A strong pressure gradient produced high wind in the Green Mountains and Rattlesnake Hills. High wind in northern Johnson County produced a 76 mph gust at the Buffalo airport and toppled power lines and trees in town.
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 RIW wrote it up.
A strong pressure gradient produced high wind in the Green Mountains and Rattlesnake Hills. High wind in northern Johnson County produced a 76 mph gust at the Buffalo airport and toppled power lines and trees in town.
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 Feb 16, 4:01 PM MST, 7 hours 9 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 401 PM MST WED FEB 16 2011 .SHORT TERM...TONIGHT THROUGH SATURDAY INCOMING PACIFIC COLD FRONT AND TROUGH WILL BRING PERIODS OF MODERATE SNOWFALL TO THE WESTERN MOUNTAINS TONIGHT WITH UP TO 6 INCHES EXPECTED IN THE MOUNTAINS...UP TO 3 INCHES IN THE VALLEYS. AS THE FRONT APPROACHES...THE SURFACE WINDS WILL INCREASE WITH HIGH WINDS EXPECTED ACROSS THE GREEN AND RATTLESNAKE MOUNTAINS TONIGHT. DROPPED THE HIGH WIND WATCH FOR NATRONA COUNTY AS FORECAST WINDS THERE ARE NOW BELOW CRITERIA. WILL BE WINDY THOUGH WITH 35 MPH WINDS AT CASPER THIS AFTERNOON. SOME LIGHTNING IN WESTERN IDAHO ON THE BACK EDGE OF THE TROUGH. EXPECT THE AIR MASS TO STABILIZE BEFORE REACHING WYOMING. THERE WILL BE A BREAK IN THE SNOWFALL IN THE MORNING...THEN CONVECTIVE INSTABILITY WILL INCREASE IN THE AFTERNOON WITH SNOW INCREASING IN THE AFTERNOON. ANOTHER ONE TO TWO INCHES ARE EXPECTED. LITTLE PRECIPITATION IS EXPECTED EAST OF THE CONTINENTAL DIVIDE. SNOW WILL PICK UP THURSDAY NIGHT AND FRIDAY AHEAD OF ANOTHER PACIFIC TROUGH. THE PRECIPITATION WILL PICK UP SATURDAY. .LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY SIGNIFICANT MODEL DIFFERENCES CONTINUE TONIGHT. THEY CONTINUE TO STRUGGLE WITH THE MYRIAD OF SHORTWAVES ACROSS THE PACIFIC AND OVER TO SIBERIA. AT THE BEGINNING OF THE MEDIUM RANGE PERIOD...THE GFS CONTINUES TO KEEP THE DESERT SOUTHWEST LOW FURTHER SOUTH LIMITING THE SIGNIFICANT PRECIPITATION CHANCES OVER US. THE ECMWF CONTINUES TO HAVE A STRONGER LOW AND FURTHER NORTH WITH OVERRUNNING OCCURRING EAST OF THE DIVIDE SATURDAY NIGHT AND SUNDAY. STILL LEANING TOWARDS THE ECMWF TONIGHT WITH ITS SUPERIOR VERIFICATION THIS WINTER. THE NEXT SYSTEM AROUND THE MIDDLE OF NEXT WEEK IS ANOTHER CHALLENGE. THE GFS DEVELOPS THIS SYSTEM FROM A SHORTWAVE THAT SPINS OFF THE SIBERIAN LOW WHILE THE ECMWF DEVELOPS THIS SYSTEM FROM A DISTURBANCE OFF THE UPPER LOW CURRENTLY OVER ERN EUROPE AND NWRN RUSSIA. THE GFS IS THUS QUICKER BY A DAY IN BRINGING OUR TUESDAY...WEDNESDAY SYSTEM. WILL JUST KEEP SOME CHANCE POPS IN THE MOUNTAINS AND SLIGHT CHANCE ACROSS THE LOWER ELEVATIONS FOR NOW. WE WILL LIKELY NEED TO HIT THIS PERIOD MUCH HARDER BECAUSE IT DOES LOOK LIKE ITS JUST A MATTER OF TIMING. && .AVIATION... VERY WINDY CONDITIONS WILL PERSIST MOST AREAS TONIGHT INTO THURSDAY AS A TROUGH APPROACHES AND MOVES THROUGH OVERNIGHT. SOUTH TO SOUTHWEST WINDS AHEAD OF THE TROUGH WILL SHIFT TO THE WEST BEHIND THE TROUGH. LIGHT SNOW WILL FALL IN THE WEST TONIGHT...BEGINNING IN THE WEST BY 00Z. MVFR CIGS AND VSBYS ARE