A strong pressure gradient developed ahead of an advancing winter storm and brought high wind to portions of the favored southwest flow locations. The strongest wind occurred in the Wind River Range where wind gusts as high as 98 mph were observed near Red Canyon.
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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 strong pressure gradient developed ahead of an advancing winter storm and brought high wind to portions of the favored southwest flow locations. The strongest wind occurred in the Wind River Range where wind gusts as high as 98 mph were observed near Red Canyon. Strong wind occurred around Casper as well, with a maximum wind gust of 65 mph along Wyoming Boulevard on the south side of Casper.
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 Apr 1, 10:38 AM MST, 12 minutes earlier.
Area Forecast Discussion National Weather Service Riverton WY 1138 AM MDT Sat Apr 1 2023 .DISCUSSION...Today through Friday Issued at 308 AM MDT Sat Apr 1 2023 Even though we are well outside of the window for 6 more weeks of winter, we just can't catch a break. I wish I could say, "and now for something completely different", but alas here we are preparing for another winter storm. No, this is not an April Fool's joke. A shortwave ridge will build over the Cowboy State today, as a trough begins to move onshore and dig over the PACNW. 700mb winds of 40-50 kt from the southwest will increase through the morning over southern portions of the CWA to Natrona County. The sfc pressure gradient will also tighten in response to this approaching system. Gusts over 60 mph will be likely at Red Canyon and the east slopes of the Wind River Mountains and Outer Drive in Casper. Clark, north of Cody, could also be impacted. West to southwest winds, with gusts of 25 to 45 mph, will be widespread across the forecast area this afternoon. These winds will help mix out the valleys and basins. Temperatures east of the Divide will be in the mid 40s to mid 50s, as a result. This should help in continuing to melt the snow that remains on the ground and hopefully melt any ice in the creeks and rivers. Chances for snow over northwestern portions will continue to increase this morning, becoming likely by sunrise. Light to moderate snow will then occur through the rest of the morning. Periods of heavy snow will be possible this afternoon and evening, before becoming light again after midnight. Forecasted snowfall totals remain on track, with warning amounts over the Tetons, southern Yellowstone and southwestern portions of the Absarokas. Advisory amounts will occur elsewhere over the western mountains and the Jackson Valley. The Star Valley is expected to only receive 1 to 2 inches. The associated cold front from this system will move through the area tonight, turning winds more northwesterly in its wake. The high winds over central portions today will begin to subside a bit this evening behind the front. Do not expect wind gusts of 60+ mph to continue into Sunday morning as a result, so will shorten the High Wind Warnings to 11 PM. With that said, gusty winds will continue into Sunday especially over northern portions. Additionally, snow will become light by Sunday morning. A more zonal flow pattern will be in place over the region Sunday. Light snow will continue over western portions through the day, as Pacific moisture streams through the flow. Additional snowfall amounts of 1 to 3 inches will occur over the Tetons/Gros Ventres and portions of Yellowstone over to Togwotee Pass, with 3 to 6 inches expected over the Salt/Wyoming Ranges. A trough will begin to dig over the PACNW late Sunday afternoon into Sunday night, as an upper level low slides southward along the British Columbia coast. The Pacific moisture will get pushed over southern portions Sunday night, as a result of this developing storm. This will set up an overrunning scenario across central and southern portions of the CWA, as winds turn east-northeasterly east of the Divide. The ECMWF Extreme Forecast Index (EFI) and Shift of Tails (SOT) continue to suggest a high impact event from southern Lincoln and Sweetwater counties to Natrona County from Sunday evening to late Monday afternoon. Despite this, all areas across the forecast area will see accumulating snow. Have opted to issue Winter Storm Watches across central and southern portions as a result. Light snow will continue across the area Tuesday, before gradually ending Tuesday night as the storm exits over the Plains. Needless to say, temperatures will remain well below normal Monday through Wednesday. Apart from possible lingering light snow showers Wednesday, quiet weather conditions are expected through the rest of the week. && .AVIATION...