occurred on Kiowa Creek near Bennett on the night of the 21st when the flood waters washed out the Kansas Pacific Railroad bridge. An east bound freight train plunged into the turbulent waters killing the three crewmen. The locomotive was completely buried in the sand and never found to this day!

Continue reading May 20 to May 26: This week in Denver weather history →

Think we are done with snow for the season? That may be the case this year but it isn’t always so. Looking back at this week in Denver history we do see snowfall has occurred along with more typical spring weather including heavy rains that led to flooding.

From the National Weather Service:

4-8

In 1969…heavy rains caused flooding on Boulder creek in Boulder…which resulted in one death on the 7th. Flooding also occurred on Bear Creek in Sheridan and on the South Platte River in Denver. Rain over most of the eastern foothills started late on the 4th and continued with only brief interruptions in many areas until the morning of the 8th. Very high rates of rainfall occurred on the 6th and 7th with the greatest intensities in a band along the foothills from about 25 miles southwest of Denver northward to Estes Park. Storm totals by both official and unofficial measurements exceeded 10 inches over much of this area and were over 12 inches in some localities. Heavy snow fell in the higher mountains and in the foothills later in the period. The saturation of the soil resulted in numerous rock and land slides…and the heavy run-off caused severe damage along many streams and flooding on the South Platte River. Many foothill communities were isolated as highways were blocked and communications disrupted. Roads were severely damaged over a wide area…and a large number of bridges washed out. Many roads were closed due to the danger from falling rocks. A building in Georgetown collapsed from the weight of heavy wet snow. In Boulder…a man drowned when caught by the flooding waters of Boulder Creek…and a patrolman was injured. Rainfall totaled 7.60 inches in Boulder with 9.34 inches recorded at the Public Service Company electric plant in Boulder Canyon. In Morrison…rainfall totaled 11.27 inches in 4 days. Heavy rainfall totaled 4.68 inches at Stapleton International Airport over 3 days from the 5th through the 7th. Rainfall of 3.14 inches was recorded in 24 hours on the 6th and 7th. Downstream flooding continued along the South Platte River until the 12th when the flood crest reached the Nebraska line.

5-6

In 1907…rain changed to snow on the 5th…continued through the night…and totaled 3.50 inches. Northeast winds were sustained to 15 mph on the 5th.

In 1917…post-frontal rain changed to heavy snow and totaled 12.5 inches over downtown Denver. Most of the snow… 12.0 inches…fell on the 5th and this was the greatest 24-hour snowfall ever measured during the month of May. This was also the only measurable snow of the month that year. Low temperatures of 27 degrees on the 5th and 23 degrees on the 6th were record minimums for the dates. High temperatures on both days were in the lower 40’s. Southeast winds were sustained to 24 mph with an extreme velocity to 26 mph.

In 1964…high winds gusted to 54 mph in Boulder and to 80 mph at Jefferson County Airport near Broomfield. Wind gusts of 50 to 60 mph were common over all of eastern Colorado. Buildings…power lines…trees…and vehicles were damaged by the wind. South-southwest wind gusts to 54 mph caused some blowing dust at Stapleton International Airport where the visibility was briefly reduced to 2 miles.

In 1973…a heavy driving rain storm with embedded thunderstorms…produced 1 to 5 inches of rain and caused local flash flooding along the east slopes of the Front Range. The greatest flash flooding occurred in metro Denver where rainfall totaled 3.56 inches at Stapleton International Airport. Flooding in metro Denver occurred on clear creek and the South Platte River…already swollen from heavy snowmelt. Numerous basements were flooded… Roads and streets were washed out…a bridge was demolished… And miscellaneous other damage was reported. North winds gusted to 39 mph at Stapleton International Airport during the storm. The storm produced major downstream flooding along the South Platte River all the way to the Nebraska border during the next two weeks. One person died and total damage was estimated at around 120 million dollars.

In 1978…heavy wet snow of around 24 inches collapsed an office and hotel building in Boulder. Many cars were abandoned in the city. Denver received 14 inches of heavy wet snow with Evergreen and Golden reporting 12 inches. Snowfall totaled 12.4 inches at Stapleton International Airport with a total accumulation of snow on the ground of 8 inches due to melting. Southeast winds gusted to 23 mph on the 5th. Temperatures both days remained in the lower to mid 30’s.

6

In 1876…heavy snow fell during the night and ended during the morning…but no amount was recorded. Light hail fell briefly during the late afternoon. Precipitation for the day totaled 1.05 inch which would give an estimated snowfall of nearly 11 inches had all of the precipitation been snow.

In 1889…northwest winds were sustained to 45 mph in the city.

In 1893…heavy snow of 8.9 inches fell over downtown Denver. Once on the ground…the snow melted rapidly. This was the only snow of the month. Northwest winds were sustained to 20 mph.

In 1904…west winds were sustained to 45 mph with an extreme velocity to 46 mph.

In 1914…an apparent dry microburst produced sustained north winds to 44 mph with gusts as high as 50 mph.

