A weak disturbance and associated cooling aloft helped to generate showers and thunderstorms over eastern Idaho during the afternoon. A couple of these storms became severe over the far western valleys of Wyoming.
Every event with a place to put it. 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.
A weak disturbance and associated cooling aloft helped to generate showers and thunderstorms over eastern Idaho during the afternoon. A couple of these storms became severe over the far western valleys of Wyoming.
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 Jul 6, 10:40 AM MST, 1 hour 38 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 1140 AM MDT SAT JUL 6 2013 .SHORT TERM...SATURDAY THROUGH MONDAY NIGHT UPDATED TO INCREASE PRECIPITATION CHANCES TO LIKELY ACROSS ALL OF THE WEST THIS AFTERNOON AND EARLY EVENING ALONG WITH SOME SEVERE WORDING. GOOD DAYTIME HEATING WILL COMBINE WITH AN APPROACHING THERMAL TROUGH AND SHORTWAVE TO DESTABILIZE THE ATMOSPHERE CONSIDERABLY. ANY AREA COULD HAVE HAVE STRONG STORMS BUT THE WEST LOOKS THE BEST AND POTENTIALLY THE NORTH. ANOTHER ACTIVE DAY FOR SURE. RADAR IS STILL SHOWING VERY LIGHT SHOWERS BUT THE SEVERE WEATHER OF EARLIER THIS EVENING HAS ENDED. SATELLITE IMAGERY CONTINUES TO SHOW WARMING CLOUD TOPS AND SOMEWHAT DRIER AIR MOVING IN FROM THE WEST FOR LATER FRIDAY NIGHT SO ALTHOUGH WE HAVE LEFT SOME SLIGHT POPS MOST AREAS SHOULD BE RAIN FREE UNTIL DAYBREAK SATURDAY. BOTH THE NAM ANS GFS SHOW SOMEWHAT DRIER AIR MOVING IN FOR TOMORROW MORNING...ESPECIALLY ACROSS NORTHWESTERN WYOMING WHERE PRECIPITABLE WATER VALUES ARE EXPECTED TO DROP DOWN TO UNDER 0.50 INCHES. AS A RESULT...WE HAVE LOWERED POPS FOR THE MORNING HOURS FOR MANY AREAS. ALTHOUGH THERE WILL BE SOME SHOWERS AROUND...MOST AREAS SHOULD BE RAIN FREE THROUGH NOON. HOWEVER...IT LOOKS AS THROUGH ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL ONCE AGAIN DEVELOP ACROSS MUCH OF THE COUNTY WARNING AREA FOR THIS AFTERNOON AND EVENING AS YET ANOTHER SHORTWAVE ROTATES THROUGH THE FLOW. ONCE AGAIN...THE STRONGER STORMS SHOULD ONCE AGAIN BE ACROSS NORTHERN AND EASTERN PORTIONS OF THE COUNTY WARNING AREA WHERE DEEPER MOISTURE AND HIGH CAPE VALUES AND LOWER LIFTED INDICES WILL BE FOUND. STORMS MAY NOT BE QUITE AS STRONG AS FRIDAY SINCE UPPER LEVEL SUPPORT IS A BIT LESS...BUT SOME ISOLATED STRONGER STORMS STILL LOOK POSSIBLE. STORMS MAY KEEP GOING INTO MUCH OF THE NIGHT ACROSS AREAS EAST OF THE BIGHORN RANGE SO WE RAISED POPS A BIT IN THAT VICINITY. IT LOOKS LIKE MORE OF THE SAME FOR SUNDAY AS IT LOOKS TO BE ANOTHER ACTIVE DAY OF SHOWERS AND THUNDERSTORMS. ONCE AGAIN...THE MOST NUMEROUS ACTIVITY WILL BE IN THE AFTERNOON OR EVENING HOURS BUT WE CAN NOT RULE ONE OUT AT ANY TIME. ONE DIFFERENCE WILL BE A SLIGHTLY STRONGER SHORTWAVE MOVING THROUGH NORTHERN PORTIONS OF THE AREA ALONG WITH MORE MOISTURE RETURN ACROSS EASTERN PORTIONS OF THE COUNTY WARNING AREA. THE NAM SHOWS PRECIPITABLE WATER LEVELS ONCE AGAIN CLIMBING TO AROUND 1 INCH IN THAT AREA. WITH SOME FAVORABLE JET DYNAMICS MOVING INTO THE AREA...STORMS COULD ONCE AGAIN GET FEISTY ONCE AGAIN. THE STORM PREDICTION CENTER