A period of high winds developed across portions of southeastern Wyoming.
Every event with a place to put it; 19 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.
A period of high winds developed across portions of southeastern Wyoming.
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 Apr 12, 10:22 AM MST, 53 minutes earlier.
Area Forecast Discussion National Weather Service Cheyenne WY 1122 AM MDT Thu Apr 12 2018 .SHORT TERM...(Today through Friday) Issued at 515 AM MDT Thu Apr 12 2018 Very busy morning on the forecast desk with numerous Watches, Warnings and Advisories posted for a mixed bag of weather for the next 2 days. First off, today we are mostly concerned with another round of high winds across southeastern Wyoming where we have High Wind Warnings posted. Gusts to 60 mph with some 70 mph gusts possible in the typically higher gap wind areas. As the gradient tightens, higher winds will start off over the higher elevations west of I-25 this morning, spreading east of the south Laramie Range this afternoon into the early evening. Outdoor burning is highly discouraged again today with the strong winds and low humidity, and we do have another round of Red Flag Warnings posted east of the Laramie Range and south of Wheatland and Torrington today where RH values will drop to around 15 percent with strong winds above 40 mph. Our attention then turns to the upper trough moving onto the west coast today, that will start to deepen and stack significantly during the day on Friday to the east of our region. As the low starts to deepen, a persistent area of moderate to heavy snow on the northwest side of the system is still expected to bring impacts to the northeastern zones of our forecast area through the day on Friday. We kept the highest snow totals around the Chadron and Alliance areas, closer to the ensemble model means projections, with just under a foot of snow in those areas by tomorrow night (and where we keep the Winter Storm Watches going that will likely be upgraded to Winter Storm Warnings later today). We kept Niobrara county in the Winter Storm Watch for this issuance even though we have been trending down with expected snowfall totals that area. The potential that 4 to 6 inches of snow that area combined with strong winds could result in having to issue a Blizzard Warning. Same goes for much of the Nebraska Panhandle with the exception of Banner and Kimball counties where confidence in much lower totals is seen...but to the east from Alliance down to Sidney and even around Scottsbluff there may be enough snow with the wind effects to bring significant impacts, so we added those zones to the Winter Storm Watch for now. Farther west, we highlight High Wind Watches for tomorrow with an inch or so of snow by tomorrow evening. The higher elevations in the mountains of southern Wyoming are expected to get 6 to 12 inches of snowfall on the western facing slopes, so we added Winter Weather Advisories starting late today for those zones. .LONG TERM...(Friday night through Wednesday) Issued at 515 AM MDT Thu Apr 12 2018 Models show slowly improving conditions late Friday night and early Saturday as the strong storm system across the plains continues to move east across far eastern Nebraska and Kansas. Winds will be slow to diminish in intensity through the next with gusts over 40 mph still common over the eastern plains. && .AVIATION...(For the 18Z TAFS through 18Z Friday morning) Issued at 1120 AM MDT Thu Apr 12 2018 VFR prevails through this afternoon with lowering CIGS this evening and overnight tonight. MVFR CIG/VIS will spread southwest into KCDR and KAIA after 06Z. Strong westerly winds will impact aviation operations with gusts around 50 kt at KRWL and KLAR this afternoon, and 35-45 kt elsewhere in southeast Wyoming. Moderate to strong mountain wave turbulence is expected in these areas into late this evening. South to southeast winds will prevail for the Nebraska Panhandle with gusts around 25 knots. Rain showers will gradually spread northeast across Carbon and Albany counties this afternoon behind the front, and further east tonight. && .FIRE WEATHER... Issued at 515 AM MDT Thu Apr 12 2018 High winds and low relative humidity for areas along and east of Interstate 25 in southeastern Wyoming today will result in critical fire weather conditions for areas south of Wheatland and Torrington. Also to be closely monitored today will be the southern sections of zone 308 where humidity values will fall to around 18 percent with strong west to southwesterly winds gusting around 55 mph...which could lead to an upgrade to a Red Flag Warning in that area should humidity levels fall below expected levels. Humidity values will recover tonight and Friday ahead of a winter storm system that is poised to move across eastern Wyoming and the western Nebraska Panhandle Friday and Friday night. && .CYS WATCHES/WARNINGS/ADVISORIES... && SHORT TERM...JG LONG TERM...TJT AVIATION....MAJ FIRE WEATHER...JG
