Favorable jet stream dynamics coupled with a cold frontal passage brought high winds to south-central Wyoming. Higher elevations near US Highway 287 experienced gusts to 69 mph.
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The episode as NWS RIW wrote it up.
Favorable jet stream dynamics coupled with a cold frontal passage brought high winds to south-central Wyoming. Higher elevations near US Highway 287 experienced gusts to 69 mph. Sustained wind speeds of 40 mph or more were common along Interstate 80 through eastern Sweetwater County and along state highway 220 in southern Natrona County.
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 Apr 2, 1:43 PM MST, 8 hours 27 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 243 PM MDT FRI APR 2 2010 SHORT TERM...TONIGHT THROUGH MONDAY VERY ACTIVE WEATHER PATTERN WILL CONTINUE FOR THE FORESEEABLE FUTURE. THE NEXT STORM SYSTEM IS ALREADY BEARING DOWN ON THE WEST WITH SNOW EXPECTED TO DEVELOP EARLY THIS EVENING. COMBINATION OF ISENTROPIC UPGLIDE...JET STREAK DYNAMICS AND SOME QG FORCING SHOULD PROVIDE A POTENT PUNCH OVERNIGHT. THE SNOW SHOULD TAPER OFF IN THE SOUTH SATURDAY MORNING AND IN THE NORTH BY AFTERNOON. IN THE WIND CORRIDOR...THE SURFACE GRADIENT IS EXPECTED TO INCREASE TO BETWEEN 13MB AND 16MB BETWEEN RKS AND GCC OVERNIGHT WHILE H7 WINDS BACK TO THE SW AND INCREASE TO 50KTS. SW WINDS WILL INCREASE RAPIDLY THIS EVENING AND INCREASE INTO SATURDAY MORNING BEFORE FROPA. ACROSS THE I80 CORRIDOR...THE WINDS ARE EXPECTED TO INCREASE RAPIDLY SATURDAY MORNING AS THE COLD FRONT BLOWS THROUGH. IN ADDITION TO THE POTENTIAL FOR HIGH WINDS DEVELOPING...WE SHOULD ALSO SEE A PERIOD OF SNOW SHOWERS WHICH WILL SHARPLY REDUCE THE VISIBILITY WHEN COMBINED WITH THE STRONG TO HIGH WINDS. THE CODY FOOTHILLS HAVE A BRIEF MTN WAVE SIGNATURE AROUND MIDNIGHT TONIGHT BUT IT IS VERY BRIEF. THE EVENING CREW CAN WATCH THIS CLOSELY. FOR NOW...JUST INCREASED THE WINDS QUITE A BIT. THE TROUGH AXIS WILL PASS ACROSS THE NORTH ON SATURDAY WITH THE FRONT PUSHING DOWN FROM THE SOUTH UP THERE LEADING TO SOME LIGHT SNOW POTENTIAL ALONG THIS BOUNDARY. AND THEN SATURDAY NIGHT...A LEAD SHORTWAVE AHEAD OF THE MAIN DIGGING TROUGH WILL BRING A QUICK RETURN TO SNOW IN THE SW HALF LATE SATURDAY NIGHT ON INCREASING ISENTROPIC UPGLIDE. THIS BAND OF SNOW WILL LIKELY LIFT NWD INTO THE CENTRAL ZONES ON EASTER MORNING FOR A QUICK SHOT OF SNOW. AFTER A BRIEF RESPITE OR AT LEAST DECREASE IN THE SNOW...ANOTHER SYSTEM WITH WARMER AIR WILL BRING ANOTHER ROUND OF PCPN TO THE SOUTH SUNDAY EVENING...MOVING RAPIDLY NORTH THROUGH THE NIGHT. H7 TEMPS WARM CONSIDERABLY SO WE'LL HAVE TO WATCH THE MIN TEMPS AS TO WHETHER IT WILL BE ALL SNOW. WITH THE NIGHTTIME ARRIVAL...MOST OF IT WILL LIKELY BE SNOW BUT THERE COULD BE A LITTLE RAIN MIXTURE IN THE WARMEST LOCALES. COULD EVEN BE SOME LIGHT FREEZING RAIN. THE WEST WILL ALSO SEE WIDESPREAD ISENTROPIC UPGLIDE PCPN BEGINNING SUNDAY NIGHT AND THEN TRANSITIONING TO STRONGER TROUGH DYNAMICS ON MONDAY FOR MORE POTENTIALLY SIGNIFICANT SNOW. QUITE AN ACTIVE