Strong winds occurred in the North Snowy Range Foothills during the overnight of the 9th and morning of the 10th. A Wyoming Department of Transportation site along Interstate 80 at County Road 402 or three miles east-southeast of Elk Mountain measured a peak wind gust of 66 knots.
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The episode as NWS CYS wrote it up.
Strong winds occurred in the North Snowy Range Foothills during the overnight of the 9th and morning of the 10th. A Wyoming Department of Transportation site along Interstate 80 at County Road 402 or three miles east-southeast of Elk Mountain measured a peak wind gust of 66 knots.
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 Cheyenne, WY wrote its last area forecast discussion before the first event at Feb 9, 9:55 PM MST, 29 minutes earlier.
Area Forecast Discussion National Weather Service Cheyenne WY 955 PM MST Sun Feb 9 2020 .UPDATE... Issued at 949 PM MST Sun Feb 9 2020 |Looking at latest WYDOT webcams and night time satellite imagery...looks like the fog over the Summit has moved south into northern Colorado. Went ahead and cancelled the fog advisory early as impacts on the Summit have ceased. Updates have been sent. UPDATE Issued at 704 PM MST Sun Feb 9 2020 Latest WYDOT webcams across the Summit and Vedauwoo showing areas of dense freezing fog along with visibility measurements of under a quarter mile. Went ahead with a freezing fog advisory till 1 AM for the WYZ116. && .SHORT TERM...(This evening through Monday night) Issued at 245 PM MST Sun Feb 9 2020 Early afternoon WV/IR imagery revealed a split flow pattern aloft, with a southern stream cutoff low over central CA and progressive northern stream trough from the Upper Midwest to the central Rocky Mountain region. Surface cold front extended from central IA through southeast KS, central OK to eastern NM. Pacific moisture was streaming northeast across the Four Corners region. Weak isentropic lift was producing light snow showers along the I-80 corridor from west of Laramie east through Cheyenne and Kimball. The precipitation will gradually taper off through late afternoon and early evening. Despite the occasional high cloudiness, overnight lows will plummet into the single digits and lower teens, with sub-zero readings for the valleys west of the Laramie Range. Next Alberta clipper and associated cold front is forecast to quickly move to the southeast across MT, WY and the Dakotas Monday. Snow showers will develop over north-central WY by Monday morning, spread into southeast WY Monday afternoon, and taper off Monday evening. Accumulations will vary from less than an inch lower elevations, to two inches over the mountains. High temperatures Monday will be a few degrees milder for the high plains compared to Sunday. Gusty northwest winds will develop in the wake of the frontal passage. Expect even colder low temperatures Monday night as skies clear and winds diminish, ranging from the single digits above zero east of I-25 and single digits below zero west of I-25. .LONG TERM...(Tuesday through Sunday) Issued at 245 PM MST Sun Feb 9 2020 Split flow transitions to a progressive high-amplitude pattern by Wednesday, with a couple of trough and ridge passages into next weekend. Northwest flow aloft will prevail through Thursday between a upper ridge to the west and upper trough to the east. This will allow another Alberta clipper to push southeast into the Northern Plains and Upper Midwest. Temperatures will continue below normal with highs in the 20s and 30s and overnight lows in the single digits and teens. Westerly winds will be increasing for wind-prone areas beginning Tuesday afternoon as 700/850mb CAG-CPR gradients rise above 60mtrs, and remain elevated through Wednesday morning. 700-800mb winds increase to 40-45kts. Winds and gradients decrease late Wednesday, but increase once again Thursday evening into Friday morning. High temperatures will moderate into the 30s and 40s Friday with the passage of a ridge and southwest flow aloft ahead of the next Pacific trough moving through the CWA Saturday. Cooler temperatures Saturday will moderate once again Sunday as the flow aloft becomes westerly. With regards to precipitation, there will be chances for snow showers Wednesday, and Friday through Sunday. The higher elevations can expect some accumulation, with lesser amounts for lower elevations. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 415 PM MST Sun Feb 9 2020 Some MVFR cigs around KCYS early this evening otherwise VFR expected at all terminals overnight into Monday. Weak front will move across the area early Monday switching winds out of a northerly direction behind it. Some snow showers possible across mainly the mtns of se Wy Monday afternoon. && .FIRE WEATHER... Issued at 230 PM MST Sun Feb 9 2020 Existing snow pack, cold temperatures, non-critical humidities and chances for more precipitation will preclude fire weather concerns through most of the week. It will be breezy to windy during the mid- to-late week period. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && UPDATE...GCC SHORT TERM...MAJ LONG TERM...MAJ AVIATION...RE FIRE WEATHER...MAJ
Hazardous Weather Outlook National Weather Service Cheyenne WY 1053 AM MST Sun Feb 9 2020 NEZ054-WYZ103>107-109>119-101800- Kimball-North Laramie Range-Ferris/Seminoe/Shirley Mountains- Shirley Basin-Central Laramie Range and Southwest Platte County- East Platte County-Central Carbon County- North Snowy Range Foothills-Southwest Carbon County- Sierra Madre Range-Upper North Platte River Basin-Snowy Range- Laramie Valley-South Laramie Range-South Laramie Range Foothills- Central Laramie County-East Laramie County- 1053 AM MST Sun Feb 9 2020 This hazardous weather outlook is for portions of western Nebraska...south central Wyoming and southeast Wyoming. .DAY ONE...TODAY AND TONIGHT Occasional snow showers will persist into the afternoon hours, mainly along and south of the Interstate 80 corridor. Additional accumulations will be less than an inch. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY Winds will increase late Tuesday and early Wednesday for the wind prone areas of southeast Wyoming. .Spotter information statement... Spotter activation will not be required. NEZ002-003-019>021-055-095-096-WYZ101-102-108-101800- Dawes-Box Butte-Scotts Bluff-Banner-Morrill-Cheyenne-North Sioux- South Sioux-Converse County Lower Elevations-Niobrara County- Goshen County- 1053 AM MST Sun Feb 9 2020 This hazardous weather outlook is for portions of western Nebraska...east central Wyoming and southeast Wyoming. .DAY ONE...TODAY AND TONIGHT No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY The probability for widespread hazardous weather is low. .Spotter information statement... Spotter activation will not be required.
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
Wyoming Department of Transportation site along Interstate 80 at County Road 402 or three miles east-southeast of Elk Mountain measured the reported peak wind gust.
After NWS Directive 10-1605, the rules offices file Storm Data by.
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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: 870135.