A couple of Pacific cold fronts combined with favorable jet dynamics to produce heavy snowfall across portions of the western mountains. The highest amounts fell in the Tetons and Absarokas, where the Jackson Hole Ski Resort and Blackwater SNOTEL reported 16 inches of new snow respectively.
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The episode as NWS RIW wrote it up.
A couple of Pacific cold fronts combined with favorable jet dynamics to produce heavy snowfall across portions of the western mountains. The highest amounts fell in the Tetons and Absarokas, where the Jackson Hole Ski Resort and Blackwater SNOTEL reported 16 inches of new snow respectively. Heavy snow also fell in Yellowstone Park, where 12 inches of snow was reported at Parker Peak. Meanwhile, a tight pressure gradient and mixing of strong winds aloft to the surface brought high winds to portions of central Wyoming. The strongest winds were in the Green and Rattlesnake Range, where a prolonged period of high wind occurred with a maximum gust of 87 mph.
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 Mar 7, 1:27 PM MST, 8 hours 33 minutes earlier.
Area Forecast Discussion National Weather Service Riverton WY 127 PM MST Tue Mar 7 2017 .SHORT TERM...Tonight Through Friday The relentless, active winter will continue for the foreseeable future, especially across the west where snow will fall much of the short term and beyond. Temperatures do moderate Wednesday into Thursday with some of the valley locations, mainly Star Valley, potentially mixing with rain at times. The Jackson Valley is more of a challenge with some of the guidance keeping it snow the entire period and others mixing it or changing it to rain at times. H7 temps warm to around -4c Thursday afternoon. Those temps are marginal but with potential for significant pcpn falling, I feel it will be snow during the day Thursday. Temps do continue to warm slightly Thursday night to -2.5 to -3c at H7 with temps likely holding fairly steady overnight. Cooler air starts working back in Friday. Tough call with significant pcpn expected. We are planning on issuing a winter storm watch for zones 12 and 13 (Tetons/Jackson Valley) for Thursday through Friday to cover potential/likely heavy snow. Teton time height is fairly impressive Thursday through at least Friday morning. Mountains will of course be all snow with 1 to 2 feet quite possible. Snow is already underway with decent upglide and approaching shortwave which moves through tonight. Winter weather advisory looks good and that will continue. Snow may taper off later Wednesday morning but light snow will continue for most areas not only Wednesday afternoon but into Wednesday night before snow increases quite a bit late Wednesday night or towards sunrise Thursday when snow and wind may become quite significant. Areas east of the divide, will warm up with breezy to wind (to very windy) areas through the period. High wind potential for the Cody Foothills looks possible for tonight with stable upstream layer and wrf cross sections showing some mtn wave potential. Will upgrade to a watch with modest confidence. Feel best bet will be the normal early morning hours Wednesday but some risk through the period so will just upgrade as is. The other challenge is the Canadian front that will likely sag into the nrn zones later Wednesday night into Thursday morning and possibly all the way into nrn Natrona Thursday morning. Temperatures will be considerably colder behind the boundary so we'll have to watch the high temp fcst for Cody, Greybull over to Buffalo and vicinity. Front may sag a little further south Thursday night before retreating on Friday back to the north. Quite 'balmy' ahead of the front with 50s a good bet but 30s to lower 40s at best north. Some light pcpn may overrun this boundary. We'll definitely need to watch the Cody Foothills with energy overrunning the cold dome during this period. .LONG TERM...Friday Night Through Tuesday Medium range forecast models in much better agreement regarding the overall pattern evolution through the weekend into early next week. Prevailing west-northwest flow aloft will bring a series of weather disturbances across the northern portion of the forecast area, the first beginning Friday night. This shortwave will increase the chance of precipitation across Johnson County, the Bighorn Range, and the extreme eastern Big Horn Basin. Have increased precipitation chances in these areas. There should be a noticeable decrease in precipitation behind this feature across the far western part of the state. Weak ridging Saturday ahead of the next shortwave will keep conditions dry Saturday. Snow will begin to increase in the west late Saturday night as the next batch of moisture reaches northwest Wyoming. Cyclonic flow increases across the north and surface high pushes into the Northern Plains. Therefore, expect a cold frontal boundary to wobble back toward the south Sunday night, which would increase the chance of snow across Johnson County. Have adjusted precipitation chances accordingly to reflect the interaction between the shortwave and the boundary. Conditions turn drier after passage of this trough with the exception of lingering snow across the northern mountains. Ridge develops to our west later Monday and Tuesday with drier conditions across much of the area. The far west mountains will again see a chance of light snow, but better moisture surge appears to arrive