AND BUSY PATTERN THIS PAST WEEK AND NO LETUP IN SIGHT YET. LONG TERM...MONDAY NIGHT THROUGH FRIDAY THE FIRST PART OF THE WORK WEEK LOOKS TO BE THE MOST ACTIVE...AS YET ANOTHER STORM SYSTEM TAKES AIM FOR THE COWBOY STATE. ON MONDAY THE AREA WILL BE IN THE SOUTHWESTERLY FLOW AHEAD OF THE TROUGH ACROSS THE WEST COAST. A LEE TROUGH IS EXPECTED TO DEVELOP ON MONDAY IN RESPONSE TO THE APPROACHING STORM SYSTEM. THIS IN ADDITION TO STRENGTHEN 700MB FLOW BETWEEN 30 AND 50 KTS WILL MAKE FOR A WINDY DAY FROM KRKS TO KCPR. THE GFS HAS BEEN VERY CONSISTENT OVER THE PAST 3-4 DAYS IN SHOWING LIFTED INDEXES AROUND -2 AND STEEP LAPSE RATES BETWEEN 7 AND 8.5 DEG CELSIUS. THUS HAVE ADDED THUNDERSTORMS TO THE MIX ON MONDAY AFTERNOON AND EVENING. THE 00Z ECMWF HAS TRENDED TOWARDS THE GFS SOLUTION WITH THE EASTWARD PROGRESSION OF THE TROUGH...BUT STILL A BIT SLOWER ESPECIALLY AFTER TUESDAY. MEDIUM RANGE MODELS ARE IN DECENT AGREEMENT WITH THE COLD FRONT PUSHING ACROSS THE AREA MONDAY NIGHT AND TUESDAY. HAVE INCREASED POPS TO CHANCE CATEGORY ACROSS THE ENTIRE AREA MONDAY NIGHT AND TUESDAY...WITH AN EMPHASIS IN FAVORED UPSLOPE AREAS...ESPECIALLY ON TUESDAY. HAVE CONTINUED TO COOL TEMPERATURES ON TUESDAY...AS 700MB TEMPS DROP TO AROUND -10 DEG CELSIUS. THIS COLD AIR ADVECTION AND GOOD CHANCE FOR CLOUD COVER AND SNOWFALL WILL PROBABLY RESULT IN TEMPS GENERALLY IN THE LOWER 30S. HOWEVER HAVE NOT GONE THAT COOL YET...AND WILL LET LATER SHIFTS CONTINUE TO DROP TEMPS AS THE SYSTEM CERTAINTY INCREASES. COULD SEE SOME LINGERING SNOWFALL...ESPECIALLY OUT EAST ON WEDNESDAY...AS THE SYSTEM SLOWLY EXITS. WEAK RIDGING IS EXPECTED THURSDAY AND FRIDAY...AHEAD OF THE NEXT BIG TROUGH NEXT WEEKEND. THERE IS A CHANCE THAT WEAK DISTURBANCES AHEAD OF THIS TROUGH IN THE WEAK RIDGING THURSDAY/FRIDAY COULD PRODUCE MORE PRECIPITATION THAN CURRENTLY FORECAST. TEMPERATURES IN THE EXTENDED WILL GENERALLY BE BELOW AVERAGE...WITH THE BEST SHOT AT SEASONAL TO SLIGHTLY ABOVE AVERAGE ON MONDAY AND THEN LATE NEXT WEEK. AVIATION... A PACIFIC STORM SYSTEM OVER THE PACIFIC NORTHWEST WILL BE APPROACHING WYOMING TONIGHT AND WILL RAPIDLY TRACK EAST ACROSS WYOMING SATURDAY. SNOW AND LOWERING CIGS WILL RESULT ACROSS WESTERN WYOMING TONIGHT WITH THE SNOW FIRST BREAKING OUT ACROSS KJAC AS EARLY AS 00Z THIS EVENING BEFORE SPREADING EAST NORTHEAST ACROSS THE REST OF WESTERN WYOMING INCLUDING KBPI AND KPNA BY 03Z. MVFR AND EMBEDDED IFR CONDITIONS AS WELL AS MOUNTAIN OBSCURATIONS WILL RESULT. THIS SNOWFALL WILL PERSIST THROUGH 15Z SATURDAY. THE PRESSURE GRADIENT WILL INCREASE OUT AHEAD OF THIS APPROACHING WEATHER SYSTEM. AS A RESULT SOUTHWEST WINDS WILL INCREASE TO SPEEDS OF 30 TO 40 MPH WITH GUSTS TO 60 MPH FROM THE GREEN MOUNTAINS TO KCPR BY 03Z THIS EVENING AND PERSISTING THROUGH 18Z SATURDAY. WEST WINDS OF 30 TO 40 MPH WITH GUSTS TO 60 MPH WILL OCCUR ACROSS SWEETWATER COUNTY INCLUDING KRKS FROM 12Z SATURDAY THROUGH 18Z SATURDAY DURING WHICH TIME THE ASSOCIATED PACIFIC COLD FRONT WILL TRACK EAST ACROSS WYOMING. FIRE WEATHER... MORE SNOW WILL MOVE INTO THE WEST TONIGHT