A Pacific system moved into Wyoming and brought heavy snow to portions of the state. The storm was a fairly warm system so snow amounts were fairly elevation dependent.
Every event with a place to put it; 5 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 system moved into Wyoming and brought heavy snow to portions of the state. The storm was a fairly warm system so snow amounts were fairly elevation dependent. Over a foot of snow fell in portions of the Teton, Salt and Wyoming and eastern Wind River Ranges. The maximum amount of new snow was 21 inches at the Grand Targhee Ski resort. The Star Valley saw locally heavy snow, with a foot of new snow near Turnerville. Favorable upslope flow brought heavy snow around Lander as well, with amounts ranging from 5 to 11 inches, with the highest amounts in the foothills of the Wind River Range.
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, 3:55 AM MST, 5 minutes earlier. Its key messages:
Area Forecast Discussion National Weather Service Riverton WY 355 AM MST Sat Feb 3 2024 .KEY MESSAGES... - Snow/rain showers will gradually spread east becoming widespread by Saturday morning. Some areas may see rain or a rain/snow mix to start, with a transition to all snow by Saturday night. - Travel impacts will be most notable over the mountain passes. Heavy, wet, and slushy roads are expected for lower elevations. - Precipitation tapers off Sunday, with a brief lull before the next system moves into western WY by Monday morning. - More chances for widespread precipitation through much of next week, as an active weather pattern continues over the region. && .DISCUSSION... Issued at 123 AM MST Sat Feb 3 2024 An active weather pattern has begun across much of the western CONUS. The first of a series of Pacific moisture fueled systems is currently impacting the Cowboy State. Snow and rain showers are gradually spreading eastward this morning. This is apart of a large negatively tilted trough that is digging over the central CONUS. A potent upper level low will develop during the day Saturday. This low will remain well to the south of WY but will still be capable of funneling moisture over the region. There are a few difficult forecast challenges associated with this system. The first is QPF which has been a rollercoaster ride of up and down trends over the past few days. Currently QPF values have drastically increased over the Wind River Basin as models indicate a mesoscale low developing Saturday morning. This low will help create a period of favorable upsloping, which is likely the reason for such a large jump in QPF values. Elsewhere QPF values have had little to no changes. The other crucial component of the forecast is temperatures, as many places will be flirting with freezing throughout the duration of the system. Temperatures will greatly dictate impacts as cooler temperatures will mean less mixing, especially for those east of the Divide. Western WY has not seem much of a change in the forecast. Snow rates are still expected to increase early Saturday morning, along with higher snow ratios as temperatures cool. The heaviest snowfall is likely to occur during the day Saturday before tapering off Sunday morning. Snowfall accumulations are not very impressive, with the highest amounts near a foot in the higher elevations of the Tetons and Salt River Ranges. Lower elevation valleys are not going to see much, as amounts will range from 1 to 4 inches with higher amounts across Star Valley. East of the Divide, snow and rain will be widespread by the mid to late morning, with a higher chance (60 to 80%) for rain the closer you are to Natrona and Johnson Counties. Most of the Wind River Basin likely (50 to 70%) remains cold enough to see a heavy wet snow. Due to warm surface temperatures and the wet nature of the snow, accumulation is expected to remain on the lighter side during the day. The best chance for accumulation will come Saturday night into Sunday morning, as temperatures will drop and precipitation rates increase. Even with the recent increase in QPF for central basins, impacts are likely to remain minimal. Overall, temperatures will be the crucial factor, as any slight deviation can greatly impact snow accumulations. One thing to keep in mind is that heavier precipitation can aid in cooling the atmosphere. This is something to keep in mind for this morning from 5 AM to 11 AM as this looks to be a period of heavy precipitation across the Wind River Basin. There is a possibility that this heavy precipitation may be enough to keep the atmosphere cool through the remainder of the day. This will be something to monitor through the duration of the event, as temperature forecast confidence is low and looks to be very finicky. Winds increase over southwestern WY during the day today, especially Sweetwater County, where gusts of 30 to 45 mph are possible at times. Winds will shift over the Wind corridor for Sunday into Monday as pressure gradients tighten with the nearing of our next weather system. Gusts will be the strongest on Monday, over parts of Natrona and Johnson Counties, with gusts of 30 to 45 mph. Total snowfall amounts