A powerful winter storm brought very heavy snowfall to the Front Range Mountains, Foothills, I-25 corridor and northeast plains. Heavy snow developed in and near the Front Range Foothills of Larimer and Boulder counties, then spread south and east across the rest of the region.
Every event with a place to put it; 28 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS BOU wrote it up.
A powerful winter storm brought very heavy snowfall to the Front Range Mountains, Foothills, I-25 corridor and northeast plains. Heavy snow developed in and near the Front Range Foothills of Larimer and Boulder counties, then spread south and east across the rest of the region. All schools were closed on the 25th and 26th across the entire area, including all the major universities and colleges across northeast and north central Colorado. Federal, state, city, and county offices were closed on the 25th. I-70 west of Denver was closed due to a rock slide. I-76 and I-70 northeast and east of Denver were closed for 10 and 7 hours respectively. Other east/west highways including US 34 and US 36, were closed due to blowing and drifting snow. A total of 500 flights were canceled at Denver International Airport.
In the foothills of Larimer County, Buckhorn Mountain received top honors with a storm total of 40.5 inches. Other reports in Larimer County included: 35.5 inches near Glen Haven; 33 inches near Drake; 32 inches, 11 miles southeast of Estes Park and 4 miles east-northeast of Red Feather Lakes. Boulder and Fort Collins reported 22.1 and 17 inches in less than 24 hours respectively; which become the second highest snowfall for those cities in the month of November. At Denver International Airport, the official snowfall measurement was 9.5 inches. Across the rest of the Front Range Foothills, storm totals ranged from 12 to 30 inches. Storm totals along the I-25 corridor ranged from 9 to 18 inches. The eastern plains picked anywhere from 4 to 13 inches of snowfall.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Denver/Boulder, CO wrote its last area forecast discussion before the first event at Nov 25, 10:03 AM MST, 2 hours 57 minutes earlier.
Area Forecast Discussion National Weather Service Denver/Boulder CO 1003 AM MST Mon Nov 25 2019 .UPDATE... Issued at 952 AM MST Mon Nov 25 2019 Increasing stratus and light snow is starting to fill in across portions of the northern mountains ahead of the incoming trough. Overall, the system is still on track to impact the northern plains after noontime with coverage extending south into Boulder county between 3 and 4 pm. Areas east into Denver metro and along I-25 will see impacts between 4 and 5 pm with some rain ahead of the snow that will start in earnest after 8 pm this evening. changeover to snow for the foothills will be sooner during the late afternoon to early evening hours. Snow intensity will increase in the overnight hours with up to 2 inches per hour possible along the northern foothills to include Fort Collins and Greeley and then south into Boulder. Further east over downtown Denver and into DIA rates will be in the 1 to 1.5 inch per hour after 9 pm and into the early morning hours. Timing has not changed to much from previous forecasts with these updates. What has changed slightly are amounts for some areas as models continue to come in and more hires short-term models come into play. Overall forcing mechanisms and cold air damming set-up remains the same but have dropped QPF and snow ratio for areas east of I-25 and south of I-76. This has brought snow totals for central Denver and DIA down a few inches. Will continue to expect the range of snow values possible in the 8 to 12 inch range just given the variability of forcing and band set-up with this scenario. Have also decreased amounts slightly over portions of SE Denver given a period of possible dry-slotting between 6 and 12z that could impact amounts during this time. I expect this to be minimal as winds do turn more northeasterly and help to increase upslope after 09z. Other than the changes mentioned above, everything else is on track. Impacts remain high and area residents are urged to take precautions and adjust travel plans. && .SHORT TERM...