EXPECTED...WITH LCL IFR CIGS POSSIBLE. MVFR CIGS WILL PERSIST AFTER THE SNOW WINDS DOWN IN THE FAR WEST...WITH SOME SNOW SHOWERS EXPECTED THROUGH THE DAY. && .FIRE WEATHER... SNOW WILL SPREAD ACROSS THE WEST WITH UP TO 6 INCHES FALLING IN THE MOUNTAINS TONIGHT. AS A COLD FRONT MOVES INTO THE WEST...WINDS WILL INCREASE AND HIGH WINDS ARE EXPECTED IN CENTRAL WYOMING BEFORE FRONTAL PASSAGE. TEMPERATURES WILL COOL UP TO 20 DEGREES BEHIND THE COLD FRONT THURSDAY AND THURSDAY NIGHT. RELATIVE HUMIDITY WILL BE HIGHER ACROSS THE AREA. MIXING HEIGHTS WILL BE BELOW 3000 FEET THURSDAY AFTERNOON...WITH MOUNTAIN AREAS BELOW 1000 FEET...ESPECIALLY IN AREAS WITH SNOWFALL AND LOW CLOUDS. && .RIW WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING UNTIL 6 AM MST THURSDAY WYZ019. && SHORT TERM...C.BAKER LONG TERM...SKRBAC AVIATION...TWB FIRE WEATHER...C.BAKER
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 420 AM MST WED FEB 16 2011 WYZ001>020-022>030-171200- 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- 317 AM MST WED FEB 16 2011 ...HIGH WIND WARNING FOR THE GREEN MOUNTAINS AND RATTLESNAKE RANGE FOR THIS AFTERNOON THROUGH TONIGHT... ...HIGH WIND WATCH FOR NATRONA COUNTY INCLUDING CASPER FOR THIS AFTERNOON THROUGH TONIGHT... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT SOUTHWEST WINDS OF 30 TO 45 MPH WITH GUSTS TO 60 MPH ARE EXPECTED FROM THIS AFTERNOON THROUGH TONIGHT ACROSS THE GREEN MOUNTAINS AND RATTLESNAKE RANGE INCLUDING JEFFREY CITY. SOUTHWEST WINDS OF 30 TO 45 MPH WITH GUSTS TO 60 MPH ARE POSSIBLE FROM THIS AFTERNOON THROUGH TONIGHT ACROSS NATRONA COUNTY INCLUDING THE CITY OF CASPER. ALMOST ALL LOCATIONS IN WEST CENTRAL WYOMING WILL BE BREEZY TO WINDY BY WEDNESDAY AFTERNOON. 3 TO 7 INCHES OF SNOWFALL ACROSS WESTERN WYOMING IS EXPECTED FROM LATE THIS AFTERNOON THROUGH THURSDAY MORNING. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT WIND SPEEDS OF 40 MPH OR GREATER AND ANY SNOW AMOUNTS. THANK YOU. TEAM RIVERTON
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 644 PM MST WED FEB 16 2011 WYZ017-018-170500- LANDER FOOTHILLS-WIND RIVER BASIN- 644 PM MST WED FEB 16 2011 A GUSTY SOUTH TO SOUTHWEST WIND OF 25 TO 35 MPH WITH GUSTS FROM 40 TO 50 MPH WILL OCCUR ACROSS THE WIND RIVER BASIN THIS EVENING. THE WIND IS A RESULT OF A COLD FRONT APPROACHING FROM WESTERN WYOMING. THE FRONT WILL MOVE THROUGH THE BASIN AROUND MIDNIGHT. THEN THE WIND WILL TURN WEST AT 20 TO 30 MPH WITH GUSTS TO 40 MPH. MOTORISTS SHOULD BE PREPARED FOR SUDDEN WIND GUSTS. AR
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 817 PM MST WED FEB 16 2011 WYZ023-170500- STAR VALLEY- 817 PM MST WED FEB 16 2011 THE AREA OF MODERATE TO HEAVY SNOW WILL MOVE OUT OF THE STAR VALLEY BY 930 PM. A GUSTY WIND TO 30 MPH WILL OCCUR. THIS WILL LOWER VISIBILITY TO ONLY A FEW FEET AT TIMES. ANOTHER INCH OF SNOW IS POSSIBLE THROUGH 10 PM. MOTORISTS SHOULD EXPECT SLICK TO SNOW COVERED ROADS THIS EVENING. WYZ027-170500- SOUTH LINCOLN COUNTY- 817 PM MST WED FEB 16 2011 MODERATE TO HEAVY SNOW WILL CONTINUE THROUGH 930 PM. A GUSTY WEST OF 25 TO 35 MPH. THIS WILL LOWER VISIBILITY TO ONLY A FEW HUNDRED FEET AT TIMES. SNOWFALL OF UP TO 