(For the 18Z TAFS through 18Z Sunday) Issued at 1129 AM MDT Sat Apr 1 2023 West of the Divide...KBPI/KJAC/KPNA/KRKS Terminals Terminals will see mainly VFR conditions throughout the TAF period with KJAC being the only exception. KJAC will see periods of MVFR/IFR conditions for the remainder of the period. Prevailing light snow will remain in the area with a moderate snow developing by 20Z Saturday. At this time winds increase as well with a SW gust of 25 to 35 knots possible. By 06Z Sunday snow intensity will decrease with mainly MVFR conditions prevailing. By 13Z Sunday winds lower slightly with gusts around 20 knots. Also at this time another round of moderate snow looks to develop and remain into the end of the TAF period. KBPI, KPNA, and KRKS will see gusty winds through the entire period with gusts ranging from 20 to 35 knots at times. KRKS may see light snow develop around 08Z Sunday. By 11Z Sunday snow showers linger in the area into the end of the period. Mountain obscuration will occur for western mountains throughout the TAF period. East of the Divide...KCOD/KCPR/KLND/KRIW/KWRL Terminals All terminals see prevailing VFR through the TAF period except for KCOD. KCOD will see a period of light snow develop around 01Z Sunday. A moderate band of snow looks to develop around 03Z into 06Z, afterwards lingering snow showers remain until 14Z. All terminals will see strong gusts continue or develop shortly after 18Z Saturday. KLND, KCPR, and KCOD will see the strongest gusts ranging from 35 to 45 knots with gusts around 50 knots possible. KRIW and KWRL still see strong gusts between 20 and 35 knots. Mountain obscuration will during the first half of the TAF 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 310 AM MDT Sat Apr 1 2023 Snow showers will return to western WY this morning, with significant snowfall by this afternoon. Snow will become light by Sunday morning and continue into Sunday night. Otherwise, most of central, northern, and southern areas will remain dry on Saturday. Wind will be a bigger concern over these areas today, with gusts over 40 mph occurring through the evening. Gusts over 60 mph are possible from South Pass through Natrona County, as well as along the northern portions of the Cody Foothills today. These winds will subside tonight, with gusts over 40 mph continuing across northern portions Sunday. A major winter storm will impact the forecast area Sunday night into Tuesday, with heavy snow occurring Sunday night into Monday night. && .RIW WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until 6 AM MDT Sunday for WYZ001-012. Winter Weather Advisory until 6 AM MDT Sunday for WYZ002-013-014- 024. Winter Storm Watch from Sunday evening through Tuesday afternoon for WYZ014-015-019-026>030. High Wind Warning until 11 PM MDT this evening for WYZ015- 018>020. Winter Storm Watch from Monday morning through Tuesday afternoon for WYZ017-018-020-022. && DISCUSSION...LaVoie AVIATION...Dziewaltowski FIRE WEATHER...LaVoie/Myers
Hazardous Weather Outlook National Weather Service Riverton WY 328 AM MDT Sat Apr 1 2023 WYZ001>020-022>030-021330- 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- 328 AM MDT Sat Apr 1 2023 ...Multiple Winter Weather highlights Advisories in effect... ...High Wind Warnings in effect for portions of central Wyoming today through tonight... This Hazardous Weather Outlook is for Western and Central Wyoming. .DAY ONE...Today and Tonight. Light to moderate snow across the west. Strong to high winds across portions of central Wyoming, mainly in sections of southern Fremont County and Natrona County. Please see the High Wind Warning and the other winter weather highlights for additional details. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Sunday...Light snow continuing across the west. Monday and Tuesday...Increasing snow across southern portions Sunday night, spreading into central portions early Monday morning. Moderate to heavy snow is possible in these areas through Monday night. Light to moderate snow expected elsewhere. Unseasonably cold. Wednesday...High temperatures 20 to 30 degrees below normal. .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.
2 high wind. Local standard time, as filed.
Wind gusts as high as 65 mph were reported around Casper.
Along Highway 28 in Red Canyon, maximum wind gusts of 98 mph were recorded with hurrricane force wind gusts for several hours.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2023Every state in 2023This day in weather historyWarnings in Wyoming, April 2023
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: 1096768, 1096767.