Favorable upper level dynamics coupled with a cold front associated with an approaching Pacific storm system brought high winds to much of the area. Winds to 113 mph were recorded at ridgetop level on Mount Coffin, and maximum gusts of 76 mph were recorded at lower elevation at the Camp Creek RAWS site.
Every event with a place to put it; 10 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.
Favorable upper level dynamics coupled with a cold front associated with an approaching Pacific storm system brought high winds to much of the area. Winds to 113 mph were recorded at ridgetop level on Mount Coffin, and maximum gusts of 76 mph were recorded at lower elevation at the Camp Creek RAWS site. Wind gusts caused roof damage at a machinery plant in Bar Nunn, four miles north of Casper. Eastbound lanes of Interstate 80 on the east side of Rock Springs were closed after a truck was toppled near milepost 107 around 1230MST.
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 3, 10:30 AM MST, 2 hours 15 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 1130 AM MDT MON MAY 3 2010 SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT UPDATED TO EXTEND THE HIGH WIND WARNING FOR THE CODY FOOTHILLS AND ABSAROKA MOUNTAINS THROUGH 3 PM TUESDAY. LCL WRF IS SHOWING A STRONG MTN WAVE SIGNATURE AGAIN FOR TUESDAY MORNING WITH POTENTIAL FOR ANOTHER BOUT OF SIGNIFICANT WINDS. THE 06Z LCL WRF IS SHOWING 80KTS ON THE LEE SIDE OF THE ABSAROKAS AND 40-45KTS DOWN TO THE LOWEST GATE. ALSO ADDED IN THE WIND RIVER BASIN UP TO DUBOIS WITH FROPA AND IMPRESSIVE SFC GRADIENT...MID LEVEL FLOW AND 120KT JET MOVING OVHD. ALSO ADDED IN THE UPPER GREEN FOR TUESDAY FOR THE SAME REASONING. A WEAK FLAT RIDGE WILL BE BUILDING INTO THE AREA TODAY AS THE FLOW ALOFT BACKS TO THE WEST. A STRONG SHORTWAVE CURRENTLY RAPIDLY APPROACHING THE PACIFIC NORTHWEST COAST WILL STRENGTHEN THE INCREASINGLY DIFFLUENT WESTERLY FLOW TODAY AS IT TRACKS RAPIDLY EASTWARD ACROSS SOUTHERN CANADA AS IT CLOSES OFF. THIS LOW WILL TRAIL A STRONG TROUGH ACROSS WYOMING TONIGHT WITH AN EVER INCREASINGLY TIGHTENING GRADIENT. ISSUED A HIGH WIND WARNING FOR THE ABSAROKA MTNS AND THE CODY FOOTHILLS AS THE FLOW BACKS AND STRENGTHENS ACROSS NORTHERN WYOMING THROUGH THIS MORNING. CROSS SECTIONS INDICATE 70KNOT WINDS TO THE LEE OF THE ABSAROKA MOUNTAINS. THESE WINDS WILL LIKELY COME FUNNELING THROUGH THE CLARKS FORK GAP AFFECTING THE COMMUNITY OF CLARK. THESE WINDS WILL ALSO AFFECT THE NORTH AND SOUTH FORKS OF THE SHOSHONI RIVER CANYONS TO A SLIGHTLY LESSER EXTENT. THE RIGHT FRONT QUAD OF THE 135 KNOT JET WILL HELP DRAW DOWN THE 60 KNOT WINDS AT H7. THE CRAS INDICATES CLASSIC LEE ENHANCED AND MOUNTAIN WAVE CLOUD PATTERNS DURING THIS WIND EVENT AS THE WIND EVENT UNFOLDS. WAS NOT ABLE TO LOCATE A CRITICAL LAYER SUPPORTING A STRONG MTN WAVE BUT ALL OF THE AFOREMENTIONED INGREDIENTS INCLUDING A SUFFICIENT SURFACE AND H7 TIGHT PRESSURE GRADIENT SUPPORTS HIGH WIND. DID COME UP WITH A FROUDE NUMBER OF .95 FOR THE CLARK AREA