A fast moving storm and associated cold front brought high winds to portions of Natrona County. Winds gusted as high as 65 mph at Fales Rock in the Rattlesnake Range and 58 mph along US Highway 20/26 near Hiland.
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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 fast moving storm and associated cold front brought high winds to portions of Natrona County. Winds gusted as high as 65 mph at Fales Rock in the Rattlesnake Range and 58 mph along US Highway 20/26 near Hiland.
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 13, 10:27 AM MST, 1 hour 49 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 1127 AM MDT SAT APR 13 2013 .SHORT TERM...SATURDAY THROUGH MONDAY NIGHT THE ACTIVE WEATHER PATTERN LOOKS TO CONTINUE ACROSS THE AREA THROUGH MOST OF THE SHORT RANGE FORECAST. AS FOR TODAYS SYSTEM...POCATELLO RADAR IS ALREADY SHOWING THE FIRST SHOT OF WARM ADVECTION MOVING INTO THE EASTERN HIGHLANDS OF IDAHO AND THIS WILL CROSS INTO WESTERN WYOMING BEFORE DAWN THIS MORNING. STEADIEST AND HEAVIEST PRECIPITATION STILL LOOKS TO OCCUR DURING THE MORNING HOURS WITH THE BEST UPPER LEVEL SUPPORT WITH THE LEFT FRONT QUADRANT OF THE JET MOVING INTO THE AREA. CURRENT HIGHLIGHTS LOOK GOOD FOR NOW. I HAVE SOME CONCERN ABOUT THE VALLEYS BUT WITH TEMPERATURES EXPECTED TO RISE A BIT THERE WILL LIKELY BE SOME MIXING AND POSSIBLY CHANGEOVER AT TIMES TO RAIN. PLUS...WITH THE STRONG APRIL SUN THERE MAY NOT BE A LOT OF ACCUMULATION ON ROADS TOWARD MIDDAY AND THE AFTERNOON. SO WE HELD OFF FOR NOW. WILL WILL ISSUE AN SPS HOWEVER FOR POSSIBLE SLICK DRIVING CONDITIONS AT TIMES. MEANWHILE...THE CONCERN FOR EAST OF THE DIVIDE WILL BE THE WIND. WE WERE ON THE FENCE FOR ISSUING A HIGH WIND WARNING FOR THIS AFTERNOON IN A FEW SPOTS. THE FACTORS FOR THE HIGH WIND WARNING ARE STRONG 700 MILLIBAR WINDS OF 50 TO 55 KNOTS OVER PORTIONS THE GREEN MOUNTAINS AND NATRONA COUNTY ALONG WITH A TIGHTENING GRADIENT WITH THE APPROACHING COLD FRONT. FACTORS AGAINST INCLUDE SOME MID AND HIGH LEVEL CLOUDS THAT MAY LIMIT MIXING. WE WILL ISSUE A HIGH WIND WARNING FOR NATRONA COUNTY AS WELL AS FOR THE GREEN AND RATTLESNAKE RANGE ALTHOUGH IT IS BORDERLINE. AS FOR CHANCES OF PRECIPITATION...THE BEST CHANCE LOOKS TO BE ACROSS NORTHERN AREAS BUT AMOUNTS LOOK MINIMAL. THE CHANCE OF SHOWERS WILL LINGER INTO TONIGHT BUT AGAIN MOST AREAS WILL BE PRECIPITATION FREE MOST OF THE TIME. FOR SUNDAY...THE QUESTION IS WHAT WILL HAPPEN IN NORTHEASTERN PORTIONS OF THE AREA. AS THE AFOREMENTIONED LOW WRAPS UP IN THE NORTHERN PLAINS SOME MOISTURE MAY TRY TO WRAP BACK AROUND IT. MODELS CONTINUE TO BE SPLIT ON HOW FAR SOUTH IT WILL REACH. THE NAM KEEPS MOST OF IT NORTH OF THE AREA WITH THE GFS AND EUROPEAN A BIT FURTHER SOUTH WITH ANY QPF. FOR NOW...WE PLAYED THE MIDDLE GROUND WITH SLIGHT CHANCE TO CHANCE POPS ACROSS JOHNSON COUNTY AND LIKELY POPS IN THE BIGHORN RANGE. WE KEPT AMOUNTS LOWER BUT THIS IS A CLOSE CALL. IT COULD STILL BE NASTY SINCE STRONG NORTHWEST FLOW WILL BRING WINDY CONDITIONS. MOST OTHER AREAS EAST OF THE DIVIDE SHOULD BE MAINLY DRY BUT BREEZY AND COOLER. MEANWHILE...WEST OF THE DIVIDE SHOWERS WILL CONTINUE WITH WESTERLY UPSLOPE FLOW. THE LAST QUESTION IS WHAT WILL HAPPEN