Melting of a substantial late-season snowpack caused mud and debris to flow across the Upper Hoback River Road in far west Sublette County. The flow occurred at mile 14 of the road and was several feet deep.
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The episode as NWS RIW wrote it up.
Melting of a substantial late-season snowpack caused mud and debris to flow across the Upper Hoback River Road in far west Sublette County. The flow occurred at mile 14 of the road and was several feet deep. Large trees were toppled and downed timber was brought down the mountainside by the slide.
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 Jun 14, 2:29 AM MST, 11 hours 31 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 329 AM MDT TUE JUN 14 2011 .SHORT TERM...TODAY THROUGH THURSDAY NIGHT A WEAK COLD FRONT WILL CONTINUE TO BE THE FOCUS FOR SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE NORTH THIS MORNING...PROMPTING A SMALL STREAM FLOOD ADVISORY FOR NORTHERN TETON PARK AND SOUTHWESTERN YELLOWSTONE DUE TO PERSISTENT RAINFALL. SOME LOCATIONS HAVE RECORDED AN INCH OF RAIN DURING THE EVENING. COOLER AIR WILL FILTER IN BEHIND THE FRONT BUT THERE WILL STILL BE ENOUGH INSTABILITY TO KEEP SHOWERS AND THUNDERSTORMS IN THE FORECAST AS AN UPPER TROUGH SWINGS THROUGH MONTANA...IN ADDITION TO SOME JET SUPPORT. RIDGING APPROACHES FROM THE WEST THIS EVENING...GRADUALLY INCREASING THE PRESSURE GRADIENT TODAY...WINDS WILL REMAIN ELEVATED THROUGH WEDNESDAY. TEMPERATURES WILL RISE ON WEDNESDAY AS THE RIDGE TAKES OVER. TEMPERATURES COULD CLIMB INTO THE 80S EAST OF THE DIVIDE AND INTO THE 40S AND 50S ABOVE 9000 FEET. THE NEXT SYSTEM APPROACHES ON THURSDAY...BRINGING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS AS THE RIDGE BREAKS DOWN. SEVERAL SHORT WAVES WILL EJECT AHEAD OF THE MAIN TROUGH AS IT BUMPS AGAINST THE RIDGE OVER THE MIDWEST. TIMING THESE SHORT WAVES WILL BE DIFFICULT BUT POPS WERE INCREASED ACROSS THE AREA ON THURSDAY TO ACCOUNT FOR THE APPROACHING SYSTEM. .LONG TERM...FRIDAY THROUGH TUESDAY LONGWAVE TROUGH PERSISTS ACROSS THE INTER-MOUNTAIN WEST THROUGH EARLY NEXT WEEK. SIGNIFICANT SNOWFALL IS QUITE POSSIBLE IN THE WESTERN MOUNTAINS...ESPECIALLY THE NORTHWEST ON SUNDAY WHEN A COLD LATE SPRING...AS LATE AS YOU CAN GET...MOVES INTO THE AREA WITH H7 TEMPERATURES BELOW 0C. OTHERWISE...IT WILL BE UNSETTLED WITH BELOW NORMAL TEMPERATURES THROUGH MOST OF THE MEDIUM RANGE PERIOD... ESPECIALLY THE LATE IN THE WEEKEND THROUGH EARLY NEXT WEEK. MODELS ARE STRUGGLING WITH THE DETAILS BUT NOT THE OVERALL TROUGHINESS THAT WILL PERSIST THROUGH THE PERIOD. THURSDAY SYSTEM WILL LINGER INTO FRIDAY BEFORE THE NEXT MORE SIGNIFICANT TROUGH DEVELOPS TO OUR WEST OVER THE WEEKEND AND THEN SWINGS ACROSS THE AREA SUNDAY INTO SUNDAY NIGHT. SCATTERED SHOWERS AND THUNDERSTORMS WILL