The combination of a potent upper level disturbance and an ample supply of Pacific moisture brought heavy snow to portions of western Wyoming. The highest amounts fell in the Tetons were 21 inches of new snow was measured at the Jackson Hole Ski Resort.
Every event with a place to put it; 7 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.
The combination of a potent upper level disturbance and an ample supply of Pacific moisture brought heavy snow to portions of western Wyoming. The highest amounts fell in the Tetons were 21 inches of new snow was measured at the Jackson Hole Ski Resort. Over a foot of new snow also fell in portions of the Absarokas, Salt and Wyoming Range and Yellowstone Park. A combination of snow and winds gusting over 60 mph closed South Pass for a time over the Wind River Mountains. In the lower elevations, the heaviest snow fell in the Jackson Valley where a foot of new snow was measured near Wilson. High wind also blew in portions of the Cody foothills where winds topped put at 76 mph near Clark.
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 3, 10:52 AM MST, 1 hour 8 minutes earlier.
Area Forecast Discussion National Weather Service Riverton WY 1052 AM MST Fri Feb 3 2017 .SHORT TERM...Friday through Sunday night With the contrast in conditions...we will split the discussion into West and East of the Divide this morning. Active weather will continue across the area into the weekend. As of now we are in a relative lull with the snow stopped temporarily for the most part in all areas. However, the break will not be long as another in a train of shortwaves with ample Pacific moisture move into western Wyoming. Some snow will return this afternoon. However, at this time it appears that the heaviest snow will hold off until tonight and especially later tonight and Saturday morning as an approaching trough, trough axis and the best dynamics move through the area. Many areas have a good chance to see warning level amounts so we will hoist winter storm watches across much of the area. A few other areas may see advisory level amounts but since snow should wait until this evening to start, we will let the day crew make the final call on that. There is some warmer air moving into the area for Saturday though. The MOS guidance has Jackson climbing to around 40. Right now, the 700 millibar temperatures do not support that however. For now, we have a bit of mix in the valleys Saturday afternoon but confidence on any rain is fairly low at this time. There should be a let up in the snow Saturday evening into Saturday night. However, some light snow will likely continue right into Sunday as another, although weaker shortwave moves through the area. The models do show another break Sunday afternoon into Sunday evening. Yet another system may move back in for later Sunday night. However, there are some intensity and timing issues this far out so we went middle of the road at this time until greater model consensus is reached. East of the Divide... First, as for snow through the weekend, this will not be a concern expect for the mountains. Strong downsloping flow should keep most areas mainly dry. However, like so many times this winter, the concern here will shift from snow to wind. There should not be too much wind this morning. The story this morning will be the cold temperatures with the sky clearing in many areas and some fresh snow cover increasing the albedo across the area. However, with the system approaching from the west the pressure gradient will tighten and mid level winds will increase through the day. Across the Cody Foothills, the models show the 700 millibar winds increasing to 60 to 65 knots tonight into Saturday. With the trough passage helping to increase downward forcing, we will hoist a high wind watch across the area with the main impact near the crossroads of the Universe. There could be more high wind on Sunday as well as another shortwave passes as well. The wind will also increase across the southwestern wind corridor from Rock Springs through Casper. The 700 millibar winds to climb to around 50 knots. However, with the direction more west-northwesterly rather than the favored southwest, most areas should remain below high wind criteria. It will turn quite blustery late today and especially tonight and through much of the weekend. This will also mix the atmosphere and bring a moderation of temperatures with above normal temperatures possible for the areas that mix. And this brings us the next question, will some of the Basins and deeper Valleys be able to mix out. Today, the answer is no and we kept temperatures well below guidance as a result as winds are expected to remain fairly light. The question is for Saturday. The NAM is especially bullish showing a high of 56 in Riverton for Saturday. As for my opinion on this, the NAM appears to be drunk with this, especially given the deep snow cover in many areas. The GFS looks more reasonable with high temperatures but even it looks too warm. As a result, we kept things cool. If it does get warmer, given the recent cold weather most people will be happy. Cooler temperatures will then return for Sunday. However, with the Pacific origin of the air, temperatures will not be too cool. .LONG TERM...Monday through Friday The parade of winter storms will continue on Monday. A quick moving shortwave in a moist westerly flow in combination with some left front dynamics associated with an upper jet Monday/Monday night should result in another good shot of significant snowfall across the west. East of the Divide, a quasi-stationary cold front over central/southern Montana and western south Dakota Monday is expected to shift southwest into the area Monday night/Tuesday. The southwest advancement of this Arctic cold front is being impeded by strong westerly flow aloft, and models are having difficulty on how much of the area east of the Divide will be impacted. Areas west of the Divide will be spared from this cold air. Regardless of location, Monday looks to be dry and windy east of the Divide. However by Monday night and Tuesday some snowfall could occur east, but not on the scale expected over the west Monday and Monday night. 