HOWEVER. AS THE TROUGH MOVES SOUTHEAST ACROSS THE CWA THESE STRONG WINDS WILL SHIFT SOUTH ACROSS THE EAST SLOPE OF THE WIND RIVER MTNS AS WELL AS THE GREEN AND RATTLESNAKE MTNS BY 6 PM THIS EVENING. MANY MOS GUIDANCE PRODUCTS HAVE BEEN INDICATING 30 KNOT PLUS SUSTAINED WINDS. STRONG GRADIENT FLOW IS EXPECTED ACROSS THE SOUTHERN WIND CORRIDOR TONIGHT AND TUESDAY. EASTERN SWEETWATER COUNTY COULD START BLOWING HIGH WIND CRITERIA BY 3 AM TONIGHT THROUGH TUESDAY. KEPT ALL THE HIGH WIND WATCHES GOING BUT DELAYED THE WATCH FOR EASTERN SWEETWATER COUNTY UNTIL 3 AM. ANOTHER AREA OF CONCERN IS NORTHERN JOHNSON COUNTY. THE INITIAL PACIFIC FRONT WHICH WILL DIMINISH THE WINDS IN THE CODY AREA WILL ACTUALLY CAUSE POST FRONT WINDS TO INCREASE BY 12Z TUESDAY ACROSS NORTHERN JOHNSON COUNTY WHERE 3 HOURLY SURFACE PRESSURE RISES OF 8MB WILL ENHANCE POST FRONTAL WINDS THERE. THESE WINDS SHOULD CONTINUE THROUGH THE AFTERNOON WHEN A REINFORCING SURFACE BOUNDARY TRACKS SOUTH ACROSS THAT AREA LATER TODAY INFLUENCED BY THE SURFACE CYCLOGENESIS OVER EASTERN CO. THESE SAME WESTERLY DIFLUENT WINDS WILL PROVIDE A FAVORABLE MOIST UPSLOPE FLOW FOR THE NORTHWEST MOUNTAINS WHERE ADVISORY SNOW AMOUNTS ARE EXPECTED TO OCCUR THROUGH TUESDAY. KEPT THE CURRENT AMOUNTS OF SNOW EXPECTED IN THE FORECAST...HOWEVER DECIDED TO BUNCH UP THE SNOWFALL BETWEEN 09Z AND 15Z TUESDAY WHEN THE FRONT WILL SUPERIMPOSE LIFT FROM SURFACE CONVERGENCE WITH THE ONGOING UPSLOPE ENHANCED DYNAMICS. THE DAY SHIFT MAY NEED TO ISSUE A HILITE REGARDING THIS EVENT. LIGHTER RAIN AND SNOW SHOWERS WILL SPREAD SOUTH...EAST OF THE DIVIDE. THEN THE ATTENTION SHIFTS TO A PROMISING WIDESPREAD RAIN/SNOW EVENT FOR WEDNESDAY NIGHT. THE NEXT UPSTREAM LOW PRESSURE CENTER WILL TRACK EAST SOUTHEAST FROM THE PACIFIC NW TO WYOMING BY 12Z THU. STRONG Q VECTOR FORCING...WIDESPREAD ISENTROPIC LIFT AND GOOD LOW LEVEL UPSLOPE FLOW SUPPORTS A WIDESPREAD STRATIFORM PRECIP EVENT BEGINNING WED AND MAXING OUT WED NT. H7 TEMPS WILL BE COLD ENOUGH TO SUPPORT MOSTLY SNOW AFTER 06Z THU. FOR NOW HAVE INDICATED THE BULLS EYE OF SNOWFALL TO OCCUR OVER THE EAST SLOPE OF THE WIND RIVER MTNS WHERE A HALF A FOOT OF SNOW COULD FALL WITH AROUND 3 INCHES IN THE LANDER FOOTHILLS. LONG TERM...THURSDAY THROUGH MONDAY THERE IS STILL AN ISSUE WITH THE EXACT TRACK OF THE LATEST STORM SYSTEM WED NIGHT INTO THURSDAY. GFS REMAINS THE SOUTHERN WY TRACK WHILE THE CANADIAN MODEL IS MORE CENTRAL WY AND THE ECMWF RIDES THE NORTHERN WY TRACK. PLACEMENT OF THE BEST PRECIP CHANCE WILL EITHER BE THE NORTHERN ZONES OR THE CENTRAL ZONES WITH THE SOUTH ZONES SEEING LESS PRECIP. HAVE MADE MINOR CHANGES TO THURSDAY FORECAST TO ADD HIGHER PRECIP CHANCE TO THE NORTH AND CENTRAL ZONES. SCATTERED SHOWERS WILL LINGER THU EVENING THEN DECREASING AFTER MIDNIGHT. THE MODELS ARE INDICATING A WEST TO EAST FLOW ALOFT FRIDAY THROUGH SUNDAY WITH A PARADE OF SHORTWAVES IN THE FLOW. THIS WOULD GIVE THE MOUNTAINS THE BEST CHANCE OF PRECIP ALL THREE DAYS AS WELL AS THE FAR WEST VALLEYS. EAST OF