Strong winds developed in the upper atmosphere above a large surface pressure difference and produced significant winds across southeast Wyoming.
Every event with a place to put it; 7 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 winds developed in the upper atmosphere above a large surface pressure difference and produced significant winds across southeast 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 Jan 20, 2:27 AM MST, 6 hours 9 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
227 AM MST THU JAN 20 2011
.SHORT TERM...TODAY THROUGH SATURDAY
CURRENTLY...PACIFIC NORTHWEST DOMINATED BY HIGH PRESSURE AND CLEAR
SKIES. THE EXCEPTION BEING RIGHT DOWN HERE BETWEEN CHEYENNE AND
ARLINGTON...WHERE RADAR CONTINUES TO SHOW AN AREA OF LIGHT SNOW.
WYDOT WEBCAMS ARE SHOWING LIGHT TO MODERATE SNOW FROM THE I80
SUMMIT...THROUGH LARAMIE TO JUST EAST OF ARLINGTON. AREA HAS BEEN
FAIRLY PERSISTENT THE PAST FEW HOURS...BUT IS SHOWING SOME SIGNS
OF DECREASING IN COVERAGE. THIS IS LIKELY DUE TO THE SHORTWAVE
THAT IS EVIDENT ON WATER VAPOR IMAGERY MOVING THROUGH SOUTHEAST
WYOMING AT THIS TIME. LOOKS LIKE THE SHORTWAVE SHOULD MOVE THROUGH
BY 6 AM OR SO THIS MORNING.
FOR TODAY...GOING TO SEE AN INCREASE IN WINDS THROUGHOUT THE DAY
WITH THE GFS SHOWING A WESTERLY WIND OF 60KTS AT 700MBS DEVELOPING
BY LATE AFTERNOON. WRF IS A BIT DELAYED ON THIS WIND
DEVELOPING...BUT LOCAL WIND STUDY DEVELOPING A GOOD HEIGHT
DIFFERENCE BETWEEN CRAIG AND CASPER BY MID AFTERNOON. OUR WIND
PRONE AREAS OF ARLINGTON AND BORDEAUX WILL START BLOWING EARLIER
THAN SUGGESTED BY THE STUDY. WENT AHEAD AND WILL ISSUE A HIGH WIND
WARNING FOR THESE TWO ZONES STARTING AT 18Z TODAY AND THE REST OF
THE CENTRAL AND SOUTHERN LARAMIE RANGE AFTER 00Z. WENT AHEAD AND
ADDED CARBON COUNTY TO THE WARNING AS WELL AS THE GFS SHOWS A
130-140KT UPPER LEVEL JET COMING IN PHASE WITH THE 700MB WINDS.
DAY SHIFT MAY NEED TO EXPAND AREAL COVERAGE OF THE WARNING BASED
ON THE 12Z MODEL RUN. THESE WINDS WILL PROVIDE DOWN SLOPING WINDS
EAST OF THE LARAMIE RANGE THIS AFTERNOON AND EVENING TO START
WARMING TEMPERATURES. HAVE GONE WITH MID 20 LOWS TONIGHT WITH
HIGHS FRIDAY IN THE LOW TO MID 40S EAST OF THE LARAMIE RANGE AND
MID 20S EAST.
WINDS LOOK TO INCREASE AGAIN FRIDAY EVENING INTO SATURDAY MORNING
AS 700MB WINDS ONCE AGAIN INCREASE TO 50-60KTS. THIS AHEAD OF THE
NEXT POTENT SHORTWAVE THAT WILL MOVE THROUGH SOUTHERN MONTANA
SATURDAY AFTERNOON...BRINGING US OUR NEXT CHANCE FOR SNOW. THIS
SHORTWAVE DRAGS ANOTHER COLD FRONT INTO THE AREA. KEPT HIGH POPS
GOING FOR SATURDAY AFTERNOON AND EVENING. COULD BE SEEING SOME
WINTER HEADLINES AGAIN...ESPECIALLY FOR THE SNOWY AND SIERRA MADRE
RANGES.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...
