A strong thunderstorm generated gusty outflow wind at Rock Springs-Sweetwater County Airport.
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The episode as NWS RIW wrote it up.
A strong thunderstorm generated gusty outflow wind at Rock Springs-Sweetwater County Airport.
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 Aug 29, 2:22 AM MST, 11 hours 37 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 322 AM MDT SUN AUG 29 2010 .SHORT TERM...TODAY THROUGH TUESDAY NIGHT HIGHLY AMPLIFIED TROUGH OVER THE WESTERN CONUS THIS MORNING WITH AN UNSEASONABLY STRONG 100+KT JET SURGING NORTHEAST OVER UTAH...EASTERN IDAHO AND WESTERN WYOMING INTO MONTANA. THERE IS SOME WEAK LINGERING CONVECTION OVER WESTERN AND NORTHERN WYOMING THIS MORNING. A COLD FRONT MOVED INTO NORTHERN WYOMING LATE YESTERDAY AFTERNOON AND HAS PUSHED INTO THE NORTHERN WIND RIVER BASIN. THE JET IS FORECAST TO STRENGTHEN TODAY WITH SOUTHWEST FLOW INCREASING AT THE SURFACE...PUSHING THE FRONT NORTH. FIRE WEATHER CONCERN TODAY...MODELS HAVE BEEN DRYING OUT THE LOW LEVELS OVER WIND RIVER BASIN AND NATRONA COUNTY WITH RH'S IN THE LOWER TEENS. STILL SOME RELATIVELY HIGH DEWPOINTS UPSTREAM SO NOT INCLINED TO LOWER RH'S THAT MUCH SO WILL MENTION INCREASED FIRE DANGER OVER THESE AREAS. ON TO PRECIP...BEST CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE OVER THE WEST WHERE THE JET CORE WILL BE OVERHEAD. SHOULD SEE ISOLATED TO SCATTERED STORMS OVER THE CENTRAL AND EAST AS WELL. GUSTY OUTFLOWS...LIGHTNING AND SMALL HAIL WILL BE THE PRIMARY THREATS. COULD SEE A SEVERE GUST OR TWO OVER THE SOUTHWEST AND CENTRAL. TROUGH SLOWLY PROGRESSES EASTWARD OVERNIGHT TONIGHT WITH COLD AIR MOVING INTO THE WEST...WITH H7 TEMPS FALLING TO -1C OVER THE NORTHWEST BY 18Z MONDAY. COULD SEE BAROCLINIC LEAF SET UP OVER THIS AREA DURING THE MORNING AND AFTERNOON WITH SNOW LIKELY ABOVE 8000 FEET. COULD SEE ACCUMULATIONS OF 1 TO 3 INCHES OF SNOW POSSIBLE ABOVE THIS ELEVATION. GFS MUCH DRIER THAN NAM...BASED ON HOW WET ITS BEEN HAVE SIDED MORE ON THE NAM SOLUTION. SCATTED SHOWERS AND THUNDERSTORMS EXPECTED EAST OF THE DIVIDE UNDER DIFLUENT FLOW ALOFT. COLD FRONT MOVES THROUGH AREAS EAST OF THE DIVIDE THIS EVENING...WASHING OUT MONDAY MORNING AS SOUTHWEST WINDS PICK UP AGAIN. TROUGH AXIS MOVES THROUGH MONDAY AFTERNOON AND EVENING...WITH A SECONDARY COLD FRONT MOVING ACROSS THE AREA. TRANSITORY RIDGE BUILDS IN BEHIND THE TROUGH...THOUGH THE NEXT TROUGH RAPIDLY APPROACHES TUESDAY IN THE NEAR ZONAL FLOW. THIS WILL BRING THE CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE NORTH. WILL ALSO SEE SOME SOUTHWEST TO WEST WINDS AGAIN ACROSS THE AREA. TEMPERATURES WILL BE SLOW TO WARM. .LONG TERM...WEDNESDAY THROUGH SUNDAY UNSETTLED AND COOL WEATHER WILL REMAIN OVER THE NORTH WEDNESDAY WITH A CHANCE OF SHOWERS AND THUNDERSTORMS...SNOW SHOWERS IN THE NORTHERN MOUNTAINS ABOVE 9000 FEET. MOSTLY DRY AND WARMER WEATHER PREVAILS THURSDAY WITH SLIGHT CHANCES OF LATE DAY THUNDERSTORMS ACROSS THE NORTHWEST AND SOUTH ON FRIDAY. SLIGHT CHANCES OF SHOWERS AND THUNDERSTORMS CONTINUE ACROSS THE NORTH NEXT WEEKEND ALONG WITH NEAR NORMAL TEMPERATURES. MEDIUM-RANGE MODELS SHOW SOME SPREAD WITH UPPER TROUGH PASSAGE ON WEDNESDAY WITH THE GFS ON THE DEEPER END OF SOLUTIONS...THE GEM AND ECMWF FLATTER AND MORE PROGRESSIVE. MODELS GENERALLY AGREE ON BUILDING UPPER RIDGE IN THURSDAY. AFTERWARDS MODEL SPREAD INCREASES THE GEM AND ECMWF SHOWING DEEPER COLDER TROUGH DIGGING ACROSS SOUTHERN BRITISH COLUMBIA INTO THE NW U.S. NEXT WEEKEND WHILE THE