beyond this forecast period. Windiest days look to be Sunday and Tuesday. Wind corridor will see 20 to 35 mph westerly winds Sunday ahead of the trough. As for Tuesday, lee trough over the plains will allow for similar speeds in the same area, especially Natrona County. Temperatures will be mild through the period with many areas above normal. Cold front over the north early Monday will retreat and temperatures will rise across the central and south. Have adjusted some basins upward slightly as 700 mb temperatures rise Monday and Tuesday. GFS and ECMWF both have +2C by Tuesday, so highs in the 50s will be widespread with some areas reaching the 60s. Lee troughing and the associated wind will only serve to further boost readings, which may end up being too cool as now forecasted. && .AVIATION.../00Z ISSUANCE/ WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES Persistent, moist west-northwest flow will prevail across far western Wyoming Tuesday night into Wednesday morning. KJAC will see IFR/MVFR through this afternoon with IFR this evening as a more robust moisture plume reaches western Wyoming. Best chance for periods of light snow will come later tonight at KPNA and to a lesser extent KBPI. Southerly surface wind 15-25kts will persist at KJAC, while west-northwest wind will diminish around sunset at KBPI and KPNA. Conditions should show some improvement around 12Z/Wed at all terminals, but KJAC likely to remain MVFR through much of the day Wednesday. Other terminals to be VFR after 12Z/Wed. KRKS to be VFR through the forecast period. Westerly 25-35kt wind will decrease at sunset before increasing again to 20-30kts late Wednesday morning. Wednesday afternoon surface winds at KBPI and KPNA will be west-northwest at 10-20kts. EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES Terminals will be VFR through the forecast period, while the main forecast issue remains the gusty wind. KCPR west-southwest wind will decrease slightly to 18G28kts overnight before increasing again 10Z-14Z/Wed. West-northwest wind may not kick-in until 20Z-22Z/Wed at KRIW and KLND. To the north at KCOD, diurnal west wind will create occasional 20G30kts with decreasing nocturnal speeds. Northwest 10-20kt wind will decrease with the setting sun with speeds remaining less than 12kts until perhaps late Wednesday afternoon. && .FIRE WEATHER... Fire Danger low to moderate across the forecast area through the week as continued good existing snow cover or recent wetting precipitation/ground cover combines with continued seasonal to below seasonal temperatures. However, gusty west to southwest winds can be expected to continue across much of the region through the week. Southwest winds will be strong at times and gusty for all locations on today. Smoke dispersion will be fair to very good across most of the forecast area each afternoon through at least Thursday. && .RIW WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 5 PM this afternoon to 5 PM MST Wednesday for WYZ001-012-013-023. Winter Storm Watch from late Wednesday night through Friday afternoon for WYZ012-013. High Wind Warning from 11 PM this evening to 5 AM MST Thursday for WYZ003. && SHORT TERM...Skrbac LONG TERM...CNJ AVIATION...CNJ FIRE WEATHER...Skrbac
Hazardous Weather Outlook National Weather Service Riverton WY 114 PM MST Tue Mar 7 2017 WYZ001>020-022>030-081200- 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- 114 PM MST Tue Mar 7 2017 ...Winter Weather Advisory for Portions of Western Wyoming Tonight Through Wednesday... ...High Wind Warning for the Cody Foothills from later Tonight Through Wednesday Night... ...Winter Storm Watch for the Tetons/Gros Ventres and Jackson Valley early Thursday through Friday afternoon... This Hazardous Weather Outlook is for Western and Central Wyoming. .DAY ONE...Today and Tonight Snow likely in the western mountains and far west valleys, possibly moderate to heavy at times tonight and Wednesday. Very windy conditions will continue across Sweetwater and Natrona counties in addition to the Cody Foothills. .DAYS TWO THROUGH SEVEN...Wednesday through Monday Wednesday...Snow likely in the western mountains and far west valleys, possibly moderate to heavy Tuesday night and Wednesday morning. Windy conditions will continue across Sweetwater and Natrona counties. Thursday and Friday...Significant snow possible across the western mountains, especially Teton County. Windy from South Pass to Casper, as well as the Lander and Cody Foothills. .SPOTTER INFORMATION STATEMENT... Spotters are urged to report any snowfall amounts and wind gusts past 50 mph. Thank you. Team Riverton
The national radar mosaic for the moment the first event began.
3 winter storm, 2 high wind. Local standard time, as filed.
The RAWS at Camp Creek had an extended period of high wind that continued for over 2 days. There were numerous wind gusts of hurricane force including a maximum gust of 87 mph.
The wind sensor along Outer Drive south of Casper recorded several wind gusts past 58 mph including a maximum gust of 68 mph.
Several SNOTEL sites reported over a foot of new snow. The highest amount was 16 inches at the Blackwater SNOTEL.
The SNOTEL site at Parker Peak reported 12 inches of new snow.
The ski patrol at Jackson Hole Ski Resort measured from 12 to 16 inches of new snow.
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, March 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: 681223, 681224, 681221, 681222, 681220.