CWA WILL CONTINUE TO BE UNDER A GENERALLY NW FLOW ALOFT DURING THE
PERIOD WITH SEVERAL CLIPPER TYPE SYSTEMS PASSING BY EVERY COUPLE OF
DAYS. THESE SYSTEMS WILL BRING SOME LIGHT SNOWS TO PARTS OF THE CWA
AND RELATIVELY MINOR SHOTS OF COOLER AIR AS MUCH COLDER ARCTIC AIR
WILL REMAIN SHUNTED WELL TO THE NORTH AND EAST AS STRONG PACIFIC
FLOW HOLDS OVER MUCH OF NORTH AMERICA. UPPER TROF WILL BE DEPARTING
THE AREA SATURDAY NIGHT WITH ANY LINGERING SNOW ENDING THEN THE NEXT
SYSTEM WILL DROP ACROSS SUNDAY NIGHT INTO MONDAY. SHORT UPPER RIDGE
TRANSLATES ACROSS MONDAY NIGHT THEN NEXT SHORTWAVE MOVES BY TUESDAY
INTO TUESDAY NIGHT. PATTERN WILL PRODUCE BREEZY/WINDY PERIODS AT
TIMES AND KEEP TEMPERATURES CLOSE TO AVERAGES FOR THIS TIME OF THE
YEAR.
&&
.AVIATION...FOR 12Z TAFS...
MAINLY VFR CONDITIONS EXPECTED TODAY AND TONIGHT THOUGH ISOLD MVFR
CIGS POSSIBLE WITH ANY WEAK IMPULSES MOVING BY IN NW FLOW ALOFT.
GUSTY WINDS DVLPG VCTY SE WY MTNS LATE THIS AFTERNOO AND TONIGHT.
&&
.FIRE WEATHER...FIRE WEATHER CONCERNS WILL BE MINIMAL FOR THE NEXT
WEEK DUE TO THE COOL TEMPERATURES AND PERIODS OF SNOWFALL. PERIODS
OF GUSTY WINDS WILL OCCUR.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING FROM 11 AM THURSDAY TO 9 AM FRIDAY FOR WYZ106-
WYZ110.
HIGH WIND WARNING FROM 5 PM THURSDAY TO 9 AM FRIDAY FOR WYZ104-
WYZ105-WYZ109-WYZ114-WYZ116-WYZ117.
NE...NONE.
&&
SHORT TERM/FIRE WEATHER...CLAYCOMB
LONG TERM/AVIATION...REHAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHEYENNE WY 306 AM MST THU JAN 20 2011 WYZ107-111>113-115-118-211015- EAST PLATTE COUNTY-SOUTHWEST CARBON COUNTY-SIERRA MADRE RANGE- UPPER NORTH PLATTE RIVER BASIN-LARAMIE VALLEY- CENTRAL LARAMIE COUNTY- 306 AM MST THU JAN 20 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL WYOMING... SOUTH CENTRAL WYOMING AND SOUTHEAST WYOMING. .DAY ONE...TODAY AND TONIGHT WINDY CONDITIONS ARE EXPECTED TO DEVELOP OVER THE AREA LATE THIS AFTERNOON AND TONIGHT WITH SOME GUSTS IN EXCESS OF 45 MPH POSSIBLE. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY PERIODS OF LIGHT SNOW ARE EXPECTED DURING THE PERIOD WITH THE PASSAGE OF SEVERAL DISTURBANCES. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT. && THIS PRODUCT...ALONG WITH OTHER WEATHER...HYDROLOGIC...AND CLIMATE INFORMATION IS AVAILABLE ON THE WEB AT... HTTP://WEATHER.GOV/CHEYENNE NEZ002-003-019>021-054-055-095-096-WYZ101-102-108-119-211015- DAWES-BOX BUTTE-SCOTTS BLUFF-BANNER-MORRILL-KIMBALL-CHEYENNE- NORTH SIOUX-SOUTH SIOUX-CONVERSE COUNTY LOWER ELEVATIONS- NIOBRARA COUNTY-GOSHEN COUNTY-EAST LARAMIE COUNTY- 306 AM MST THU JAN 20 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN NEBRASKA PANHANDLE...SOUTHEAST WYOMING. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY PERIODS OF LIGHT SNOW ARE EXPECTED DURING THE PERIOD WITH THE PASSAGE OF SEVERAL DISTURBANCES. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT. && THIS PRODUCT...ALONG WITH OTHER WEATHER...HYDROLOGIC...AND CLIMATE INFORMATION IS AVAILABLE ON THE WEB AT... HTTP://WEATHER.GOV/CHEYENNE WYZ103>106-109-110-114-116-117-211015- NORTH LARAMIE RANGE-FERRIS/SEMINOE/SHIRLEY MOUNTAINS- SHIRLEY BASIN-CENTRAL LARAMIE RANGE AND SOUTHWEST PLATTE COUNTY- CENTRAL CARBON COUNTY-NORTH SNOWY RANGE FOOTHILLS-SNOWY RANGE- SOUTH LARAMIE RANGE-SOUTH LARAMIE RANGE FOOTHILLS- 306 AM MST THU JAN 20 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL WYOMING... SOUTH CENTRAL WYOMING AND SOUTHEAST WYOMING. .DAY ONE...TODAY AND TONIGHT STRONG AND GUSTY WESTERLY WINDS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND CONTINUE TONIGHT. HIGH WIND WARNINGS HAVE BEEN ISSUED FOR THE AREA AS A RESULT. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY STRONG AND GUSTY WINDS WILL CONTINUE INTO EARLY FRIDAY MORNING BEFORE DECREASING. AFTER THAT PERIODS OF LIGHT SNOW ARE EXPECTED THROUGH WEDNESDAY WITH THE PASSAGE OF SEVERAL DISTURBANCES. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT. && THIS PRODUCT...ALONG WITH OTHER WEATHER...HYDROLOGIC...AND CLIMATE INFORMATION IS AVAILABLE ON THE WEB AT... HTTP://WEATHER.GOV/CHEYENNE
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE CHEYENNE WY 816 AM MST THU JAN 20 2011 WYZ110-201800- NORTH SNOWY RANGE FOOTHILLS- INCLUDING THE CITIES OF...ARLINGTON...ELK MOUNTAIN 816 AM MST THU JAN 20 2011 ...STRONG WINDS AND BLOWING SNOW WERE OBSERVED IN THE ARLINGTON AREA... WESTERLY WINDS HAVE INCREASED IN THE ARLINGTON AREA SINCE SUNRISE. AT 8 AM...WIND SPEEDS AT ARLINGTON WERE BETWEEN 30 AND 40 MPH WITH GUSTS TO 47 MPH. WITH THE INCREASE IN WINDS... BLOWING SNOW HAS BECOME WIDESPREAD IN THAT AREA WITH VISIBILITIES REDUCED TO A QUARTER MILE OR LESS AT TIMES. THE STRONG WINDS AND BLOWING SNOW WILL CONTINUE IN THE ARLINGTON AREA THE REST OF TODAY AND TONIGHT. IN FACT...WIND GUSTS WILL BE AROUND 60 MPH THIS AFTERNOON AND TONIGHT AND A HIGH WIND WARNING IS IN EFFECT DURING THAT TIME. VISIBILITIES WILL BE GREATLY REDUCED DUE TO THE BLOWING SNOW. MOTORISTS TRAVELING ON INTERSTATE 80 NEAR ARLINGTON CAN EXPECT THE STRONG WINDS AND BLOWING SNOW. TRAVEL WILL BE HAZARDOUS... ESPECIALLY FOR THOSE WITH LIGHTWEIGHT OR HIGH PROFILE VEHICLES DUE TO THE STRONG WINDS...SUDDEN GUSTS...POOR VISIBILITIES AND SLICK ROADS. WEILAND
The national radar mosaic for the moment the first event began.
7 high wind. Local standard time, as filed.
WYDOT sensor at Arlington recorded sustained winds in excess of 40 mph and wind gusts greater than 58 mph throughout the period with a peak gust of 66 mph at 20/1301 MST.
WYDOT sensor at Vedauwoo recorded sustained winds in excess of 40 mph.
Sensor near Muddy Gap recorded wind gusts greater than 58 mph throughout the period with a peak gust of 72 mph 20/1450 MST.
WYDOT sensor at Bordeaux recorded sustained winds in excess of 40 mph and gusts greater than 58 mph throughout the period with a peak gust of 71 mph 20/1725 MST.
UP railroad at Como recorded sustained winds in excess of 40 mph.
WYDOT sensor at Vedauwoo measured sustained winds in excess of 40 mph.
UP railroad sensor at Emkay recorded sustained winds in excess of 40 mph and wind gusts greater than 58 mph throughout the period with a peak gust of 67 mph at 20/1615 MST.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2011Every state in 2011This day in weather historyWarnings in Wyoming, January 2011
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: 269226, 269201, 269116, 269108, 269186, 269204, 269222.