THE DIVIDE WOULD HAVE ISOLATED SHOWERS FOR THE MOST PART. MADE CHANGES TO REFLECT THIS THINKING. EARLY NEXT WEEK A NEW STORM IS FORECAST TO ENTER THE WESTERN U.S. WITH POSSIBLE IMPACT TO THE WESTERN ZONES MONDAY PM AND MON NIGHT. AS FOR TEMPS... THURSDAY LOOKS UNSEASONABLY COOL...THEN GRADUAL WARMING THROUGH NEXT WEEKEND. AVIATION... A STORM SYSTEM SWINGING ACROSS THE NORTHERN ROCKIES AND SOUTHERN CANADA TODAY AND TONIGHT WILL RESULT IN VERY WINDY CONDITIONS DEVELOPING OVER MUCH OF THE REGION TODAY...AND LASTING THROUGH THE NIGHT. BY 18Z TODAY...STRONG WEST TO SOUTHWEST WINDS ARE EXPECTED OVER MUCH OF THE AREA...EXCEPT PERHAPS THE EASTERN BIG HORN BASIN AND NORTHERN JOHNSON COUNTY...INCLUDING KBYG...KGEY AND KWRL TERMINALS. WIND SPEEDS WILL GENERALLY BE 15 TO 30KT WITH GUSTS AROUND 40KT. THE STRONGEST WINDS WILL AFFECT AREAS IN THE CODY FOOTHILLS...KU25 /DUBOIS/...AND AREAS FROM KRKS TO KCPR. KCOD TERMINAL IS USUALLY SHIELDED FROM THE STRONGEST WINDS...BUT AREAS AROUND KCOD SHOULD SEE WESTERLY WINDS BETWEEN 20 AND 35KT...WITH GUSTS NEAR 50KT. THE ASSOCIATED COLD FRONT WITH THIS SYSTEM IS EXPECTED TO PUSH SOUTH ACROSS THE BIG HORN BASIN AND JOHNSON COUNTY BETWEEN 06Z AND 12Z TUESDAY...SWITCHING WINDS TO THE NORTHWEST. THIS SYSTEM ALSO WILL BRING A ROUND OF SNOW...MAINLY ACROSS THE NORTHWEST AND WEST LATE TODAY AND TONIGHT. THE BRUNT OF THE PRECIPITATION WILL BEGIN AFTER 21Z OVER NW WYOMING...THEN SLOWLY SLIDE SOUTH...MAINLY WEST OF THE DIVIDE DURING THE NIGHT. MVFR/IFR CONDITIONS ARE LIKELY TO DEVELOP OVER MUCH OF THE NORTHWEST MOUNTAINS BETWEEN 21Z MONDAY AND 03Z TUESDAY. KJAC TERMINAL WILL HAVE A GOOD CHANCE FOR RAIN AND SNOW WITH MVFR CEILINGS / IFR VISIBILITIES BETWEEN 03Z AND 09Z TUESDAY. RAIN SHOULD CHANGE TO SNOW BETWEEN 03 AND 06Z TUESDAY. KBPI AND KPNA TERMINALS COULD BE IMPACTED BY THE RAIN/SNOW...MAINLY AFTER 06Z BUT WIDESPREAD PRECIPITATION IN THE UPPER GREEN RIVER BASIN IS NOT EXPECTED. THUS WILL HANDLE KBPI AND KPNA WITH VCSH FOR NOW. OTHER TAF SITES SHOULD REMAIN DRY...WITH VFR...BUT WINDY CONDITIONS DOMINATING. THE EXCEPTION WILL BE CEILINGS AROUND MVFR BEHIND THE COLD FRONT OVER THE BIG HORN BASIN/JOHNSON COUNTY TONIGHT. FIRE WEATHER... VERY WINDY WEATHER IS EXPECTED ACROSS MOST OF WESTERN AND CENTRAL WYOMING TODAY THROUGH TUESDAY AS A TIGHTENING PRESSURE GRADIENT OCCURS AND A COLD FRONT TRACKS SOUTH ACROSS WYOMING. THIS SAME FRONT WILL PRODUCE ACCUMULATING SNOWFALL MAINLY IN NORTHWEST WYOMING DURING THIS TIME FRAME. ANOTHER WIDESPREAD RAIN AND SNOW EVENT IS SLATED FOR WEDNESDAY NIGHT. TEMPERATURES WILL BE WARMER TODAY...THEN COOLING AGAIN TUESDAY BEHIND THE FRONT. && .RIW WATCHES/WARNINGS/ADVISORIES... HIGH WIND WATCH FROM LATE TONIGHT THROUGH TUESDAY AFTERNOON WYZ030. HIGH WIND WATCH FROM 6 PM MDT THIS EVENING THROUGH TUESDAY AFTERNOON WYZ015-018-019. HIGH WIND WATCH FROM TUESDAY MORNING THROUGH TUESDAY AFTERNOON WYZ010. HIGH WIND WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING WYZ017-025-026. HIGH WIND WATCH FROM LATE TONIGHT THROUGH TUESDAY AFTERNOON WYZ016. HIGH WIND WARNING UNTIL 3 PM MDT TUESDAY WYZ002-003. HIGH WIND WATCH FROM 9 PM MDT THIS EVENING THROUGH TUESDAY AFTERNOON WYZ020. && UPDATE...SKRBAC SHORT TERM...LIPSON LONG TERM...AR AVIATION...AR FIRE WEATHER...LIPSON