GFS IS MUCH FLATTER WITH THIS FLOW DUE TO MORE PROGRESSIVE...LESS AMPLIFIED UPSTREAM FLOW OVER THE PACIFIC. FORECAST WEIGHTED TOWARD THE ECMWF AND GEM SOLUTIONS WHICH BEST REFLECT THE LATE AUGUST PATTERN. STRONG JET STREAK AND ASSOCIATED SHORTWAVE ON WEST END OF ALEUTIANS THIS MORNING TO MOVE ACROSS THE AREA WEDNESDAY WITH PRECIPITATION CHANCES CONFINED TO THE NORTHERN THIRD OF THE CWA. ASSOCIATED COLD FRONT WILL PLUNGE SOUTH DURING THE DAY WEDNESDAY KEEPING TEMPERATURES ON THE COOL SIDE...IN THE UPPER 60S AND 70S MOST LOWER ELEVATIONS. BUILDING UPPER RIDGE WILL PUSH PRECIPITATION EAST OF AREA BY 12Z THURSDAY. ECMWF MAY BE TOO STRONG WITH A SHORTWAVE ACROSS SOUTH CENTRAL CANADA SATURDAY MORNING. UPPER TROUGH DIGS ALONG WEST COAST SUNDAY WITH SW FLOW OVER WYOMING ALONG WITH WEAK EMBEDDED SHORTWAVES AND CHANCES FOR LATE DAY CONVECTION MAINLY ACROSS THE NORTH. && .AVIATION... UNSETTLED WEATHER WILL OCCUR TODAY INTO THE EVENING AS A STORM SYSTEM OVER THE GREAT BASIN MOVES CLOSER TO WY. SCATTERED SHOWERS AND STORMS WILL OCCUR OVER THE WEST TODAY INTO THIS EVENING. VFR CONDITIONS WILL PREVAIL...HOWEVER MVFR CONDITIONS WILL OCCUR WHERE STRONGER STORMS DEVELOP. IN THE CENTRAL VFR CONDITIONS WILL PREVAIL WITH ISOLATED SHOWERS AND THUNDERSTORMS TODAY AND THIS EVENING. WINDY CONDITIONS WILL OCCUR FROM KRKS TO KLND TO KRIW TO KCPR AFTER 15Z WITH SPEEDS OF 20 TO 30 KNOTS WITH GUSTS TO 40 KNOTS DURING THE DAY. && .FIRE WEATHER... A TROUGH WILL CONTINUE TO APPROACH WYOMING TODAY WITH A SOUTHWEST FLOW INCREASING OVERHEAD. SOUTHWEST WINDS WILL INCREASE ACROSS MUCH OF THE AREA TODAY WITH RH'S OVER COME CENTRAL ZONES POSSIBLY APPROACHING THE MID TEENS. NOT EXPECTING WIDESPREAD OCCURRENCE OF THIS AT THIS TIME SO WILL NOT ISSUE ANY WATCH OR WARNING. SHOWERS AND THUNDERSTORMS WILL DEVELOP TODAY OVER THE WEST...WITH ISOLATED TO SCATTERED ACTIVITY EXPECTED ELSEWHERE. GUSTY WINDS...LIGHTNING AND SMALL HAIL WILL BE THE PRIMARY THREAT...THOUGH SOME HEAVY RAINFALL IS POSSIBLE AS WELL. TEMPERATURES WILL BE COOLER TODAY. A STRONG COLD FRONT WILL MOVE THROUGH OVERNIGHT WITH SNOW LEVELS FALLING TO AROUND 8000 FEET OVER NORTHWEST WYOMING BY MONDAY MORNING. ONE TO THREE INCHES OF SNOWFALL IS POSSIBLE THERE DURING THE DAY MONDAY. RAIN IS EXPECTED BELOW. A FEW THUNDERSTORMS ARE EXPECTED ACROSS THE AREA MONDAY AS WELL. SOUTHWEST TO WEST WINDS WILL CONTINUE AS WELL. WEST FLOW WILL BE OVERHEAD TUESDAY WITH ISOLATED THUNDERSTORMS POSSIBLE ACROSS THE NORTH. && .RIW WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...TWB LONG TERM...AEM AVIATION...AR FIRE WEATHER...TWB
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 500 AM MDT SUN AUG 29 2010 WYZ001>020-022>030-301100- 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- 500 AM MDT SUN AUG 29 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT SHOWERS AND THUNDERSTORMS WILL CONTINUE AROUND THE AREA TODAY AND TONIGHT. THEY WILL BE MOST NUMEROUS OVER THE WEST...AND SCATTERED ELSEWHERE. A FEW OF THE STORMS MAY CONTAIN SMALL HAIL...WIND GUSTS OVER 40 MPH...HEAVY RAIN AND FREQUENT LIGHTNING. TAKE SHELTER IF STORMS APPROACH YOUR AREA. A FEW STORMS WILL LINGER INTO THE EARLY MORNING HOURS. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY COLDER AIR MOVES IN MONDAY MORNING...WITH ONE TO THREE INCHES OF SNOWFALL POSSIBLE OVER THE NORTHWEST MOUNTAINS ABOVE 8000 FEET. ISOLATED TO SCATTERED THUNDERSTORMS ARE POSSIBLE ACROSS THE AREA MONDAY. ISOLATED THUNDERSTORMS ARE POSSIBLE TUESDAY AFTERNOON ACROSS THE NORTH. A COLD FRONT PASSAGE ON WEDNESDAY WILL BRING THE POSSIBILITY OF SNOWFALL WITH LIGHT ACCUMULATIONS ACROSS YELLOWSTONE NATIONAL PARK AND THE NORTHERN MOUNTAINS WEDNESDAY AND WEDNESDAY NIGHT. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT HAIL...WIND GUSTS OVER 40 MPH...ANY HAIL AND FLOODING. THANK YOU. TEAM RIVERTON