00Z model guidance are progging a brief break in the snowfall over the west Tuesday with main forecast challenge being placement of Arctic cold front east of the Divide. Tuesday night and Wednesday, models show a strong, moist west northwest flow across the area which should bring another round of snowfall to the west. However models are lighter with the snowfall than compared to previous systems leading up to this event. Some of this snowfall could spill east of the Divide Wednesday. A well amplified transitory ridge is expected to move across the area Thursday with mainly dry conditions. The main forecast challenge will be temperatures east of the Divide. Although the Arctic cold front is expected to be north and/or west of the forecast area, there is a chance of trapped basins remaining much cooler than forecast. The endless stream of Pacific storms send another potential storm system into the area Friday, mainly impacting the west. 700mb temperatures over the west are being progged to be -2 to -4C which could translate to some rain in the western valleys. Dry, mild and breezy east of the Divide. .AVIATION.../18Z ISSUANCE/ West of the Divide...KBPI/KJAC/KPNA/KRKS Terminals Scattered light snow in the west through this afternoon with areas of MVFR ceilings. Then the snow will increase during the afternoon with snow continuing through tonight. MVFR to IFR conditions will be common by 03Z in the west with mountains obscured. The snow and ifr ceilings will spread across southern WY including the KRKS airport where snow is expected around 04z continuing through tonight and Saturday morning. Areas of low level wind shear will be found over and near the east slopes of the Teton, Gros Ventre, Wyoming and Salt River mountains through the period. East of the Divide...KCOD/KCPR/KLND/KRIW/KWRL Terminals VFR conditions are to prevail through tonight. Areas of low clouds or fog will occur through 21Z with MVFR conditions in the lower areas of the Big Horn basin and Wind River basin. The wind will be increasing at KCPR airport this afternoon and windy conditions will occur tonight. Areas of low level wind shear will be found over and near the east slopes of the Absaroka and Wind River mountains through the period. .FIRE WEATHER... Periods of snow will continue across western Wyoming, especially northwestern Wyoming through the weekend. Meanwhile, East of the Divide mainly dry conditions are expected with the exception of the mountains. There will be warmer temperatures today with the warmest day on Saturday. Windy conditions are likely Friday night and into the weekend in the favored areas like in the Lee of the Absarokas and from the Red Desert through Natrona County. && .RIW WATCHES/WARNINGS/ADVISORIES... Winter Storm Watch from 5 PM MST this afternoon through Saturday evening for WYZ001-002-012>015-023-024. High Wind Watch from 8 PM MST this evening through Saturday afternoon for WYZ003. && SHORT TERM...Hattings LONG TERM...WM AVIATION...C.Baker FIRE WEATHER...Hattings
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 308 AM MST FRI FEB 3 2017 WYZ001>020-022>030-041300- 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- 308 AM MST FRI FEB 3 2017 ...WINTER STORM WATCHES IN EFFECT FOR MUCH OF THE WEST TONIGHT INTO SATURDAY NIGHT... ...HIGH WIND WATCH FOR THE CODY FOOTHILLS TONIGHT AND SATURDAY... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT MODERATE TO HEAVY SNOW RETURNING TO THE WEST LATER TODAY AND TONIGHT. PLEASE SEE WINTER WEATHER PRODUCTS AND FORECASTS FOR DETAILS. HIGH WIND POSSIBLE IN THE LEE OF THE ABSAROKAS TONIGHT. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY SATURDAY AND SUNDAY...MORE SNOW LIKELY IN THE WEST. STRONG WINDS POSSIBLE IN THE LEE OF THE ABSAROKAS AND FROM THE RED DESERT THROUGH CASPER. MONDAY AND MONDAY NIGHT...SIGNIFICANT SNOW LIKELY ACROSS THE WEST. WINDY TO STRONG WIND POSSIBLE ACROSS THE WIND CORRIDOR FROM ROCK SPRINGS TO CASPER, MOUNTAINS AND SOME ADJACENT FOOTHILLS EAST OF THE DIVIDE. TUESDAY NIGHT AND WEDNESDAY...LIGHT TO MODERATE SNOW RETURNS TO WESTERN WYOMING. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT SNOWFALL AMOUNTS. THANK YOU.
The national radar mosaic for the moment the first event began.
6 winter storm, 1 high wind. Local standard time, as filed.
Heavy snow fell in portions of Yellowstone Park. The highest amount recorded was 14 inches at the East Entrance to the park.
Heavy snow fell in portions of the Absarokas. The highest amount recorded was 14 inches at the Beartooth Lake SNOTEL.
At the Jackson Hole Ski resort, 21 inches of new snow was measured.
Heavy snow fell in portions of Jackson Valley. Some of the highest amounts included 12 inches near Wilson and 10 inches near Teton Village.
A combination of snow, blowing snow and strong wind caused the closure of Wyoming Route 28 over South Pass for several hours.
A combination of snow, blowing snow and strong wind caused the closure of Wyoming Route 28 over South Pass for several hours.
The wind sensor west of Clark had several wind gusts past 58 mph, including a maximum of 76 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2017Every state in 2017This day in weather historyWarnings in Wyoming, February 2017
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: 674870, 674871, 674975, 674976, 674977, 674978, 674979.