A Pacific cold front moved into western Wyoming and brought heavy snow to some areas. The heaviest snow fell in the Tetons where there were widespread reports of over 18 inches of new snow with a maximum of 28 inches at Jackson Hole Ski Resort.
Every event with a place to put it; 4 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 RIW wrote it up.
A Pacific cold front moved into western Wyoming and brought heavy snow to some areas. The heaviest snow fell in the Tetons where there were widespread reports of over 18 inches of new snow with a maximum of 28 inches at Jackson Hole Ski Resort. Other notable amounts included 15 inches at Alpine, Wyoming, in Lincoln County and 8 inches in Teton Village, Wyoming.
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 Riverton, WY wrote its last area forecast discussion before the first event at Feb 15, 2:44 PM MST, 16 minutes earlier.
Area Forecast Discussion National Weather Service Riverton WY 244 PM MST Sat Feb 15 2020 .SHORT TERM...(This evening through Sunday night) Issued at 245 PM MST Sat Feb 15 2020 Water vapor imagery shows a plume of Pacific moisture heading towards Wyoming. The atmosphere will continue to moisten up for the remainder of the afternoon and evening. Models are consistent in showing decent isentropic upglide developing this evening. As this occurs the coverage and intensity of snow will increase across western wyoming. A moist, orographic westerly flow will continue through much of Sunday with steady snow, enhanced at times by perturbations in the flow ahead of the main trough/sfc cold front. Some snow could impact Sweetwater County late tonight, before better chances of snow return over Sweetwater County Sunday afternoon and evening with the main cold front. Areas east of the Divide will be mainly dry through much of the day Sunday. However, in wake of the cold front late Sunday/Sunday night, some accumulating snow is expected to occur east of the Divide with models showing a mid-level convergence area sliding south Sunday night. The Bighorn Mountains, Johnson County and even possibly Natrona County could approach low-end advisory amounts of snowfall. However overall confidence right now is low for snow amounts east of the Divide. No changes have been made to the ongoing warning/advisory out west, except very minor tweaks to snowfall. .LONG TERM...(Monday through Saturday) Issued at 245 PM MST Sat Feb 15 2020 Monday will feature some lingering light snow across the area between the continued moist but weakening northwest flow, and a weak upstream shortwave within the northwest flow. There will be a period of more significant snow that will produce sub advisory amounts for the west Monday afternoon ahead of this trough where negative lifted indices will occur briefly. The relatively weak confluent flow will discourage any large snowfall amounts with this troughpa. Then on Tuesday, some light snowfall in the northern portion of the CWA will break out ahead of a backdoor Canadian cold front that will mainly just graze Johnson County Tuesday evening. The trough associated with this front will produced a bit more enhanced snow in the west Tuesday, but again, not very significant. 700Mb temps will become too cold for significant dendritic growth. Temperatures will recover fairly quickly in Johnson County with highs near 40 by Thursday. Otherwise, cold temperatures will linger in the basins for much of the latter portion of the week with a lack of mixing due those areas due to the ridge building into the area from the west. Expect warming temperatures along the southern wind corridor where better mixing will occur. For the first time in a while, the CWA will be precip free Wednesday through Saturday with the aforementioned high pressure and weak steering flow. The Euro puts us back under a fast westerly flow Friday and Saturday with the arrival of another trough, and the Canadian puts us under the faster flow by Saturday. The GFS has us under a weak flow for the entire duration, so for now we will keep conditions dry along with lighter winds. && .AVIATION...(For the 00Z TAFS through 00Z Monday) Issued at 245 PM MST Sat Feb 15 2020 East of the Divide...KCOD/KCPR/KLND/KRIW/KWRL Terminals VFR conditions should prevail through at least 18Z Sunday. Gusty winds will continue at KCPR and KRKS. Then after 18Z Sunday, some snow showers will spill over the Divide from the west into northern Wyoming for LCL MVFR conditions. West of the Divide...KBPI/KJAC/KPNA/KRKS Terminals Another storm system is impacting western Wyoming. Widespread light snow is breaking out over the far west mountains and valleys. Expect continued deteriorating conditions at KJAC. Expect persistent IFR/MVFR conditions tonight and Sunday in the far west and at KJAC through this evening. At KBPI and KPNA, some snow is possible after 07Z Sunday with MVFR to possible IFR conditions through 00Z Sunday. Expect mtn obscn for much of the period. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on icing and turbulence forecasts. && .FIRE WEATHER... Issued AT 245 PM MST Sat Feb 15 2020 Widespread snow will occur over western Wyoming tonight and Sunday. A cold front will push across the area late Sunday into Sunday night. As this occurs, some accumulating snow will begin to impact areas east of the Divide. Smoke dispersal will generally be poor Sunday and Monday. && .RIW WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 8 PM this evening to 11 PM MST Sunday for WYZ001-002-014-025-027. Winter Storm Warning from 8 PM this evening to 11 PM MST Sunday for WYZ012-013-023-024. && SHORT TERM...Murrell LONG TERM...Lipson AVIATION...Lipson FIRE WEATHER...Murrell
Hazardous Weather Outlook National Weather Service Riverton WY 351 AM MST Sat Feb 15 2020 WYZ001>020-022>030-161200- Yellowstone National Park-Absaroka Mountains-Cody Foothills- North Big Horn Basin-Southwest Big Horn Basin- Southeast Big Horn Basin-Owl Creek and Bridger Mountains- Bighorn Mountains West-Bighorn Mountains Southeast- Northeast Johnson County-Southeast Johnson County- Teton and Gros Ventre Mountains-Jackson Hole- Wind River Mountains West-Wind River Mountains East- Upper Wind River Basin-Wind River Basin-Lander Foothills- Green Mountains and Rattlesnake Range- Natrona County Lower Elevations-Casper Mountain-Star Valley- Salt River and Wyoming Ranges-Upper Green River Basin Foothills- Upper Green River Basin-South Lincoln County- Rock Springs and Green River-Flaming Gorge-East Sweetwater County- 351 AM MST Sat Feb 15 2020 ...A variety of Winter Weather Highlights are in effect tonight through Sunday evening for Western Wyoming... This Hazardous Weather Outlook is for Western and Central Wyoming. .DAY ONE...Today and Tonight. Mainly light snow will occur in the Western Wyoming mountains and far west valleys today. The snow will increase in coverage and intensity tonight. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Sunday and Sunday night...Significant snow is likely across the west. Some accumulating snow is possible over the north and east Sunday night and Monday. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions, according to standard operating procedures.
The national radar mosaic for the moment the first event began.
4 winter storm. Local standard time, as filed.
Heavy snow fell in the Tetons. The highest amount was 28 inches at the Jackson Hole, Wyoming Ski Resort. Some other notable amounts included 18 inches at Grand Targhee, Wyoming resort and 14 inches at Togwotee Pass.
Heavy snow fell in portions of the Jackson Valley. The heaviest was 8 inches at Teton Village, Wyoming. Amounts dropped further south with around 3 inches in the town of Jackson, Wyoming.
Heavy snow fell in northern portions of the Jackson Valley. The heaviest was at Alpine, Wyoming, where 15 inches of snow fell. Amounts dropped further south with 4 inches at Afton, Wyoming.
Heavy snow fell in portions of the Salt and Wyoming Range. The heaviest was at Blind Bull Summit where 15 inches of snow fell.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2020Every state in 2020This day in weather historyWarnings in Wyoming, February 2020
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: 878245, 878246, 878248, 878249.