A brief period of high winds were measured by a couple of Wyoming Department of Transportation sensors along Interstate 25 in Platte and Laramie Counties on the 19th. Coleman sensor in Platte measured a peak wind gust of 59 mph while the Bear Creek sensor in Laramie measured a period of sustained winds of 40 mph.
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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 CYS wrote it up.
A brief period of high winds were measured by a couple of Wyoming Department of Transportation sensors along Interstate 25 in Platte and Laramie Counties on the 19th. Coleman sensor in Platte measured a peak wind gust of 59 mph while the Bear Creek sensor in Laramie measured a period of sustained winds of 40 mph.
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 Nov 19, 4:36 AM MST, 5 hours 18 minutes earlier.
Area Forecast Discussion National Weather Service Cheyenne WY 436 AM MST Thu Nov 19 2020 .SHORT TERM...(Today - Friday) Issued at 301 AM MST Thu Nov 19 2020 Winds over the I-80 Summit have not been particularly strong early this morning, with peak gusts only around 30-35 MPH in the Buford/ Wildcat Trail areas over the past few hours. High-resolution model guidance continues to suggest an increasing pressure gradient over the southern Laramie Range through 12-15z along w/ increasing low- level subsidence. It is quite possible this may still yield higher wind gusts over 50 knots around sunrise. The High Wind Warning for the South Laramie Range remains in effect until 5 AM MST today. We will continue to monitor observational trends to assess a possible need to extend the headline into the mid-morning hours. Scattered snow showers are expected today, mainly over our western zones as a result of active mid & upper-level flow and appreciable instability with cooling thermal profiles aloft. One area of focus today will be across Carbon & Albany counties, as the RRQ of a 120 to 130 knot H25 jet interacts with the 700 mb cold front. This may enhance low-level frontogenesis and result in some snow banding in those areas. GFS & NAM forecast soundings both suggest a very well mixed boundary layer w/ potential for MUCAPE of at least 50-100 J/ kg. There is definitely some concern for local convective bursts & snow squalls, especially given the gradient/mixing winds which may already be quite strong (40+ knots) to begin with. We will message this potential in our morning social media package. Otherwise, low impacts expected from this winter event w/ an inch or two expected in the mountains and localized areas of minor accumulations in any areas impacted by snow squalls. Temperatures above freezing should also limit the duration of any road impacts from snow today. Quiet weather is expected for Friday as the trough axis shifts eastward, bringing in a considerably cooler & drier air mass. .LONG TERM...(Friday Night - Wednesday) Issued at 301 AM MST Thu Nov 19 2020 There is a lower chance of precipitation of snowfall on Saturday morning. Sunday morning temperatures drop significantly trending the mid teens to lower 20s. Mountain areas can expect wind chills in the single digits. A dry period begins Sunday afternoon into Monday afternoon where mostly clear skies will soon turn to overcast. Isolated snow showers are possible in the mountains but elsewhere can expect dry conditions and maximum temperatures reaching the lower 50s Monday afternoon. There is a lack of moisture for the rest of next week and above-average temperatures will continue. Elevated winds are possible next Wednesday afternoon although uncertainty is high due to long range forecasts and model consistency. && .AVIATION...(For the 12Z TAFS through 12Z Friday morning) Issued at 432 AM MST Thu Nov 19 2020 VFR conditions are expected to prevail at most terminals, with the exception of KRWL where scattered snow showers may result in lower (MVFR/IFR) ceilings & visibilities at times through mid afternoon. Gusty winds are expected for all terminals today, mainly after 17z with the strongest winds expected west of I-25. Gusts in excess of 40 knots are possible for KRWL/KLAR/KSAA. Snow squalls could occur near these terminals, posing a risk for sudden whiteout conditions later this morning into the afternoon hours. && .FIRE WEATHER... Issued at 301 AM MST Thu Nov 19 2020 No fire weather concerns. Despite periods of gusty winds, a cooler air mass will keep RH values well outside of critical thresholds. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...High Wind Warning until 5 AM MST early this morning for WYZ116. NE...None. && SHORT TERM...CLH LONG TERM...AW AVIATION...CLH FIRE WEATHER...CLH
Hazardous Weather Outlook National Weather Service Cheyenne WY 512 AM MST Thu Nov 19 2020 WYZ104-105-109>115-201215- Ferris/Seminoe/Shirley Mountains-Shirley Basin- Central Carbon County-North Snowy Range Foothills- Southwest Carbon County-Sierra Madre Range- Upper North Platte River Basin-Snowy Range-Laramie Valley- 512 AM MST Thu Nov 19 2020 This hazardous weather outlook is for portions of south central Wyoming and southeast Wyoming. .DAY ONE...TODAY AND TONIGHT Snow squalls are possible over portions of Carbon and Albany counties today. Motorists traveling west and northwest of Laramie on Interstate 80 or Highway 287 should be prepared for sudden whiteout conditions in snow and blowing snow. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY The probability for widespread hazardous weather is low. .Spotter information statement... Spotters are encouraged to report significant weather to the National Weather Service in Cheyenne.
The national radar mosaic for the moment the first event began.
2 high wind. Local standard time, as filed.
Wyoming Department of Transportation sensor along Interstate 25 at Coleman measured the reported wind gust.
Wyoming Department of Transportation sensor along Interstate 25 at Bear Creek measured the one hour plus period of sustained winds of 40 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2020Every state in 2020This day in weather historyWarnings in Wyoming, November 2020
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: 924431, 924432.