WITH THE POTENTIAL STORM FOR THE BEGINNING OF NEXT WEEK. MODELS ARE AGAIN SPLIT A BIT WITH THE EUROPEAN THE FASTEST AND FURTHER NORTH AND THE GFS AND ESPECIALLY THE NAM CONTINUING TO TREND FURTHER SOUTH. AT THIS POINT...ALL THE MODELS KEEP THE WORST OF THE PRECIPITATION SOUTHEAST OF THE RIVERTON COUNTY WARMING AREA BUT THIS IS SUBJECT THE CHANGE. THE ONLY CHANGES WE MADE WERE TO SLOW DOWN THE ARRIVAL OF ANY POTENTIAL SNOW A BIT ON MONDAY AS THE BULK OF ANYTHING MAY HOLD OFF UNTIL TUESDAY. STAY TUNED FOR ANY CHANGES. .LONG TERM...TUESDAY THROUGH SATURDAY TUESDAY AND TUESDAY NIGHT REMAIN UNSETTLED WITH SOME SNOW FOR THE REGION AND COLD TEMPERATURES. LOW LEVEL EASTERLY FLOW WITH MOISTURE FORECAST TO GLIDE OVER THE COLD AIR DOME SETTING UP SNOWFALL EAST OF THE DIVIDE. LESSER SNOWFALL FOR THE BIG HORN BASIN AND NORTHWEST WY. THE LONG RANGE MODELS SEEM TO BE TRENDING FARTHER SOUTH WITH THE TROUGH AND SETTING UP THE PRECIP MORE TO THE SOUTH THAN A FEW DAYS AGO. THIS NEEDS WATCHING OVER THE COMING DAYS. FOR NOW WILL NOT STRAY FAR FROM GOING FORECAST. WEDNESDAY ALSO LOOKS COLD WITH LINGERING LIGHT SNOW OR SNOW SHOWERS AS THE TROUGH CONTINUES TO PUSH THROUGH THE AREA. CONDITIONS IMPROVE WEDNESDAY NIGHT WITH SNOW SHOWERS ENDING AFTER MIDNIGHT. A NORTH NORTHWEST FLOW ON THURSDAY WITH ENOUGH MOISTURE IN THE FLOW FOR MOUNTAIN SNOW SHOWERS. FRIDAY INTO SATURDAY THE GFS MODEL HAS A FEW WEATHER SYSTEMS IN A NW FLOW ALOFT WHICH WOULD LEAD TO A GOOD CHANCE OF MOUNTAIN PRECIP AND SCATTERED COVERAGE AT THE LOWER ELEVATIONS...WITH BREEZY TO WINDY CONDITIONS. THE ECMWF IS SIMILAR TO GFS FRI/SAT WITH DISTURBANCES IN THE NW FLOW. TEMPS WILL MODERATE FROM THURSDAY THROUGH SATURDAY. .AVIATION.../18Z ISSUANCE/ EAST OF THE DIVIDE...KCPR/KCOD/KLND/KRIW/KWRL ROUTES. VERY WINDY CONDITIONS WILL OCCUR OVER MUCH OF THE REGION...ESPECIALLY FROM SOUTH PASS TO KCPR. LOW LEVEL WIND SHEAR WILL BE POSSIBLE IN THE FOOTHILLS ON THE LEE SIDE OF THE MOUNTAIN RANGES. STRONG DOWN SLOPING CONDITIONS WILL RESULT IN LITTLE PRECIPITATION AND VFR CONDITIONS EAST OF THE DIVIDE THROUGH EARLY AFTERNOON. HOWEVER...MOUNTAINS ALONG THE DIVIDE AND ACROSS THE NORTH WILL HAVE IFR/LIFR CONDITIONS IN SNOW AND LOW CEILINGS OBSCURING TERRAIN...WITH MODERATE TO SEVERE TURBULENCE. A COLD FRONT WILL PUSH SOUTH INTO NORTHERN WYOMING BY AROUND 21Z...AND REACH THE DIVIDE BY AROUND 06Z SUNDAY. SOME SHOWER ACTIVITY AND LOW CLOUDS ARE POSSIBLE IN WAKE OF THE COLD FRONT...BUT WIDESPREAD IFR/MVFR CONDITIONS ARE NOT EXPECTED. WEST OF THE DIVIDE...KJAC/KRKS/KBPI/KPNA ROUTES. SNOW ACROSS WESTERN WYOMING WILL INTENSIFY WITH WIDESPREAD MVFR/IFR CONDITIONS IN SNOW AND LOW CEILINGS...ESPECIALLY ACROSS FAR WESTERN WYOMING OBSCURING TERRAIN. IFR CONDITIONS ARE VERY LIKELY AT KJAC THROUGH 21Z. KJAC AIRFIELD MINIMUMS ARE POSSIBLE AT TIMES THROUGH..DUE TO LOW VISIBILITY IN SNOW. IMPROVING CONDITIONS ARE EXPECTED AFTER 21Z...BUT SNOW SHOWER ACTIVITY WILL REMAIN POSSIBLE THROUGH ABOUT 03Z SUNDAY. ALTHOUGH THERE COULD BE SOME RAIN MIXED IN WITH SNOW...OR ALL RAIN BELOW 6500 FEET. KAFO...KBPI AND KPNA WILL HAVE PERIODS OF MVFR/IFR CONDITIONS IN SNOW/RAIN MAINLY BETWEEN 18Z AND 22Z. ACROSS SWEETWATER COUNTY THE MAIN IMPACT WILL BE WINDY WEST WINDS...BUT THERE COULD BE