LINGER INTO FRIDAY AS TROUGH AXIS FROM OUR THURSDAY SYSTEM PASSES THROUGH. COULD SEE SOME ACTIVE THUNDERSTORMS WITH THIS THERMAL TROUGH. ON SATURDAY...THE WEST WILL AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS TODAY AHEAD OF OUR BIG SYSTEM. THE ECMWF HAS A WEAKER TROUGH FURTHER SOUTH INCREASING THE ODDS OF THUNDERSTORMS IN OUR SERN ZONES. LEANING TOWARDS THE WEST FOR THE HIGHEST POPS BUT COULD ALSO SEE STORMS FIRING OFF THE UINTAS AND RACING NORTHEAST INTO SWEETWATER COUNTY. THE COLD TROUGH THEN MOVES IN SATURDAY NIGHT AND SUNDAY WITH SNOW DEVELOPING IN THE WESTERN MOUNTAINS AS H7 TEMPERATURES WILL LIKELY DROP BELOW 0C. SNOW LEVEL IS STILL UNCERTAIN THIS FAR OUT BUT COULD EASILY SEE SNOW DOWN TO 8K FEET AND POSSIBLY LOWER. SIGNIFICANT SNOWFALL IS A DISTINCT POSSIBILITY IN THE WESTERN MOUNTAINS...ESPECIALLY THE NORTHWEST INCLUDING YELLOWSTONE NATIONAL PARK. THE ECMWF IS MUCH FURTHER SOUTH WITH THIS SYSTEM WHICH WOULD INCREASE THE ODDS OF MORE SNOW FURTHER SOUTH...OR AT LEAST AT A LOWER ELEVATION. NOT QUITE READY TO BUY INTO A SYSTEM THIS STRONG AND FAR SOUTH BUT BASED ON THIS SPRING SO FAR...IT'S POSSIBLE. STRONG TO SEVERE STORMS ARE VERY POSSIBLE WITH THIS SCENARIO...ESPECIALLY EAST OF THE DIVIDE ON SUNDAY. WRAPAROUND SHOWERS AND MOUNTAIN SNOW WILL CONTINUE ON MONDAY MAINLY ACROSS THE NORTH. TEMPERATURES WILL REMAIN WELL BELOW NORMAL THROUGH TUESDAY AS A COOL NORTHWEST FLOW WITH EVEN SOME SHOWERS LINGERING ACROSS THE NORTHERN MOUNTAINS AND EVEN THE FAR NORTH LOWER ELEVATIONS. NO HINT OF AN EXTENDED WARM- UP UNTIL THE SECOND HALF OF NEXT WEEK. EVEN IF THE LAST WEEK OF JUNE TURNS OUT TO BE VERY WARM...JUNE WILL LIKELY GO DOWN AS ONE OF THE COOLEST IN RECORDED HISTORY. FLOODING CONCERNS MAY ELEVATE SIGNIFICANTLY WITH THIS PATTERN BUT NOT BEFORE THE LAST WEEK OF JUNE. HOWEVER...THE THREAT OF MORE THUNDERSTORMS AND HEAVY RAIN WILL PERSIST JUST NOT WITH VERY WARM TEMPERATURES. && .AVIATION... A SLOW MOVING SHORTWAVE CONTINUES TO GENERATE -SHRA/-TSRA ACROSS THE NORTHWEST QUARTER OF THE STATE EARLY THIS MORNING. SUBSIDENCE BEHIND THIS WAVE WILL LEAD TO LESS CLOUD COVER AND CONVECTION ACROSS THE SOUTHERN TWO-THIRDS OF THE FORECAST AREA ON TUESDAY. VFR CEILINGS AND VISIBILITIES EXPECTED AT ALL TERMINALS ON TUESDAY. SHORTWAVE SPINNING JUST NORTH OF THE IDAHO PANHANDLE EARLY THIS MORNING WILL DROP ACROSS SOUTHERN MONTANA TODAY. LINGERING MID-LEVEL MOISTURE COUPLED WITH DECENT JET DYNAMICS AND LIFT WITH PASSING SHORTWAVE WILL LEAD TO CONVECTION AT KCOD AND KWRL TUESDAY AFTERNOON. ONLY OTHER TERMINAL WITH MARGINAL INSTABILITY WILL BE KCPR. GUSTY OUTFLOW WIND LIKELY TO BE THE MAIN HAZARD WITH -SHRA/-TSRA WITH GUSTS OF 35-40KTS POSSIBLE LATER THIS AFTERNOON. SURFACE PRESSURE GRADIENT WILL TIGHTEN TODAY AS SHORTWAVE PASSES TO THE NORTH. SURFACE WINDS OF 15-25KTS WILL BE COMMON AT MOST TERMINALS. ANY MOUNTAIN TOP OBSCURATIONS WILL BE GENERALLY CONFINED TO AREAS ALONG AND NORTH OF A KJAC-KBYG LINE. && .HYDROLOGY... A NEW SMALL STREAM FLOOD ADVISORY HAS BEEN ISSUED FOR PORTIONS OF TETON AND YELLOWSTONE PARKS. THE SNAKE RIVER AT FLAGG RANCH IS RESPONDING TO PERSISTENT RAINFALL OVERNIGHT...IT IS CURRENTLY JUST SHY OF ACTION STAGE AND CLIMBING. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE ACROSS THE NORTH THROUGH MUCH OF THE DAY BEFORE A WARM RIDGE BUILDS IN TONIGHT. TEMPERATURES WILL BE RISING INTO THE 50S AND 60S IN THE WEST ON WEDNESDAY AS THE RIDGE BUILDS...BUT IT WILL BE SHORT LIVED AS ANOTHER SYSTEM WILL COOL TEMPERATURES AGAIN ON THURSDAY. A FLOOD WATCH CONTINUES FOR THE NORTH PLATTE AT CASPER AS RESERVOIR RELEASES REMAIN STEADY. THE FLOOD WARNING FOR NORTHWEST LINCOLN COUNTY CONTINUES AS MINOR FLOODING OF THE SALT RIVER IS EXPECTED TO CONTINUE AT LEAST INTO THURSDAY MORNING. && .RIW WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH THROUGH TUESDAY MORNING WYZ020. && SHORT TERM...ALLEN LONG TERM...SKRBAC AVIATION...CNJ HYDROLOGY...ALLEN
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 500 AM MDT TUE JUN 14 2011 WYZ001>020-022>030-151100- 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 TUE JUN 14 2011 ...FLOOD WATCHES...WARNINGS AND ADVISORIES CONTINUE FOR PORTIONS OF CENTRAL AND WESTERN WYOMING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT CREEKS AND RIVERS WILL REMAIN HIGH AND SWIFT OVER MUCH OF THE AREA. THIS ESPECIALLY WILL OCCUR WEST OF THE CONTINENTAL DIVIDE. PLEASE SEE THE LATEST HYDROLOGICAL PRODUCTS FOR THE MOST CURRENT RIVER AND STREAM INFORMATION. OTHERWISE...WIDELY SCATTERED THUNDERSTORMS ARE POSSIBLE TODAY... ESPECIALLY IN THE NORTH. THE STORMS COULD CONTAIN FREQUENT LIGHTNING...STRONG GUSTY WINDS...HAIL AND BRIEF HEAVY DOWNPOURS. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY AN ACTIVE LATE SPRING PATTERN WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE AREA THURSDAY INTO FRIDAY. SOME OF THESE THUNDERSTORMS MAY BE QUITE STRONG. AN EVEN STRONGER AND COLDER STORMS SYSTEM WILL TAKE SHAPE LATE IN THE WEEKEND WITH SIGNIFICANT SNOWFALL QUITE POSSIBLE IN THE WESTERN MOUNTAINS...ESPECIALLY THE NORTHWEST MOUNTAINS INCLUDING YELLOWSTONE NATIONAL PARK. STRONG TO SEVERE THUNDERSTORMS MAY DEVELOP ON SUNDAY EAST OF THE DIVIDE. CREEKS AND RIVERS WILL CONTINUE TO RUN HIGH AND SWIFT AS RECORD MOUNTAIN SNOWPACK CONTINUES TO SLOWLY MELT AND IS ASSISTED BY SHOWERS AND THUNDERSTORMS. SOME LOCATIONS WILL CONTINUE TO EXPERIENCE MINOR FLOODING. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER OR RIVER FLOODING. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
1 debris flow. 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, June 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: 327158.