(Today and tonight) Issued at 524 AM MST Mon Nov 25 2019 Models remain in reasonable agreement with the amplifying shortwave moving across Colorado tonight and Tuesday. The mass fields are very similar but there are minor differences on timing and a moderate spread in the snow amounts. The operational ECMWF is now a bit of an outlier with a slower but not quite as strong system. It still produces a lot of snow. The GFS and NAM continue to trend a little slower and stronger, and the HRRR looks in line with them as well, so we'll nudge the forecast in that direction. The biggest change with this is that these models hold the snow band north of Denver across the Fort Collins/Greeley/Longmont areas longer this evening with ESE low level winds as a barrier jet starts to develop right along the mountains. As a result, that area really get hit hard starting sometime this evening through much of the night. The more easterly wind component pummels the Larimer and Boulder county foothills, and the barrier jet helps spread that heavy snow eastward into the cities. We'll play this up a bit more, showing 14-18 inches of snow in those cities and up over two feet in the foothills west of Ft Collins. This is still a compromise as the NAM and GFS both show 15-25 inches out onto the plains in this area. For Denver, the main change is to slow down the timing of the snow a bit. The slower models don't really get things going in Denver until the middle of the night, but the slower motion does mean a heftier period of upslope snow under the jet-related band with a barrier jet Tuesday morning, so Denver and the nearby foothills should get pounded for a while late tonight and at least through mid morning Tuesday. The slower motion results in slightly higher totals in most areas. Also a bit more wind late tonight, but the main difference on that is Tuesday. We made some timing adjustments to the warnings and advisories in line with the above thinking. .LONG TERM...(Tuesday through Sunday) Issued at 524 AM MST Mon Nov 25 2019 Models have an upper low circulation over the western half of Colorado at 12Z Tuesday morning. By 18Z, the upper low is centered over southeast Colorado on most of the models. Short wave upper ridging moves late Tuesday into Wednesday morning. Increasing southwesterly IFR by flow aloft moves in for the rest of Wednesday and Wednesday night. There is a jet maximum over Colorado Wednesday afternoon and night...with speeds ranging from 130-170 knots at 250 MB. There still strong upward vertical motion progged for the CWA Tuesday morning. Decent subsidence is in place Tuesday afternoon and night. By Wednesday morning through the night, upward motion is back over Colorado in advance of the next system. There is brisk north-northeasterly low level upslope flow over the CWA much of Tuesday. The progged wind speeds over the eastern half of the plains are getting close to Blizzard Warning criteria. Will make sure we have blowing snow mentioned in the appropriate areas. By Tuesday evening, the low level winds are decreasing and northwesterly. Overnight, the western 3/4ths of the CWA have weak drainage wind fields in place. South- southeasterlies prevail on Wednesday, with more normal looking drainage patterns Wednesday night. There is pretty deep moisture progged for much of Tuesday. Moisture decreases significantly Tuesday evening and night. There is some mid and upper level cloudiness indicated on model cross sections for Wednesday and Wednesday night. Late Wednesday night, there is an increase in moisture over the eastern CWA, including over the low levels. The QPF fields still show healthy amounts of snowfall from 12Z-18Z Tuesday morning. There are some minor amounts Tuesday afternoon, even a tad to linger into Tuesday evening over the eastern CWA and the mountains. As the trends in the models are to continue to slow the system down a bit, will keep the clouds and snow going longer through Tuesday into the early evening. Will up the snowfall amounts a bit accordingly. Highlights are on track. For temperatures, Tuesday's highs are 6-10 C cooler than today's readings. Wednesday's highs are close to Tuesday's highs. For the later days, Thursday through Sunday, models have the strong southwesterly flow aloft continuing on Thursday and Thursday night. The next upper trough is over the Great Basin on Friday. It moves eastward across the CWA Friday night into Saturday. A weak closed circulation in the trough moves eastward north of the CWA through that time but strengthens. Strong northwesterly flow aloft is over the CWA Saturday night with strong zonal flow in place Sunday. Moisture increases over the CWA starting Thursday evening. Then there is moisture around through Saturday night. Mainly scattered pops are in the grids now for the weekend trough. At this time, the weekend trough doesn't look as significant as the current storm does. Temperatures never climb to seasonal normals for the CWA Tuesday through Sunday. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon) Issued at 952 AM MST Mon Nov 25 2019 VFR conditions will give way to IFR in snow in the Denver area between 01z and 04z, with LIFR conditions prevailing by 06z as snow becomes heavy. Accumulations of 4-8 inches are expected at KDEN/KAPA by 12z Tuesday, with storm totals of 8 to 12 inches by the time the snow ends Tuesday late afternoon. Even heavier snow is possible at KBJC. After the snow ends, drifting snow may continue to be a problem through late Tuesday afternoon, then the winds will diminish. East winds will increase this afternoon, with gusts of 20-25 knots. The winds will stay with a more easterly component into the evening, then become northeast with gusts to 30 knots and eventually north early Tuesday . && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning from 11 PM this evening to 5 PM MST Tuesday for COZ046-048>051. Winter Storm Warning from 3 PM this afternoon to 2 PM MST Tuesday for COZ033-035. Winter Storm Warning from 5 PM this afternoon to 5 PM MST Tuesday for COZ034-036. Winter Weather Advisory from 5 PM this afternoon to 11 AM MST Tuesday for COZ030-032-037. Winter Weather Advisory from 1 PM this afternoon to 2 PM MST Tuesday for COZ031. Winter Storm Warning from 8 PM this evening to 5 PM MST Tuesday for COZ039>045. Winter Storm Warning from 5 PM this afternoon to 2 PM MST Tuesday for COZ038. Winter Weather Advisory from 11 PM this evening to 5 PM MST Tuesday for COZ047. && UPDATE...Bowen SHORT TERM...Gimmestad LONG TERM...RJK AVIATION...Bowen
Hazardous Weather Outlook National Weather Service Denver/Boulder CO 1101 AM MST Mon Nov 25 2019 COZ030>051-261815- Jackson County Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- Grand and Summit Counties Below 9000 Feet- South and East Jackson/Larimer/North and Northeast Grand/ Northwest Boulder Counties Above 9000 Feet- South and Southeast Grand/West Central and Southwest Boulder/ Gilpin/Clear Creek/Summit/North and West Park Counties Above 9000 Feet-Larimer and Boulder Counties Between 6000 and 9000 Feet- Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- Central and Southeast Park County- Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties- North and Northeast Elbert County Below 6000 Feet/North Lincoln County- Southeast Elbert County Below 6000 Feet/South Lincoln County- Logan County-Washington County-Sedgwick County-Phillips County- 1101 AM MST Mon Nov 25 2019 ...HEAVY SNOW TONIGHT INTO TUESDAY WITH INCREASING WINDS ON THE PLAINS TUESDAY... This hazardous weather outlook is for northeast and north central Colorado. .DAY ONE...Today and Tonight A significant snow storm will occur over the forecast area this afternoon through Tuesday. Snow will develop over the northern mountains by late morning and spread gradually southward. The snow will become heavy in the northern mountains by late afternoon and spread south toward the Interstate 70 mountain corridor and onto the plains around Fort Collins, Loveland, Longmont and Greeley by early evening. The heavy snow will reach the Denver area by late evening, and spread east across the plains overnight. The snow is expected to be very heavy in areas north of Denver during the evening and overnight hours, and this will be moving into Denver and the nearby foothills after midnight. Snow accumulations by sunrise Tuesday are expected to range from 8 to 18 inches in areas north of Denver, with 6 to 12 inches in the higher mountains and from Denver east across the plains. The foothills of Larimer and Boulder counties may have even heavier amounts. Travel will become difficult or impossible in the areas of heavy snow. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday Moderate to heavy snow will continue across the forecast area Tuesday morning, then decrease from west to east through the afternoon, and end early Tuesday evening. Total snowfall amounts will range from 8 to 16 inches across most of the area, with up to 22 inches from Boulder north to Fort Collins and up to 30 inches in the foothills of Larimer and Boulder counties. Strong northerly winds of 15 to 30 mph are expected over the plains later this evening through Tuesday creating blowing snow. Gusts to 40 mph over the eastern part of the plains may create near blizzard conditions Tuesday afternoon. Travel conditions will be difficult to impossible in the warning area Tuesday morning, then improve from west to east later Tuesday afternoon and early evening as the storm moves out. Wednesday looks pretty dry across the forecast area. An unsettled weather pattern is expected Thursday through Saturday with a good chance of snow and temperatures below seasonal normals. .SPOTTER INFORMATION STATEMENT... Snowfall reports from spotters will be appreciated.
The national radar mosaic for the moment the first event began.
12 winter storm, 8 winter weather, 8 blizzard. Local standard time, as filed.
Storm totals included: 13.5 inches, 4 miles southeast of Mount Zirkel, 9 inches, 11 miles south of Buffalo Park and 9 miles south-southeast of Spicer.
Storm totals included: 21 inches, 9 miles southeast of Cameron Pass; 18 inches, 4 miles north-northwest of Longs Peak and 7 miles northwest of Red Feather Lakes; 16.5 inches, 9 miles east of Glendevey and 3 miles southwest of Meeker; 15 inches at Bear Lake; 13.5 inches near Mount Audubon.