In 1920…a thunderstorm produced hail and 0.55 inch of rain. The hail of unknown size covered the ground.

In 1921…thunderstorm winds were sustained to 42 mph with gusts to 44 mph. Rainfall was only 0.17 inch.

In 1936…a light to moderate duststorm moved in from the east on southeast winds and lasted most of the day. The dust reduced the visibility to two miles at times. Winds from the northwest sustained to 21 mph swept the dust out of the city during the late afternoon.

In 1966…a funnel cloud was sighted for 7 minutes to the southwest of Stapleton International Airport. The funnel appeared to be picking up dust from the ground…but was too distant to tell. No damage was reported.

In 1968…a thunderstorm wind gust to 53 mph was recorded at Stapleton International Airport.

In 1988…high winds raked the state. Wind gusts ranged from 60 to 80 mph in Boulder…Aurora…and at centennial airport. South-southwest winds to 53 mph were recorded at Stapleton International Airport. Across metro Denver…the strong winds knocked windows out of buildings…downed power poles and wires and some fences…unroofed several buildings…and damaged signs.

In 1997…strong winds from a dry microburst blew an empty 18-wheeler on its side in the northbound lane of I-25 north of Denver near the Brighton exit. There were no injuries. West winds gusted to 46 mph at Denver International Airport.

6-7

In 1873…snowfall totaled 8.9 inches in downtown Denver. Most of the snow fell on the 6th.

7

In 1904…west winds were sustained to 48 mph with gusts to 60 mph. A shower produced 0.16 inch of rain.

In 1953…a microburst caused a brief wind gust to 58 mph at Stapleton Airport.

In 1958…3/4 inch diameter hail fell over south metro Denver… 10 miles southwest of Stapleton Airport.

In 1977…baseball size hail damaged windows in Wheat Ridge. Hail was 4 inches deep on the ground in Arvada. Hail 3/4 to 1 inch diameter fell in Westminster and Kittredge.

In 1990…a fast moving cold front produced wind gusts of 40 to 60 mph. Brighton reported a wind gust to 57 mph…while north wind gusts to 44 mph were measured at Stapleton International Airport.

In 1995…severe thunderstorms struck Aurora. Hail piled 4 to 5 inches deep in the vicinity of Quincy Reservoir in south Aurora. Lightning struck an Aurora police communications tower causing significant malfunction to the primary system. Minor damage was sustained when lightning struck an apartment building. Hail…up to 1 1/4 inches in diameter…while soft and slushy…accumulated up to 6 inches deep in 15 minutes. Many streets were closed for an hour or more due to flooding caused by heavy rain and melting hail stones. Some trees were stripped of their leaves. Hail as large as 1/2 inch diameter was measured at Denver International Airport where a funnel cloud was sighted.

In 2003…a tornado touched down briefly near Bennett…but did no reported damage.

In 2005…severe thunderstorms produced 3/4 inch hail near Brighton and a thunderstorm wind gust to 60 mph near Fort Lupton.

In 2014…Severe thunderstorms produced large hail, from 1 to 1 1/2 inches in diameter, across parts of Arvada, Broomfield, Dacono, Northglenn and Thornton.

7-8

In 1958…rainfall totaled 2.50 inches at Stapleton Airport.

8

In 1873…a very light rain fell until 5:00 am…when it turned into light snow and sleet and was accompanied by brisk northeast winds. The snow froze as it fell… Breaking the telegraph lines in many places. Precipitation totaled only 0.14 inch in the city.

In 1883…a severe rain and hailstorm struck the city. In 25 minutes the hail was 5 inches deep in the vicinity of the weather office in downtown Denver and reported as deep as 10 to 12 inches in other parts of the city. Gutters were blocked by the hail…and many cellars were flooded. Precipitation from the storm was 1.90 inches with the total for the day recorded at 2.02 inches. The size of the hail was not recorded.

In 1988…a wind gust to 68 mph was recorded at Echo Lake. Northwest winds gusted to 35 mph at Stapleton Airport.

In 1995…high winds of unknown strength blew a camper shell from the back of a pickup truck near Fort Lupton. North winds gusted to 49 mph at Denver International Airport.

In 1996…1 to 2 inch diameter hail was measured in Lochbuie northeast of Denver. Bean size hail fell in Brighton. The large hail fell from severe thunderstorms to the northeast of metro Denver.

In 2003…tornadoes touched down briefly near Brighton… Watkins…and Strasburg…but did no reported damage. Hail to 3/4 inch in diameter was measured near Hudson.

8-9

In 1957…intense heavy rain caused flash flooding on toll gate creek in Aurora where 3 people were killed in a car. Up to 4 inches of rain fell in 5 hours in the Toll Gate Creek basin. The rain also caused flash flooding on sand creek in Aurora and Denver. Rainfall totaled 3.29 inches at Stapleton Airport with most of the rain…2.34 inches… Occurring on the 9th.

Continue reading May 6 to May 12: This week in Denver weather history →