Hazardous Weather Outlook National Weather Service Cheyenne WY 547 AM MDT Thu Apr 12 2018 WYZ101>119-131200- Converse County Lower Elevations-Niobrara County- North Laramie Range-Ferris/Seminoe/Shirley Mountains- Shirley Basin-Central Laramie Range and Southwest Platte County- East Platte County-Goshen 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- 547 AM MDT Thu Apr 12 2018 This hazardous weather outlook is for portions of east central Wyoming...south central Wyoming and southeast Wyoming. .DAY ONE...TODAY AND TONIGHT High Winds with gusts to near 60 mph today will occur over a large portion of southern and southeastern Wyoming. These strong winds will pose a hazard to those driving high profile vehicles as well as those pulling light trailer loads such as RV's and campers. Very low humidity values for areas along and east of I-25 and south of Wheatland will combine with the high winds today to increase the potential for wildfires. Outdoor burning today is highly discouraged just about anywhere in eastern Wyoming due to the high winds. By tonight, snow showers will be increasing in intensity over the mountains of southern Wyoming where Winter Weather Advisories have been posted starting late today. Snow will begin to spread eastward onto the high plains of eastern Wyoming and western Nebraska late tonight. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY Snow will continue across eastern Wyoming into the early evening hours bringing the potential for travel impacts due to blowing snow across the region. The heaviest snowfall of 4 inches or more is projected to fall from around Lusk eastward into South Dakota and the northern Nebraska Panhandle. Heavier snowfall of 6 to 12 inches is projected for the Sierra Madre and Snowy Ranges as well...with lesser amounts in the lower elevations of southeastern Wyoming. Snow combined with strong winds on Friday will pose a potential for periodically low visibilities and slick roads due to blowing snow. Conditions are expected to begin improving Friday night with no significant weather expected over the weekend into early next week. .Spotter information statement... Spotter reports of snowfall will be valuable through Friday night and greatly appreciated. NEZ002-003-019>021-054-055-095-096-131200- Dawes-Box Butte-Scotts Bluff-Banner-Morrill-Kimball-Cheyenne- North Sioux-South Sioux- 547 AM MDT Thu Apr 12 2018 This hazardous weather outlook is for portions of western Nebraska. .DAY ONE...TODAY AND TONIGHT No significant weather concerns are expected through today. Snow showers will be moving in from the west late tonight with some snow accumulations expected by Friday morning across the northern Nebraska Panhandle. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY Snow will increase in coverage and intensity through the day on Friday as much colder air moves in behind a cold front. The heaviest snowfall is expected Friday afternoon and evening as a strong low pressure system deepens over Kansas. Significant travel impacts from several inches of snow combined with strong winds is possible Friday and Friday night, especially for areas northeast of a Scottsbluff to Sidney line. Winter Storm Watches are in effect for these areas, with the worst conditions for snow, blowing snow and very low visibilities expected to be in the Chadron to Alliance areas Friday afternoon and evening. Conditions are expected to begin improving Friday night with no significant weather expected over the weekend into early next week. .Spotter information statement... Spotter reports of snowfall will be valuable through Friday night and greatly appreciated.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
927 AM MDT THU APR 12 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0915 AM NON-TSTM WND GST 6 WNW BUFORD 41.14N 105.41W
04/12/2018 M58 MPH ALBANY WY COUNTY OFFICIAL
VEDAUWOO WYDOT SENSOR..
&&
MJAMSKIPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
1045 AM MDT THU APR 12 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1045 AM HIGH SUST WINDS 6 WNW BUFORD 41.14N 105.41W
04/12/2018 M42 MPH ALBANY WY DEPT OF HIGHWAYS
VEDAUWOO WYDOT SENSOR. SUSTAINED 40-42 MPH FOR PAST HOUR.
&&
MJAMSKIPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHEYENNE WY
1157 AM MDT THU APR 12 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1135 AM NON-TSTM WND GST RAWLINS 41.78N 107.23W
04/12/2018 M59 MPH CARBON WY AMATEUR RADIO
&&
MJAMSKIThe national radar mosaic for the moment the first event began.
19 high wind. Local standard time, as filed.
The HADS sensor at Seminoe Dam measured sustained winds of 40 mph or higher.
The wind sensor at the Rawlins Airport measured a peak gust of 59 mph.
The WYDOT sensor at Walcott Junction measured a peak wind gust of 66 mph.
The WYDOT sensor at Arlington measured sustained winds of 40 mph or higher.
The WYDOT sensor at Quealy Dome measured sustained winds of 40 mph or higher.
The WYDOT sensor at Shirley Rim measured sustaijned winds of 40 mph or higher.
The WYDOT sensor at County Road 402 measured peak wind gusts of 63 mph.
The WYDOT sensor at Dana Ridge measured peak wind gusts of 58 mph.
The WYDOT sensor at Herrick Lane measured a peak wind gust of 58 mph.
The WYDOT sensor at Halleck Ridge measured peak wind gusts of 58 mph.
The WYDOT sensor at Wagonhound measured peak wind gusts of 58 mph.
The UPR sensor at Rock River measured a peak wind gust of 62 mph.
The UPR sensor at Emkay measured sustained winds of 40 mph or higher.
The WYDOT sensor at Buford East measured sustained winds of 40 mph or higher.
The WYDOT sensor at Interstate 80 mile post 353 measured sustained winds of 40 mph or higher.
The WYDOT sensor at Otto Road measured sustained winds of 40 mph or higher.
The WYDOT sensor at Wyoming Hill measured sustained winds of 40 mph or higher.
The WYDOT sensor at Interstate 80 mile post 373 measured sustained winds of 40 mph or higher.
The UPR sensor at Buford measured sustained winds of 40 mph or higher.
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, April 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: 764170, 764177, 764178, 764160, 764181, 764171, 764163, 764166, 764180, 764168, 764169, 764183, 764187, 764184, 764188, 764189, 764193, 764199, 764185.