A late season winter storm brought snow to much of the region east of the Continental Divide with the highest amounts in the central mountains. Snowfall totals approached two feet on Casper Mountain and in the east slopes of the Wind River Range.
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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 RIW wrote it up.
A late season winter storm brought snow to much of the region east of the Continental Divide with the highest amounts in the central mountains. Snowfall totals approached two feet on Casper Mountain and in the east slopes of the Wind River Range. The highest amounts in the lower elevations included 9 inches at Jeffrey City and 6 inches at Wamsutter. In addition, wind gusts at times topping 40 mph combined with snow to cause road closures around much of the area, especially along Interstate 80. Snow drifts around Wamsutter were estimated at 4 feet in some locations.
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 Riverton, WY wrote its last area forecast discussion before the first event at May 11, 1:55 AM MST, 1 hour 35 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 255 AM MDT SUN MAY 11 2014 .SHORT TERM...TODAY THROUGH TUESDAY NIGHT A POTENT LOW PRESSURE SYSTEM CONTINUES TO SWING THROUGH THE GREAT BASIN EARLY THIS MORNING...IT WILL SLOWLY MOVE EAST THROUGH COLORADO THROUGH TONIGHT AND WILL OPEN UP IN THE PROCESS. A COLD FRONT WILL CONTINUE TO DROP SOUTH THIS MORNING...SPREADING COLDER AIR ACROSS THE STATE...MORE CONDUCIVE TO SNOW FALL. THIS STORM IS BEING POWERED BY A 130KT JET...THE BACK SIDE OF WHICH IS BRINGING WIDESPREAD DAMAGING WIND TO THE LAS VEGAS AREA WHILE THE FRONT SIDE IS CHURNING OUT AN IMPRESSIVE BAROCLINIC LEAF ON SATELLITE. MODELS WOULD SUGGEST THAT THE STRONGER FRONTOGENETIC AND QG FORCING WILL CLIP THE FAR SOUTHEASTERN ZONES TODAY BUT THE DEVELOPING UPSLOPE BEHIND THE COLD FRONT AND THE LEE CYCLOGENESIS EXPECTED TO TAKE PLACE IN NORTHERN COLORADO WILL ENCOURAGE SOME DECENT UPSLOPE SNOW TO CONTINUE ACROSS THE LANDER FOOTHILLS AND CASPER MOUNTAIN THROUGH MOST OF THE DAY AND INTO EARLY MONDAY MORNING...EXTENDED MOST OF THE ADVISORIES THROUGH 12Z MONDAY AND UPGRADED SOME OF THE MORE FAVORED AREAS UNDERNEATH THE STRONGEST FORCING AND WHERE THE STRONGEST WINDS WILL BE...TO WARNINGS. WHILE THE SNOW MAY HAVE A DIFFICULT TIME STICKING TO ROADS IN THESE AREAS...THE ADDED IMPACT OF THE STRONG NORTHEAST WIND TO TRAVEL AND THE EXPECTED IMPACT OF SIGNIFICANT SNOWFALL...STRONG WIND...AND TEMPERATURES BELOW FREEZING TO YOUNG TREES AND CATTLE PUSHED IT TO WARNING CRITERIA. SOME CLEARING WILL TAKE PLACE ACROSS THE WEST ON MONDAY WITH SOME SHOWERS EXPECTED IN THE AFTERNOON AS LAPSE RATES INCREASE TO ABOVE 7.5DEG/KM IN THE MOUNTAINS. WINDS REMAIN NORTHERLY SO SOME SHOWERS COULD COME OFF OF THE BRIDGERS AND THE WIND RIVERS INTO THE UPPER GREEN RIVER BASIN. OTHERWISE...SOME SHOWERS COULD LINGER ACROSS THE BIGHORNS AND INTO NATRONA COUNTY BUT ANY ACTIVITY IS EXPECTED TO BE MINOR IN COMPARISON TO WHAT IS EXPECTED OVER THE NEXT 24 HOURS. HIGH