Period of high sustained winds were measured by the Wyoming Department of Transportation sensor at Halleck Ridge seven miles northwest of Elk Mountain along Interstate 80. 86 mph averaged over an hour period.
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Period of high sustained winds were measured by the Wyoming Department of Transportation sensor at Halleck Ridge seven miles northwest of Elk Mountain along Interstate 80. Peak sustained wind was 43.86 mph averaged over an hour period.
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 Mar 20, 4:22 AM MST, 3 hours 52 minutes earlier.
Area Forecast Discussion National Weather Service Cheyenne WY 522 AM MDT Sat Mar 20 2021 .SHORT TERM...(Today through Sunday Night) Issued at 310 AM MDT Sat Mar 20 2021 Latest water vapor loop was showing the upper level trof moving through the northwest U.S. This system is showing quite a bit of jet energy on the leading edge of this trof with a decent moisture plume. With this jet energy on the warm side of this system and decent lift along the front may set the stage for a few thunderstorms to develop in southwest Wyoming and push into Carbon county parts of Albany county during the late afternoon into the early evening. The HREF seems to pickup on this scenario and there is also some concern for some thundersnow/snow squalls as well especially above 7000ft where rates could exceed 1 inch an hour for a short period (2-3 hours) along and behind the front. This is something that the day/evening shift will need to keep an eye on. Otherwise, the bulk of the convection should begin to fizzle out around midnight as the jet energy gets focused further south into Colorado along with decent subsidence. However, the moisture will still be in place and the combination of upslope flow behind the front will provide good orographics for the Sierra Madre and Snowy Ranges. As a result, we could see a 3 to 5 inches of snow in this area by Monday morning. Meanwhile, the high winds around Arlington are not looking took promising at this particular time. The 700mb-800mb height gradient does increase during the early evening behind the front, but still not confident enough to issue a High Wind Warning. Therefore, we will late the day shift take another look before making the decision on whether to cancel it or not. A cooler and more unsettled Sunday is setting over the area due to the influence of the upper level trof. The residual moisture combined with cool temperatures aloft will most likely set the stage for some scattered snow showers/snow squalls mainly in southeast Wyoming. The GFS/NAM are both indicating the potential for snow squalls based on the snow squall parameter. Not expecting much in the way of accumulation with the bulk of these snow showers due to the high sun angle and temperatures hovering in the low to mid 30s. However, if we see high enough rates, it could cause slick roadways. The convection should begin to dissipate after sunset. .LONG TERM...(Monday through Saturday) Issued at 235 PM MDT Fri Mar 19 2021 Pattern remains fairly progressive through the week as a series of mid-level troughs push through the region. This will keep temperatures cooler throughout the week, with highs in the high 30s to low 40s, as compared to the temperatures from the weekend prior. In addition, as the series of pacific troughs dig through the region, combined with low level moisture, will increase our chances for some rain/snow throughout the week. The first chance in the extended forecast occurs on Tuesday. As a deepening low pressure cell spins off towards the Midwest, a pacific trough continues to dig to the east/southeast. Should be fairly quick hitting in terms of wide-spread precipitation starting out as a rain/snow mix before changing over to snow in the evening. Still not expecting much out of this system at this time with a lack of upper level support. The main concern during this time frame is the strength and positioning of the deepening low pressure cell that develops on the southeastern corner of Colorado. As this time, it appears that the low stays a bit too far to the south and does not really strengthen till it pushes further out to the east. However, it should be worth noting that if this cell shifts more northward, could result in some impacts for southeastern Wyoming and the Nebraska Panhandle. Looking ahead into the middle of the week, models have come in much better alignment with precipitation for Wednesday into Thursday as the next Pacific Trough pushes through the region. The GFS now keeps the area much more drier as compared to previous runs. Next shot for some widespread precipitation occurring later this week, as a positively tilted trough, with its axis extending all the way through the four corners into Arizona, begins slowly digging to the south/southeast across the CWA beginning Friday morning and lasting into the weekend. Current estimates for QPF expend to around 0.25 inches, with nighttime lows in the low 20s. && .AVIATION...(For the 12Z TAFS through 12Z Sunday morning) Issued at 515 AM MDT Sat Mar 20 2021 VFR conditions expected for most terminals in the forecast period. The two terminals that are excluded from this are KRWL and KBFF. Favorable valley winds, clear skies, and saturated lower levels are fairly conducive for fog development at KBFF. There is a bit of uncertainty to the exact timing, and as a result pushed back the start time to around 7am MDT. This site will require continual monitoring for any amendments that might be needed if the fog develops a bit sooner than anticipated. The second terminal that is expected to drop into IFR conditions is KRWL with the approach of the frontal system. There remains a general Thunderstorm risk for Carbon County. But it is worth noting that SPC outlook indicating this risk are on the western side of the CWA and continue to push further west. Nevertheless, the arrival of the front that moves through Saturday evening will lower the visibilities with a strong chance for light blowing snow at KRWL. && .FIRE WEATHER... Issued at 310 AM MDT Sat Mar 20 2021 As much of the region remains snow covered, and some more precipitation expected throughout the week, fire weather concerns remain low. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...High Wind Watch through this evening for WYZ110. NE...None. && SHORT TERM...REC LONG TERM...MD AVIATION...MD FIRE WEATHER...MD
Hazardous Weather Outlook National Weather Service Cheyenne WY 434 AM MDT Sat Mar 20 2021 WYZ101-103>107-109>118-211045- Converse County Lower Elevations-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- 434 AM MDT Sat Mar 20 2021 This hazardous weather outlook is for portions of east central Wyoming...south central Wyoming and southeast Wyoming. .DAY ONE...TODAY AND TONIGHT A cold front is expected to move through the area late this afternoon into the early evening and bring some rain/snow showers and thunderstorms to parts of Carbon and Albany counties. 3 to 5 inches of snowfall will also be possible over the Sierra Madre and Snowy Ranges tonight into Sunday. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY An unsettled weather pattern is expected through much of the week. As a result, there will be periods of snowfall through the week, but accumulation amounts appear to be minimal at this time. .Spotter information statement... Spotter activation will not be needed. NEZ002-003-019>021-054-055-095-096-WYZ102-108-119-211045- Dawes-Box Butte-Scotts Bluff County-Banner County-Morrill- Kimball County-Cheyenne-North Sioux-South Sioux-Niobrara County- Goshen County-East Laramie County- 434 AM MDT Sat Mar 20 2021 This hazardous weather outlook is for portions of panhandle Nebraska...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...SUNDAY THROUGH FRIDAY An unsettled weather pattern is expected through much of the week. As a result, there will be periods of snowfall through the week, but accumulation amounts appear to be minimal at this time. .Spotter information statement... Spotter activation will not be needed.
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
Period of high sustained winds were measured by the Wyoming Department of Transportation sensor at Halleck Ridge seven miles northwest of Elk Mountain along Interstate 80.
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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: 938331.