A combination of a strong pressure gradient and strong low level winds mixing to the surface brought high winds to wind prone areas of northern and central Wyoming. The strongest winds occurred in the vicinity of Clark where gusts as high as 93 mph were recorded.
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The episode as NWS RIW wrote it up.
A combination of a strong pressure gradient and strong low level winds mixing to the surface brought high winds to wind prone areas of northern and central Wyoming. The strongest winds occurred in the vicinity of Clark where gusts as high as 93 mph were recorded. In central Wyoming, some of the highest wind gusts included 83 mph at the Fales Rock RAWS site in the Green Mountains and 68 mph along Wyoming Boulevard south 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 Feb 13, 3:45 PM MST, 2 hours 30 minutes earlier.
Area Forecast Discussion National Weather Service Riverton WY 345 PM MST Tue Feb 13 2018 .SHORT TERM...(This evening through Friday) Issued at 120 PM MST Tue Feb 13 2018 Inversions are holding strong in the snow-covered basins and we may have to deal with those until the front comes through Thursday. Some of the guidance is still trying to bring a nw wind down to the Riverton area tonight but we'll see. We've been surprised a couple times this winter with apparently strong inversions giving way to a nighttime breeze. If not, another chilly night, especially down low. Lowered highs the next couple days for the Wind River and Big Horn Basins. Wind will be cranking up across the wind corridor and Cody Foothills tonight. In fact, parts of Cody have already gusted over 40 mph today. Outer Dr. in Casper is already gusting near 50 mph. Will upgrade both to warnings (Cody after 00z and wind corridor after 03z.). Winds will gradually increase into Wednesday across the wind corridor and quickly this evening in the Cody Foothills. Cross- sections and upstream soundings are still showing mountain wave potential with near mountain top inversion, 36-40kt flow into the barrier and a calculated froude near 1. On top of that, the thermal gradient looks pretty strong in the 14-16C range at H7. So both mountain wave and gap flow will be in play. The favored gap flow areas could be quite windy, especially Canyon Rd west of Clark where I'm sure winds in the 80-90kt range will be occurring. Other favored areas impacting traffic and more people could easily be in the 60+ range with some 70 mph plus gusts possible. In the wind corridor, gusts on Outer Dr could start hitting high winds early this evening and then increase into Wednesday morning. Other areas may take longer to reach near high or high wind but they will be increasing through the night and impacting travel. Snow starts to develop in the nw mountains Wednesday afternoon with some steady snow Wed night before gradually tapering off Thursday. East of the divide, the cold front will move quickly south from the early morning hours Thursday into the midday timeframe. Snow will spread into the nrn zones Thursday morning with mainly sub-advisory amounts. The far nrn parts, especially nrn Johnson will still have to be watched but for now going 2-3 inches. Lesser amounts as you go south and southwest through Central WY. Clearing Thu night and chilly. Friday we see another quick hitting shortwave in the nw flow bringing another bout of snow to the nrn/nwrn mountains with increasing w-sw flow ahead of it. Any snow that occurs east of the divide with this system will probably hold off until Friday evening. .LONG TERM...(Friday night through Tuesday) Issued at 120 PM MST Tue Feb 13 2018 Mid- to upper-level NW flow will continue to stream moisture and weak energy toward Wyoming Friday night into Saturday, as a shortwave trough moves from southern Alberta through eastern MT. NW mountains should see several inches of snow as a result, and a quick moving weak front will push the winds to northerly across the northern Big Horn Basin and northern Johnson county early Saturday morning. All model guidance is then suggesting more zonal westerly flow Sunday, with continued moist upslope flow from the Alpine- Jackson area northward. YNP and the Tetons look to gain the most from the pattern. From Sunday night onward, the models though are in quite a bit of disagreement. Consensus is for more widespread snow Sunday night into Monday, with the ECMWF being the most aggressive. All models do however bring down another cold front from the north east of the divide on Monday morning. Tuesday then could either be a cold post- frontal regime as the upper level low slides southward (ECMWF), or widespread precipitation and strong northerly flow across the eastern 2/3 of the state (GFS). && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 345 PM MST Tue Feb 13 2018 Weak high pressure will continue over the area this evening with mostly clear skies. VFR conditions are expected at the TAF sites through 15Z/Wed when lowering clouds will bring light showers in western WY around KJAC. Breezy to windy conditions will continue through the night around KCOD and KCPR. KCOD should see an increase overnight, while KCPR will see the strongest wind after 18Z/Wed. KLND and KRKS should also see windy conditions after 18Z/Wed. Increasing moisture in SW mid-level flow will obscure the terrain of western WY Wednesday late morning into the afternoon, with light snow showers expected around KJAC (MVFR conditions) and possible around KPNA. Areas of turbulence can also be expected through the period near the mountains as well as with LLWS. && .FIRE WEATHER... Issued AT 120 PM MST Tue Feb 13 2018 Winds will be on the increase again across the Cody Foothills today into Wednesday and also across the Wind Corridor from Jeffrey City to Casper. The lee of the mountain ranges and also the area from Dubois to near Riverton will also likely see increasing wind today and tonight. The light snow will return to the northwest Wednesday and spread east of the divide Wednesday night into Thursday morning with a gusty north to northeast wind. && .RIW WATCHES/WARNINGS/ADVISORIES... High Wind Warning from 8 PM this evening to 5 PM MST Wednesday for WYZ019-020. High Wind Warning from 5 PM this afternoon to 11 AM MST Wednesday for WYZ003. && SHORT TERM...Skrbac LONG TERM...McDonald AVIATION...McDonald FIRE WEATHER...Skrbac
Hazardous Weather Outlook National Weather Service Riverton WY 222 PM MST Tue Feb 13 2018 WYZ001>020-022>030-141200- 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- 222 PM MST Tue Feb 13 2018 ...High Wind Warning for parts of Central Wyoming tonight and Wednesday... This Hazardous Weather Outlook is for Western and Central Wyoming. .DAY ONE...Today and Tonight Very strong winds along the Cody Foothills and Wind Corridor from Jeffrey City to Casper. .DAYS TWO THROUGH SEVEN...Wednesday through Monday Wednesday...Very strong winds along the Cody Foothills and Wind Corridor from Jeffrey City to Casper. Wednesday and Thursday...Snow across the west starting by Wednesday afternoon, continuing into Thursday. Snow will start over the Bighorns Wednesday night. Saturday night through Monday night...A chance of snow in the west. A chance of snow central and east Sunday through Monday. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report wind gusts over 45 mph. Thank you. Team Riverton
The national radar mosaic for the moment the first event began.
3 high wind. Local standard time, as filed.
High winds occurred in portions of the Cody Foothills. The strongest wind gust recorded was 93 mph 5 miles west-northwest of Clark.
High winds occurred in the higher elevations of the Green Mountains. The highest wind gust recorded was 83 mph at the Fales Rock RAWS site.
High winds occurred in much of Natrona County. The strongest gust was 68 mph along Wyoming Boulevard. Other notable gusts included 62 mph at the Casper airport and 60 mph at 20 mile hill along Interstate 25.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2018Every state in 2018This day in weather historyWarnings in Wyoming, February 2018
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: 738625, 738626, 738627.