SOME RAIN/SNOW SHOWERS AFFECTING KRKS BETWEEN 21Z AND 03Z SUNDAY. MOUNTAINS WILL BE OBSCURED TODAY WITH LIFR CONDITIONS ACROSS MOUNTAIN PASSES...AND PROBABLY MODERATE TO SEVERE TURBULENCE. PLEASE SEE THE AVIATION WEATHER CENTER FOR THE LATEST INFORMATION ON ICING AND TURBULENCE FORECAST. .FIRE WEATHER... A QUICK MOVING SNOW STORM WILL DELIVER SNOWFALL TO THE WESTERN WYOMING MOUNTAINS ABOVE 8000 FEET TODAY. COLDER AIR WILL FILTER INTO THE AREA BEHIND THIS WEATHER SYSTEM. CENTRAL AND SOUTHERN WYOMING WILL HAVE THE POTENTIAL FOR WIDESPREAD SNOWFALL MONDAY THROUGH TUESDAY. STRONG SOUTHWEST WINDS ARE EXPECTED FROM SOUTHERN LINCOLN COUNTY THROUGH SWEETWATER COUNTY TO CASPER TODAY. && .RIW WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING UNTIL 7 PM MDT THIS EVENING WYZ019-020. WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING WYZ001-012-014-024. && SHORT TERM...HATTINGS LONG TERM...AR AVIATION...C.BAKER FIRE WEATHER...HATTINGS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 315 AM MDT SAT APR 13 2013 WYZ001>020-022>030-141200- 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- 315 AM MDT SAT APR 13 2013 ...WINTER WEATHER ADVISORY TODAY FOR MUCH OF THE WESTERN MOUNTAINS... ...HIGH WIND WARNING IN EFFECT FOR NATRONA COUNTY AND THE GREEN AND RATTLESNAKE RANGE THIS AFTERNOON... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT SNOW AND BLOWING SNOW EXPECTED IN THE WESTERN MOUNTAINS. PLEASE SEE THE WINTER WEATHER STATEMENT FOR MORE DETAILS. STRONG WINDS ARE FORECAST ACROSS NATRONA COUNTY AND IN THE GREEN MOUNTAINS AND RATTLESNAKE RANGE FROM MIDDAY THROUGH LATE AFTERNOON. WIND GUSTS TO 60 MPH ARE FORECAST FOR THE WARNED AREAS. SEE THE LATEST HIGH WIND WARNING STATEMENT FOR MORE DETAILS. WINDY WEATHER WILL ALSO BE FOUND ALONG SOUTHERN WYOMING FROM KEMMERER TO WAMSUTTER AND ALONG THE CODY FOOTHILLS. WIND GUSTS OF 40 TO 50 MPH ARE EXPECTED FROM LATE MORNING UNTIL SUNSET. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY MONDAY AFTERNOON THROUGH TUESDAY NIGHT...A LONG DURATION OF SNOW POSSIBLE IN UPSLOPE FAVORED AREAS EAST OF THE CONTINENTAL DIVIDE... ESPECIALLY FROM THE EAST SLOPES OF THE WIND RIVER MOUNTAINS TO THE CASPER AREA. A GUSTY NORTHEAST WIND...ALONG WITH SNOW AND BLOWING SNOW...WILL BE LIKELY ALONG THE INTERSTATE 80 CORRIDOR. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT SNOW AMOUNTS. THANK YOU. TEAM RIVERTON
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 116 PM MDT SAT APR 13 2013 WYZ001-132115- YELLOWSTONE NATIONAL PARK- 116 PM MDT SAT APR 13 2013 ...THUNDERSTORMS HEADING TOWARDS YELLOWSTONE NATIONAL PARK... A LINE OF THUNDERSTORMS WITH SMALL HAIL...GUSTY WINDS AND DANGEROUS LIGHTNING IN EASTERN IDAHO WILL MOVE ACROSS YELLOWSTONE NATIONAL PARK FROM 116 PM MDT THROUGH 4 PM MDT THIS AFTERNOON. WIND GUSTS TO 45 MPH CAN BE EXPECTED. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
2 high wind. Local standard time, as filed.
Wind gusts of 58 mph were reported at Hiland.
Winds gusted to 65 mph a Fales Rock and 63 mph at Beaver Rim.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2013Every state in 2013This day in weather historyWarnings in Wyoming, April 2013
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: 435265, 435264.