Storm totals included: 40.5 inches at Buckhorn Mountain; 35.5 inches, 3 miles south-southeast of Glen Haven; 33 inches, 3 miles north-northeast of Drake; 32 inches, 11 miles southeast of Estes Park and 4 miles east-northeast of Red Feather Lakes; 24.5 inches, 3 miles west of Jamestown; 24 inches, 11 miles west-southwest of Livermore and 6 miles northwest of Lyons; 22 inches near Crisman; 21 inches, 4 miles east-northeast of Nederland; 20.5 inches near Allenspark; 17.5 inches, 7 miles east-northeast of Virginia Dale, 13.5 inches, 3 miles northeast of Aspen Springs; 13 inches near Estes Park; 9 inches, 9 miles west-southwest of Rustic.
Storm totals included: 30 inches near Crescent Village; 27.5 inches near Genesee; 23 inches near Aspen Park; 22.5 inches, 12 miles northwest of Golden and 4 miles southeast of Pinecliffe; 17 inches near Schaffers Crossing; 16 inches at Roxborough Park; 14 inches, 4 miles west-northwest of Conifer; 13.5 inches near Evergreen; 10 inches at Aspen Springs.
Storm totals included: 16 inches in Wellington; 15 inches, 2 miles north of Loveland; 14 inches, 2 miles northwest of Fort Collins; 12 inches in Fort Collins.
Storm totals ranged from 4 to 7 inches.
Storm totals included: 12 inches, 9 miles southeast of Weston Pass; 10.5 inches near Echo Lake, with 4 to 8 inches elsewhere.
Storm totals included: 23 inches in Lyons; 22 inches at the National Weather Service in Boulder and 7 miles south of Lyons; 16 inches, 4 miles west-northwest of Arvada and near Louisville; 14 inches in Broomfield; 13.5 inches, 2 miles west of Westminster; 13 in Longmont; 12.5 inches near Thornton; 12 inches in Lafayette; 11.5 inches in Wheat Ridge, 11 inches in Edgewater, Erie and Northglenn.
The official snowfall measurement at Denver International Airport was 9.5 inches.
Storm totals included: 16.5 inches in east Parker; 16 inches, 5 miles north of Elizabeth; 12 inches near Castle Rock and Elizabeth; with 10 inches in Lone Tree.
Storm totals included 8 inches, 6 miles northwest of Greeley and 6 inches at Firestone.
Storm totals included: 16 inches, 15 miles north of Elizabeth; 11.5 inches, 5 miles east-northeast of Byers; 7 inches, 2 miles west-southwest of Byers.
Storm totals included 7 inches, 21 miles north of New Raymer.
Storm totals included 8 inches in Agate.
Storm totals included: 13 inches, 5.7 miles west of Otis; 6 inches, 6 miles southeast of Anton and 17 miles south-southeast of Woodrow.
Strong wind gusts and light snow produced areas of blowing and drifting snow, along with poor visibility.
Strong wind gusts and light snow produced areas of blowing and drifting snow, along with poor visibility.
Strong wind gusts and light snow produced areas of blowing and drifting snow, along with poor visibility.
Strong wind gusts and light snow produced areas of blowing and drifting snow, along with poor visibility.
Strong wind gusts and light snow produced areas of blowing and drifting snow, along with poor visibility.
Whiteout conditions due to blowing and drifting snow resulted multiple road closures, as well as the closure of schools, state and federal buildings.
Whiteout conditions due to blowing and drifting snow resulted multiple road closures, as well as the closure of schools, state and federal buildings.
Whiteout conditions due to blowing and drifting snow resulted multiple road closures, as well as the closure of schools, state and federal buildings.
Whiteout conditions due to blowing and drifting snow resulted multiple road closures, as well as the closure of schools, state and federal buildings.
Whiteout conditions due to blowing and drifting snow resulted multiple road closures, as well as the closure of schools, state and federal buildings.
Whiteout conditions due to blowing and drifting snow resulted multiple road closures, as well as the closure of schools, state and federal buildings.
Whiteout conditions due to blowing and drifting snow resulted multiple road closures, as well as the closure of schools, state and federal buildings.
Whiteout conditions due to blowing and drifting snow resulted multiple road closures, as well as the closure of schools, state and federal buildings.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2019Every state in 2019This day in weather historyWarnings in Colorado, November 2019
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 863527, 863510, 863511, 863513, 863514, 863530, 863583, 863515, 863516, 863517, 863519, 863521, 865019, 865022, 865280, 863531, 865014, 865015, 865016, 865021, 865257, 865258, 865259, 865260, 865261, 865262, 865263, 865270.