AND CONTINUE THROUGH SATURDAY. EAST OF THE DIVIDE...STRONG TO HIGH WINDS WILL DEVELOP TONIGHT FROM GREEN MOUNTAINS AND RATTLESNAKE RANGE OVER TO CASPER. ANOTHER VERY WINDY AREA WILL BE ALONG THE EAST SLOPE OF THE ABSAROKA MOUNTAINS AND POTENTIALLY INTO THE CODY FOOTHILLS. A STRONG COLD FRONT WILL PUSH ACROSS THE STATE SATURDAY PRODUCING STRONG WEST WINDS WITH HIGH WINDS POSSIBLE ALONG INTERSTATE 80 ALONG WITH SNOW SHOWERS. AN ACTIVE WEATHER PATTERN WILL BRING SEVERAL PERIODS OF SNOW OUT WEST THROUGH EARLY NEXT WEEK. SOME LIGHT SNOW WILL ALSO MOVE FROM SOUTHERN WYOMING INTO CENTRAL WYOMING LATER SATURDAY NIGHT INTO SUNDAY MORNING. && .RIW WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING FROM MIDNIGHT TONIGHT TO NOON MDT SATURDAY WYZ020. WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON MDT SATURDAY WYZ023>025-027. HIGH WIND WARNING FROM 9 PM THIS EVENING TO NOON MDT SATURDAY WYZ019. WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM MDT SATURDAY WYZ001-012-013. HIGH WIND WATCH FROM SATURDAY MORNING THROUGH SATURDAY AFTERNOON WYZ028-030. && SHORT TERM...SKRBAC LONG TERM...WM AVIATION...LIPSON FIRE WEATHER...SKRBAC
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 342 PM MDT FRI APR 2 2010 WYZ001>020-022>030-031100- 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- 342 PM MDT FRI APR 2 2010 ...WINTER WEATHER ADVISORIES FOR WESTERN WYOMING FOR TONIGHT AND SATURDAY... ...HIGH WIND WARNING FROM THE GREEN MOUNTAINS TO CASPER FOR TONIGHT AND SATURDAY MORNING... ...HIGH WIND WATCH FOR SWEETWATER COUNTY INCLUDING ROCK SPRINGS FOR SATURDAY... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TONIGHT SNOWFALL WILL DEVELOP RAPIDLY EARLY THIS EVENING ACROSS WESTERN WYOMING WITH AREA HIGHWAYS QUICKLY BECOMING SLICK WITH SNOWFALL. STRONG SOUTHWEST WINDS OF 30 TO 40 MPH WITH TO GUSTS 60 MPH ARE EXPECTED TO DEVELOP IN THE GREEN MOUNTAINS THIS EVENING BEFORE SPREADING EAST TO THE CASPER AREA BY MIDNIGHT TONIGHT. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY SNOW WILL CONTINUE IN MUCH OF WESTERN WYOMING THROUGH NOON TODAY BUT WILL CONTINUE IN NORTHWEST WYOMING THROUGH SATURDAY AFTERNOON. IN THE ADVISORY AREA...5 TO 12 INCHES OF TOTAL SNOW ACCUMULATION IS EXPECTED IN THE MOUNTAINS ALONG WITH 3 TO 6 INCHES IN THE LOWER ELEVATIONS. LESSER AMOUNTS OF ACCUMULATING SNOW ARE EXPECTED ACROSS THE REST OF WESTERN WYOMING DURING THIS TIME FRAME. STRONG SOUTHWEST OF 30 TO 40 MPH WITH GUSTS TO 60 MPH WINDS WILL CONTINUE FROM THE GREEN MOUNTAINS TO CASPER THROUGH NOON ON SATURDAY. WEST SOUTHWEST WINDS OF 30 TO 40 MPH WITH GUSTS TO 60 MPH ARE ALSO POSSIBLE IN SWEETWATER COUNTY INCLUDING ROCK SPRINGS BY 6 AM SATURDAY MORNING AND COULD CONTINUE THERE THROUGH 6 PM SATURDAY. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT SNOWFALL OVER 2 INCHES. THANK YOU. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
3 high wind. Local standard time, as filed.
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, April 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: 215129, 215131, 215130.