2 INCHES IS POSSIBLE WITH THIS BAND OF SNOW. THUNDER AND LIGHTNING IS ALSO POSSIBLE AROUND KEMMERER. MOTORISTS SHOULD EXPECT SLICK TO SNOW COVERED ROADS THIS EVENING. WYZ025-026-170500- UPPER GREEN RIVER BASIN-UPPER GREEN RIVER BASIN FOOTHILLS- 817 PM MST WED FEB 16 2011 MODERATE TO HEAVY SNOW WILL MOVE ACROSS THE VALLEY THROUGH 1000 PM. A GUSTY WIND OF 25 TO 35 MPH WITH GUSTS TO 45 MPH WILL OCCUR. THIS WILL LOWER VISIBILITY TO NEAR ZERO AT TIMES. SNOWFALL OF 1 TO 2 INCHES IS POSSIBLE WITH THIS BAND OF SNOW. MOTORISTS SHOULD EXPECT SLICK TO SNOW COVERED ROADS THIS EVENING. AR
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 839 PM MST WED FEB 16 2011 WYZ014-015-170500- WIND RIVER MOUNTAINS EAST-WIND RIVER MOUNTAINS WEST- 839 PM MST WED FEB 16 2011 HEAVY SNOWFALL WILL LIKELY BEGIN BY 915 PM ON SOUTH PASS. IN ADDITION...EXPECT GUSTY WEST WINDS OF 25 TO 35 MPH WITH GUSTS TO 50 MPH. THIS WILL LOWER VISIBILITY FROM ONLY A FEW HUNDRED FEET TO NEAR ZERO AT TIMES IN BLOWING AND FALLING SNOW. SNOWFALL OF UP TO 2 TO 3 INCHES IS POSSIBLE WITH THIS BAND OF SNOW. MOTORISTS DRIVING ON AREA HIGHWAYS INCLUDING HIGHWAY 28 SHOULD EXPECT SLICK TO SNOW COVERED ROADS ALONG WITH DRIFTING SNOW UNTIL ABOUT 10 PM THIS EVENING ALONG WITH VERY LOW VISIBILITY INCLUDING HIGHWAY 28. AR
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 853 PM MST WED FEB 16 2011 WYZ028-170600- ROCK SPRINGS AND GREEN RIVER- 853 PM MST WED FEB 16 2011 A BAND OF MODERATE TO HEAVY SNOW WILL MOVE INTO WESTERN SWEETWATER COUNTY AFTER 900 PM AND CONTINUE THROUGH MIDNIGHT. GREEN RIVER WILL IMPACTED AROUND 1000 PM AND ROCK SPRINGS AROUND 1100 PM. A GUSTY WEST WIND OF 25 TO 35 MPH WITH GUSTS TO 45 MPH WILL OCCUR WITH THE SNOW. THIS WILL CREATE VISIBILITY OF NEAR ZERO AT TIMES. MANY ROADS WILL BECOME SLICK AND SNOW COVERED. MOTORISTS SHOULD EXERCISE EXTREME CAUTION. AR
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 928 PM MST WED FEB 16 2011 WYZ017-018-170800- LANDER FOOTHILLS-WIND RIVER BASIN- 928 PM MST WED FEB 16 2011 A GUSTY SOUTH TO SOUTHWEST WIND OF 25 TO 35 MPH WITH GUSTS BETWEEN 40 TO 50 MPH WILL OCCUR ACROSS THE WIND RIVER BASIN THROUGH MIDNIGHT. THE WIND IS OCCURRING AHEAD OF A STRONG COLD FRONT WHICH WILL MOVE THROUGH THE BASIN AFTER MIDNIGHT. THE WIND WILL TURN TO THE WEST OR NORTHWEST AT 20 TO 30 MPH WITH GUSTS TO 40 MPH. RESIDENTS AND MOTORISTS SHOULD BE PREPARED FOR SUDDEN WIND GUSTS TONIGHT. AR
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 932 PM MST WED FEB 16 2011 WYZ028-170700- ROCK SPRINGS AND GREEN RIVER- 932 PM MST WED FEB 16 2011 A BAND OF MODERATE TO HEAVY SNOW WILL MOVE THROUGH WESTERN SWEETWATER COUNTY UNTIL MIDNIGHT. A GUSTY WEST WIND OF 25 TO 35 MPH WITH GUSTS TO 45 MPH WILL OCCUR WITH THE SNOW. SNOWFALL OF 1 TO 2 INCHES IS EXPECTED. VISIBILITY OF NEAR ZERO AT TIMES WILL OCCUR. MANY ROADS WILL BECOME SLICK AND SNOW COVERED. MOTORISTS SHOULD EXERCISE EXTREME CAUTION. AR
The national radar mosaic for the moment the first event began.
2 high wind. Local standard time, as filed.
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, February 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: 275280, 275282.