PRESSURE TAKES OVER AT THE SURFACE MONDAY NIGHT WITH SUBSIDENCE BEHIND THE EXITING UPPER LEVEL TROUGH. RESIDUAL MOISTURE AND LIGHTER SURFACE WINDS UNDERNEATH THE EXPANDING HIGH MAY ENCOURAGE SOME PATCHY FOG LATE MONDAY NIGHT INTO TUESDAY MORNING. TUESDAY WILL BE WARMER WITH A POTENTIALLY WELL TIMED SHORT WAVE MOVING THROUGH IN THE NORTHWEST FLOW IN THE AFTERNOON...DELIVERING A CHANCE FOR SHOWERS...ESPECIALLY ACROSS THE NORTHERN MOUNTAINS AND FOOTHILLS. .LONG TERM...WEDNESDAY THROUGH SUNDAY GFS AND ECMWF MODELS ARE KEEPING THEIR DIFFERENT SOLUTIONS WED THROUGH FRIDAY. THE DIFFERENCES CENTER ON THE SHARPNESS OF A NW FLOW ALOFT OVER THE REGION. THE GFS MAINTAINS A WARMER SCENARIO AND DRIER SITUATION. THE GFS DOES HAVE DAILY CONVECTION FORMING OVER THE MOUNTAINS WITH ISOLATED ACTIVITY DRIFTING SOUTHEAST OVER THE LOWER ELEVATIONS. THE ECMWF MODEL IS COOLER AND WETTER WITH MORE COVERAGE OF DAILY CONVECTION WED THROUGH FRIDAY. BOTH MODELS DO KEEP THE SOUTHWEST ZONES MOSTLY DRY WITH ISOLATED ACTIVITY AT BEST. STILL WISH TO LEAN TOWARD THE ECMWF SOLUTION AND KEEP A GRADUAL WARMING OF HIGHS WED THROUGH FRIDAY AND A LITTLE MORE COVERAGE OF SHOWERS AND STORMS. WITH RESPECT TO SATURDAY AND NEXT SUNDAY THE TRANSITION TO A WESTERLY FLOW ON SATURDAY AND THEN A SOUTHWEST FLOW NEXT SUNDAY IS ALSO INTERESTING. BOTH THE GFS AND ECMWF HAVE COME MORE INTO LINE WITH EACH OTHER TONIGHT. THE WARMER AIR ARRIVES ON SATURDAY WITH NEXT SUNDAY BEING ABOUT THE SAME FOR MOST. IN NW AND FAR NORTH WY A FRONTAL BOUNDARY SLIDES INTO THAT AREA SUNDAY BRINGING COOLER AIR PER BOTH LONG RANGE MODELS. FOR NOW WILL GO DRY SATURDAY AND NEXT SUNDAY IN THE CENTRAL AND SOUTH. ISOLATED SHOWER AND THUNDERSTORM ACTIVITY OVER THE NORTH ZONES BOTH DAYS. SNOWMELT ISSUES WOULD BE MORE OF A CONCERN LATE IN THE WEEK OVER THE WESTERN MOUNTAINS...THEN FOR ALL MOUNTAINS SATURDAY AND SUNDAY DUE TO THE EXPECTED WARMER HIGHS. && .AVIATION.../12Z ISSUANCE/ A MAJOR SPRING SNOWSTORM WILL BE ONGOING ACROSS MUCH OF THE AREA...WITH THE EXCEPTION ACROSS THE FAR WEST/NORTHWEST WHERE IMPACTS WILL BE MUCH LESS. WIDESPREAD MVFR/IFR CEILINGS WILL OCCUR THROUGH MUCH OF THE DAY EAST OF THE DIVIDE AS WELL AS SOUTHERN LINCOLN AND ALL OF SWEETWATER COUNTIES. PERSISTENT IFR TO LIFR IN SNOW AND BLOWING SNOW ARE EXPECTED ALONG AND SOUTHEAST OF A LINE FROM KRKS-KLND-KCPR FOR MUCH OF THE DAY. VERY STRONG NORTHEAST WINDS WILL IMPACT AREAS BETWEEN KRKS-KCPR. CONDITIONS ARE EXPECTED TO SLOWLY IMPROVE THIS EVENING...BUT SOME AREAS WILL BE STUBBORN TO IMPROVE TO LOW VFR CEILINGS. ACROSS THE WEST/NORTHWEST...INCLUDING KJAC...KBPI...KPNA...MAINLY VFR CONDITIONS ARE EXPECTED WITH POSSIBLY SOME SHOWER ACTIVITY. KBPI COULD BE A SURPRISE...BUT CONFIDENCE IS FAIRLY HIGH THAT KJAC AND KPNA WILL HAVE LITTLE IMPACT FROM THIS SYSTEM OTHER THAN BREEZY WINDS. && .FIRE WEATHER... WIDESPREAD SNOW WITH 3 TO 6 INCHES ACCUMULATION IN THE LOWER ELEVATIONS OF FREMONT...NATRONA AND SWEETWATER COUNTIES WITH 5 TO 15 INCHES IN THE WIND RIVER MOUNTAINS AND CASPER MOUNTAIN. SNOWFALL AMOUNTS ARE EXPECTED TO BE LESS ACROSS