Strong west to southwest winds with gusts to around 65 mph developed in the wind corridors near Arlington and Bordeaux.
Every event with a place to put it; 2 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 CYS wrote it up.
Strong west to southwest winds with gusts to around 65 mph developed in the wind corridors near Arlington and Bordeaux.
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 Dec 4, 10:14 PM MST, 3 hours 16 minutes earlier.
Area Forecast Discussion National Weather Service Cheyenne WY 1014 PM MST Tue Dec 4 2018 .SHORT TERM...(Late this afternoon through Thursday night) Issued at 225 PM MST Tue Dec 4 2018 Early afternoon water vapor loop showed a shortwave trough moving southeast across eastern SD/NE. Lower clouds associated with this feature over the northern NE Panhandle have cleared, with mostly sunny skies observed. A stronger shortwave was located over MT. A surface trough was aligned north-south just west of the Laramie Range. Pressure and low level gradients were enhanced, resulting in strong and gusty winds over the southern WY wind corridors, i.e., Arlington and south Laramie Range/foothills. Strongest sustained winds and gusts have been relegated to WY zone 110, but have been close at WY zone 116-117. The 12Z GFS/NAM guidance continues to indicate CAG-CPR 850mb gradients near 60mtrs between 00Z and 12Z Wednesday, and CAG-BRX gradients between 60 and 75mtrs for the same time period. 700mb winds, however, remain below 50kt through early Wednesday morning. Surface trough west of Laramie Range shifts east to near the I-25 corridor later this evening. The model time-height cross sections indicate that subsidence may be strong enough to overcome the low level inversion tonight. Issued a High Wind Warning for Arlington/Elk Mountain valid through 5 AM Wednesday, and Bordeaux from 5 PM this afternoon until 5 AM Wednesday. Sustained west to southwest winds 25 to 45 mph will gust up to 65 mph in the warning areas. After winds decrease Wednesday morning, attention turns to the incoming shortwave trough and cold front from the northwest. Snow showers develop over western Carbon County by daybreak, and spread east to the I-25 corridor Wednesday afternoon, and eastern plains Wednesday evening. Periods of light to moderate snow are expected, with upwards of 3 to 5 inches over the higher mountains, with 1 to 2 inches for lower elevations west of I-25. Less than an inch of snow is forecast for the eastern plains. Light snow showers will linger over the southern WY mountains Thursday, with dry conditions elsewhere. High temperatures Wednesday in the 20s and 30s, will cool back into the 20s following Wednesday night/s cold frontal passage. .LONG TERM...(Friday through Tuesday) Issued at 200 PM MST Tue Dec 4 2018 Slow moving split flow upper air pattern will keep the weather relatively quiet through the beginning of the long term period. A decaying high over low block will end Friday with a shortwave trough passing through much of Wyoming and Colorado. A few snow showers and some stronger winds could develop Friday as the shortwave clears the area through Friday evening. A ridge of high pressure aloft will quickly develop behind the shortwave Saturday and Sunday. At the surface, a cold front will be followed by an arctic high that will develop and strengthen over the northern Rockies. Expect much below average temperatures in this time frame ans the high is expected to be rather strong through next weekend. The weather should remain clear through the long term until Tuesday Wednesday when an approaching trough will bring the threat of snow showers and windy conditions back to the forecast. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1011 PM MST Tue Dec 4 2018 VFR for most airports through the overnight hours and most of Wednesday. We do have a cold front/Clipper system moving into the area Wednesday afternoon that will bring lowering conditions and increasing chances for snow. Believe the airports impacted with snow/IFR ceilings will be KCYS and KLAR...but others may need to added as the front draws nearer. && .FIRE WEATHER... Issued at 200 PM MST Tue Dec 4 2018 No fire weather concerns through the end of the week. The cool and unsettled weather pattern will continue with non-critical humidities. Windy conditions will exist across much of southeast Wyoming this afternoon through Wednesday. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...High Wind Warning until 5 AM MST Wednesday for WYZ106-110. NE...None. && SHORT TERM...MAJ LONG TERM...AL AVIATION...GCC FIRE WEATHER...MAJ
Hazardous Weather Outlook National Weather Service Cheyenne WY 922 AM MST Tue Dec 4 2018 WYZ106-110-116-117-051630- Central Laramie Range and Southwest Platte County- North Snowy Range Foothills-South Laramie Range- South Laramie Range Foothills- 922 AM MST Tue Dec 4 2018 This hazardous weather outlook is for portions of south central Wyoming and southeast Wyoming. .DAY ONE...TODAY AND TONIGHT West to southwest winds will become strong and gusty this afternoon and continue through late tonight. Gusts of 50 to 60 mph are likely. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY Snow will develop over Carbon County Wednesday morning and spread east to the high plains of southeast Wyoming Wednesday afternoon and evening. Travel impacts will be possible along and west of Interstate 25. .Spotter information statement... Spotter activation will not be required. WYZ101>105-107>109-111>115-118-119-051630- Converse County Lower Elevations-Niobrara County- North Laramie Range-Ferris/Seminoe/Shirley Mountains- Shirley Basin-East Platte County-Goshen County- Central Carbon County-Southwest Carbon County-Sierra Madre Range- Upper North Platte River Basin-Snowy Range-Laramie Valley- Central Laramie County-East Laramie County- 922 AM MST Tue Dec 4 2018 This hazardous weather outlook is for portions of east central Wyoming...south central Wyoming and southeast Wyoming. .DAY ONE...TODAY AND TONIGHT No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY Snow will develop over Carbon County Wednesday morning and spread east to the high plains of southeast Wyoming Wednesday afternoon and evening. Travel impacts will be possible along and west of Interstate 25. .Spotter information statement... Spotter activation will not be required. NEZ002-003-019>021-054-055-095-096-051630- Dawes-Box Butte-Scotts Bluff-Banner-Morrill-Kimball-Cheyenne- North Sioux-South Sioux- 922 AM MST Tue Dec 4 2018 This hazardous weather outlook is for portions of western Nebraska. .DAY ONE...TODAY AND TONIGHT No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY The probability for widespread hazardous weather is low. .Spotter information statement... Spotter activation will not be required.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
914 PM MST TUE DEC 4 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0900 PM NON-TSTM WND GST 9 S WHEATLAND 41.92N 104.96W
12/04/2018 M57 MPH PLATTE WY DEPT OF HIGHWAYS
THIS IS WYDOT SITE BORDEAUX. SUSTAINED WIND 42 MPH.
0905 PM HIGH SUST WINDS 7 NW ELK MOUNTAIN 41.76N 106.51W
12/04/2018 M40 MPH CARBON WY DEPT OF HIGHWAYS
THIS IS WYDOT SITE HALLECK RIDGE.
&&
DDEALThe national radar mosaic for the moment the first event began.
2 high wind. Local standard time, as filed.
A mesonet sensor near Wheatland measured a peak wind gust of 58 mph. In addition, a WYDOT sensor at Bordeaux measured sustained winds of 40 mph or higher.
The WYDOT sensor at Halleck Ridge measured sustained winds of 40 mph or higher. Several other WYDOT sensors recorded wind gusts up to 60 mph during this period in addition.
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, December 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: 795474, 795479.