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 1140 AM MDT MON MAY 3 2010 WYZ001>020-022>030-041200- 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- 1140 AM MDT MON MAY 3 2010 ...HIGH WIND WARNING IN EFFECT FOR THE ABSAROKA MOUNTAINS AND THE CODY FOOTHILLS THROUGH TUESDAY AFTERNOON... ...HIGH WIND WATCHES ARE IN EFFECT FOR MUCH OF CENTRAL AND SOUTHERN WYOMING STARTING THIS EVENING THROUGH TUESDAY AFTERNOON... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT A STORM SYSTEM WILL AFFECT THE AREA THIS AFTERNOON AND TONIGHT. A TIGHT PRESSURE GRADIENT AND STRONG WINDS ALOFT...WILL COMBINE FOR VERY STRONG WESTERLY WINDS OVER THE ABSAROKA MOUNTAINS AND CODY FOOTHILLS THIS AFTERNOON THROUGH EARLY TUESDAY MORNING. THE STRONG WINDS WILL DIMINISH IN THE CODY FOOTHILLS AND THE ABSAROKA MOUNTAINS BY 3 AM TONIGHT. VERY STRONG WEST TO SOUTHWEST WINDS ARE ALSO POSSIBLE ACROSS THE EASTERN WIND RIVER MOUNTAINS...LANDER FOOTHILLS AND FROM EASTERN SWEETWATER COUNTY...NORTHEAST ACROSS SOUTHEAST FREMONT COUNTY...INTO MUCH OF NATRONA COUNTY TONIGHT. WIND SPEEDS IN THESE AREAS COULD RANGE BETWEEN 35 AND 45 MPH...WITH GUSTS OVER 60 MPH IN THE LOWER ELEVATIONS. IN THE MOUNTAIN WATCH AREAS EXPECT WIND SPEEDS AROUND 50 MPH...WITH GUSTS AROUND 75 MPH AT TIMES. THIS STORM SYSTEM ALSO HAS THE POTENTIAL TO BRING MODERATE AMOUNTS OF SNOWFALL LATE TONIGHT ACROSS THE NORTHWEST MOUNTAINS...WITH 3 TO 7 INCHES OF SNOW AND ISOLATED HIGHER AMOUNTS POSSIBLE. STRONG WINDS WILL CREATE BLOWING AND DRIFTING OF THE SNOW. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY STRONG WEST WINDS WILL PERSIST ACROSS MANY AREAS OF CENTRAL AND SOUTHERN WYOMING TUESDAY INCLUDING FREMONT...NATRONA...SWEETWATER AND SUBLETTE COUNTIES. WIND OF 40 MPH AND GUSTS OF 60 MPH AT SOME OF THE LOWER ELEVATIONS. STRONGER WIND IS EXPECTED TO OCCUR OVER THE EASTERN SLOPES OF THE ABSAROKA MOUNTAINS AND INTO THE WESTERN HALF OF THE CODY FOOTHILLS LATE TUESDAY MORNING THROUGH THE AFTERNOON. WIND OF 40 TO 50 MPH WITH GUSTS OF 75 MPH OR GREATER ARE EXPECTED OCCUR OVER THIS AREA. STRONG NORTHWEST WINDS OF 40 MPH WITH GUSTS TO 60 MPH ARE POSSIBLE IN NORTHERN JOHNSON COUNTY INCLUDING THE CITY OF BUFFALO TUESDAY BEHIND A COLD FRONT. ANOTHER STORM SYSTEM HAS THE POTENTIAL TO BRING SIGNIFICANT SNOWFALL TO AREAS EAST OF THE DIVIDE WEDNESDAY NIGHT AND THURSDAY. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT WIND SPEEDS OF 40 MPH OR HIGHER... AS WELL AS ANY WIND GUSTS OVER 55 MPH TODAY AND TUESDAY. THANK YOU. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
10 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, May 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: 229143, 229136, 229134, 229138, 229141, 229137, 233722, 235662, 235718, 229139.