THE NORTH AND WEST BUT MOST OF THE AREA WILL RECEIVE SNOWFALL. A WARMING TREND IS EXPECTED AFTER MONDAY WITH OCCASIONAL SHOWERS EXPECTED THROUGH AT LEAST MID WEEK. && .RIW WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 6 AM MDT MONDAY WYZ019-022-030. WINTER WEATHER ADVISORY UNTIL 6 AM MDT MONDAY WYZ015-018-020. WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT WYZ028-029. && SHORT TERM...ALLEN LONG TERM...AR AVIATION...WM FIRE WEATHER...ALLEN
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 300 AM MDT SUN MAY 11 2014 WYZ001>020-022>030-121200- ABSAROKA MOUNTAINS-BIGHORN MOUNTAINS SOUTHEAST- BIGHORN MOUNTAINS WEST-CASPER MOUNTAIN-CODY FOOTHILLS- EAST SWEETWATER COUNTY-FLAMING GORGE- GREEN MOUNTAINS AND RATTLESNAKE RANGE-JACKSON HOLE-LANDER FOOTHILLS- NATRONA COUNTY LOWER ELEVATIONS-NORTH BIG HORN BASIN- NORTHEAST JOHNSON COUNTY-OWL CREEK AND BRIDGER MOUNTAINS- ROCK SPRINGS AND GREEN RIVER-SALT RIVER AND WYOMING RANGES- SOUTH LINCOLN COUNTY-SOUTHEAST BIG HORN BASIN- SOUTHEAST JOHNSON COUNTY-SOUTHWEST BIG HORN BASIN-STAR VALLEY- TETON AND GROS VENTRE MOUNTAINS-UPPER GREEN RIVER BASIN- UPPER GREEN RIVER BASIN FOOTHILLS-UPPER WIND RIVER BASIN- WIND RIVER BASIN-WIND RIVER MOUNTAINS EAST-WIND RIVER MOUNTAINS WEST- YELLOWSTONE NATIONAL PARK- 300 AM MDT SUN MAY 11 2014 ...WINTER WEATHER ADVISORIES AND WINTER STORM WARNINGS THROUGH EARLY MONDAY MORNING FOR NATRONA...FREMONT AND SWEETWATER COUNTIES... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT SIGNIFICANT SNOWFALL ALONG AND SOUTHEAST OF A ROCK SPRINGS...LANDER TO CASPER LINE. HOWEVER OTHER AREAS WILL SEE RAIN CHANGING TO SNOW EARLY...AND COULD HAVE ROADS BECOME SLICK AND HAZARDOUS. STRONG NORTHEAST WIND WILL OCCUR TODAY ACROSS MUCH OF THE AREA...THE STRONG CROSS WIND ALONG INTERSTATE 80 IS EXPECTED TO ADD TO THE IMPACT OF THE OCCASIONALLY HEAVY SNOW TODAY. EXPECT TRAVEL DIFFICULTIES IN THE WARNED AREAS. IN ADDITION...THE COLDER TEMPERATURES...SNOW...HIGH HUMIDITY AND PERSISTENT NORTH WIND COULD BE DIFFICULT FOR YOUNG LIVESTOCK AND NEW VEGETATION. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY WEDNESDAY THROUGH FRIDAY...ISOLATED AFTERNOON AND EARLY EVENING THUNDERSTORMS WILL OCCUR EACH DAY. SOME STORMS WILL PRODUCE SMALL HAIL. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE URGED TO REPORT SNOWFALL AMOUNTS AND WIND GUSTS OVER 50 MPH...THANK YOU. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
4 winter storm. Local standard time, as filed.
A trained spotter measured 6 inches of snow in Wamsutter.
Heavy snow fell across the eastern slopes of the Wind River Range. Some the higher amounts included 22 inches at Townsend Creek, 19 inches at Hobbs Park and 18 inches at Hobbs Park.
Trained spotters measured 20 to 23 inches of new snow on Casper Mountain.
The cooperative observer at Jeffrey City reported 9 inches of snow.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2014Every state in 2014This day in weather historyWarnings in Wyoming, May 2014
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: 511353, 511359, 511342, 511347.