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 1248 PM MDT SUN AUG 29 2010 WYZ001-291945- YELLOWSTONE NATIONAL PARK- 1248 PM MDT SUN AUG 29 2010 SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP ACROSS YELLOWSTONE NATIONAL PARK THIS AFTERNOON. CURRENT ACTIVITY IS PRIMARILY NOTED ACROSS THE NORTHEASTERN QUADRANT OF THE PARK...THOUGH STORMS CONTINUE TO BUILD TO THE SOUTHWEST. THESE SHOWERS WILL PRODUCE LIGHTNING...AND MAY PRODUCE GUSTY WIND TO 40 MPH AND SMALL HAIL. THOSE ENJOYING OUTDOOR ACTIVITIES SHOULD STRIVE TO FIND AN INDOOR SHELTER DURING STORM ACTIVITY. SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO REMAIN PRESENT ACROSS THE PARK FOR THE REMAINDER OF THE AFTERNOON...THOUGH SECTIONS OF THE PARK WILL SEE PERIODS OF CLEARING CONDITIONS. BRANHAM
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 215 PM MDT SUN AUG 29 2010 WYZ002>004-292045- ABSAROKA MOUNTAINS WY-CODY FOOTHILLS WY-NORTH BIG HORN BASIN WY- 215 PM MDT SUN AUG 29 2010 ...SIGNIFICANT WEATHER ADVISORY FOR WESTERN BIG HORN COUNTY IN NORTH CENTRAL WYOMING...AND EASTERN PARK COUNTY IN NORTHWEST WYOMING UNTIL 245 PM MDT... AT 212 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR STATE HWY 120 MILE MARKER 80...OR NEAR CODY...MOVING NORTHEAST AT 10 MPH. HAIL RANGING FROM THE SIZE OF PEAS TO DIMES IS EXPECTED WITH THIS STORM...ALONG WITH FREQUENT DANGEROUS LIGHTNING. THIS STORM WILL BE NEAR... HWY 14/16/20 MILE MARKER 50 AROUND 225 PM MDT. STATE HWY 120 MILE MARKER 80 AND CODY AROUND 230 PM MDT. HWY 14/16/20 MILE MARKER 60 AROUND 240 PM MDT. U.S. HWY 14A MILE MARKER 10 AROUND 245 PM MDT. IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A STURDY BUILDING. REPORT HAZARDOUS WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN RIVERTON AT 1-800-211-1448. LAT...LON 4483 10906 4473 10844 4433 10901 4444 10922 TIME...MOT...LOC 2014Z 215DEG 11KT 4446 10904 BRANHAM
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 256 PM MDT SUN AUG 29 2010 WYZ003-004-292130- CODY FOOTHILLS WY-NORTH BIG HORN BASIN WY- 256 PM MDT SUN AUG 29 2010 ...SIGNIFICANT WEATHER ADVISORY FOR WESTERN BIG HORN COUNTY IN NORTH CENTRAL WYOMING...AND EASTERN PARK COUNTY IN NORTHWEST WYOMING UNTIL 330 PM MDT... AT 254 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 5 MILES NORTHWEST OF HWY 14/16/20 MILE MARKER 70...OR 13 MILES EAST OF CODY...MOVING EAST AT 15 MPH. HAIL RANGING FROM PENNY TO DIME SIZED IS EXPECTED WITH THIS STORM. THIS STORM WILL BE NEAR... RURAL EASTERN PARK COUNTY THROUGH 330 PM MDT RURAL WESTERN BIG HORN COUNTY THROUGH 330 PM MDT REPORT HAZARDOUS WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN RIVERTON AT 1-800-211-1448. LAT...LON 4483 10851 4440 10838 4441 10886 4458 10896 TIME...MOT...LOC 2056Z 248DEG 13KT 4453 10879 BRANHAM
The Riverton/Lander radar (KRIW), 170 km away, was scanning. The volume nearest the first event began at 21:00 UTC.
1 thunderstorm wind. Local standard time, as filed.
A thunderstorm wind gust of 63 mph was measured by ASOS at Rock Springs-Sweetwater County Airport.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2010Every state in 2010This day in weather historyWarnings in Wyoming, August 2010
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: 251859.