will differ greatly across the state, mainly depending on elevation. Western mountains will see the most accumulation, with amounts of 6 to 10 inches and 12 to 16 inches possible for the higher peaks of the Tetons, Salt, and Wyoming Mountains. For this reason Winter Weather Advisories remain in place across high elevations, with no upgrades to warnings expected at this time. Winter Weather Advisories will remain in place for the higher elevations east of the Divide, such as the Bighorn Mountains and Casper Mountain. Even though the recent forecast has lowered amounts to near or even below criteria impacts will be enough to keep these advisories in place. Lower elevations across much of the state will see amounts ranging from 2 to 4 inches. The Wind River Basin and eastern Sweetwater County have had snowfall amounts increased. Highlights are not likely to be issued at this time due to warm surface temperatures and the heavy wet nature of any snow, which will keep accumulations compact and slushy. Precipitation will gradually come to an end Sunday, with showers lingering into the late afternoon. A brief lull in precipitation looks to occur Sunday night into early Monday morning. The next Atmospheric River event looks to impact western WY by Monday morning and continue through the first half of the week. Early indications show the possibility of another system impacting the state by midweek, bringing widespread precipitation. Overall, the first week of February is looking quite eventful, with numerous chances for precipitation in the near future. && .AVIATION /12Z TAFS THROUGH 12Z SUNDAY/... Issued at 341 AM MST Sat Feb 3 2024 West of the Divide...KBPI/KJAC/KPNA/KRKS Terminals Ongoing light snow at all TAF sites with MVFR ceilings and visibility. This will be mainly on with some off throughout much of the period before snow chances diminish after 00-04Z carrying VCSH after that point (20-30%). Some gusty northwest winds at all but JAC with gusts up to 25kts throughout this period of snow on station. Winds diminish after 00-04Z as the gradient weakens with the upper trough pushing east into Sunday. Otherwise, improved visibilities but still MVFR ceilings through the end of the period as per LAMP and BUFKIT data (50-70%). East of the Divide...KCOD/KCPR/KLND/KRIW/KWRL Terminals Showers in the vicinity of RIW and LND with mixed precipitation on station after about 15Z. Some patchy fog near CPR with MVFR visibility and IFR vertical visibility as well. COD will see snow on station after 14Z with CPR after 22Z and WRL after 00Z. RIW and LND will see a complete changeover to snow with cooling temperatures after 06Z through the end of the period. MVFR ceilings and visibility expected at all TAF sites (80-90%) with possible IFR as well but of less confidence (30-40%). No improvements east of the Divide for this period nor the next TAF cycle, occurring later in the day Sunday. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on icing and turbulence forecasts. && .RIW WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 11 AM MST Sunday for WYZ001-002- 012-014-015-019-024. Winter Weather Advisory until 6 PM MST Sunday for WYZ008-009. Winter Weather Advisory from 11 AM this morning to 5 PM MST Sunday for WYZ022. && DISCUSSION...Dziewaltowski AVIATION...Lowe
Hazardous Weather Outlook National Weather Service Riverton WY 207 AM MST Sat Feb 3 2024 WYZ001>020-022>030-041315- Yellowstone National Park-Absaroka Mountains-Cody Foothills- North Bighorn Basin-Southwest Bighorn Basin-Southeast Bighorn 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- 207 AM MST Sat Feb 3 2024 This Hazardous Weather Outlook is for Western and Central Wyoming. .DAY ONE...Today and tonight. Precipitation will gradually spread east throughout the day today with rain/snow mix possible to start for low elevation areas. Accumulations for low elevations will be hindered by warm surface temperatures and wet heavy snow, creating slushy surfaces. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Precipitation will taper off Sunday with a brief lull until Monday morning. Another system looks to bring more snow to western Wyoming for the start of the week. A wet weather pattern will bring numerous chances for precipitation across the state throughout the week. .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.
5 winter storm. Local standard time, as filed.
Locally heavy snow fell in the Tetons, with a maximum amount of 21 inches at the Grand Targhee ski resort.
Heavy snow fell along the east slopes of the Wind River Range, with a maximum of 18 inches at the Hobbs Park SNOTEL site.
Snowfall amounts around the Lander Foothills generally ranged from 5 to 11 inches, with the highest amounts closer to the Wind River Range.
Up to 19 inches of new snow fell in the Salt and Wyoming Range.
Heavy snow fell in portions of the Star Valley, with a maximum amount of 12 inches near Turnerville.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2024Every state in 2024This day in weather historyWarnings in Wyoming, February 2024
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: 1162623, 1162626, 1162627, 1162624, 1162625.