HAS ISSUED A SLIGHT RISK FOR NORTHEASTERN PORTIONS OF THE AREA SO THIS WILL HAVE TO BE WATCHED CLOSELY. AS FOR MONDAY...IT COULD BE A LITTLE LESS ACTIVE WITH SOME SLIGHTLY DRIER AIR MOVING IN FROM THE WEST BUT A LOT OF UNCERTAINTY REMAINS SO WE MADE FEW CHANGES TO CONTINUITY. TEMPERATURES WILL REMAIN NEAR TO SOMEWHAT ABOVE NORMAL THROUGH THE PERIOD. .LONG TERM...TUESDAY THROUGH SATURDAY A WEATHER SYSTEM PASSES THROUGH MONTANA TUESDAY MORNING AND INTO NORTH DAKOTA BY TUESDAY NIGHT. A COLD FRONT GETS PUSHED INTO NORTHERN WY TUESDAY MORNING BUT IT WILL NOT MAKE MUCH OF A PUSH INTO CENTRAL WY. THE BOUNDARY MAY HELP AID THUNDERSTORM DEVELOPMENT TUE AFTERNOON IN THE NORTH/NORTHEAST ZONES. OTHERWISE ONLY ISOLATED ACTIVITY IS FORECAST OVER THE REST OF THE AREA TUE PM AND EVENING. LONG RANGE MODELS DEVELOP A RIDGE OVER THE AREA WEDNESDAY WHICH THEN TRANSITIONS TO A SW FLOW ALOFT FOR THURSDAY. ISOLATED STORMS ON WEDNESDAY WITH DRY WEATHER ON THURSDAY. MODELS DIFFER SOME NEXT FRIDAY AND SATURDAY WITH THE POSITION OF THE UPPER LEVEL HIGH PRESSURE CENTER. THE ECMWF MODEL PLACES THE CENTER IN COLORADO EAST OF THE MOUNTAINS FRIDAY AND THEN DEVELOPS AN ELONGATED HIGH FROM THE SOUTHERN PLAINS INTO THE DESERT SOUTHWEST SATURDAY WITH A WEST FLOW ALOFT OVER THE AREA. THE GFS MODEL PUTS THE UPPER HIGH CENTER OVER COLORADO FRIDAY AND THEN INTO EASTERN COLORADO SATURDAY. THE DIFFERENCES MAY SEEM SUBTLE BUT THE GFS MODEL ALLOWS MOISTURE BACK INTO OUR AREA FRIDAY/SATURDAY AT MID AND UPPER LEVELS. THE ECMWF IS SLOWER WITH THE RETURN OF MOISTURE AROUND THE UPPER HIGH. WILL SIDE WITH THE GFS FOR NOW AND BRING ISOLATED SHOWERS AND STORMS INTO THE MOUNTAINS AND FROM SW WY TO THE ZONES EAST OF THE BIGHORNS BOTH DAYS. AS FOR HIGH TEMPS...VERY WARM TO HOT FROM TUESDAY THROUGH SATURDAY WITH THURSDAY LOOKING TO BE THE HOTTEST DAY WHERE A FEW PLACES MAY SEE HIGH TEMPS AROUND 100 DEGREES. .AVIATION.../18Z ISSUANCE/ ACTIVE SHOWER AND THUNDERSTORM PERIOD ACROSS THE ENTIRE AREA THROUGH THE WEEKEND. EVEN THE NIGHTTIME AND MORNING PERIODS MAY SEE ISOLATED SHOWERS AND THUNDERSTORMS. ALL TERMINALS COULD BE IMPACTED AT ONE TIME OR ANOTHER. THE PEAK PERIODS WILL BE DURING THE AFTERNOON AND EVENING BUT ANY PERIOD COULD BE IMPACTED BY A THUNDERSTORM. THE MOST ACTIVE TO SEVERE AREA TODAY IS EXPECTED TO BE ACROSS THE FAR WEST INCLUDING KJAC BUT ALL TERMINALS WILL LIKELY HAVE THUNDERSTORMS AROUND AT ONE POINT OR ANOTHER. MOUNTAINS WILL BE OBSCURED AT TIMES AND MVFR CONDITIONS TO LOCAL IFR CONDITIONS WILL BE NOTED IN HEAVIER SHOWERS AND THUNDERSTORMS. .FIRE WEATHER... AN ACTIVE PERIOD OF SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE WEEKEND ACROSS THE AREA. THE PEAK PERIOD FOR STORMS WILL BE IN THE AFTERNOON AND EVENING BUT ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE DURING THE OVERNIGHT AND MORNING HOURS AS WELL. && .RIW WATCHES/WARNINGS/ADVISORIES...NONE. && SHORT TERM...SKRBAC LONG TERM...AR AVIATION...SKRBAC FIRE WEATHER...SKRBAC
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 906 AM MDT SAT JUL 6 2013 WYZ001>020-022>030-071200- 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- 906 AM MDT SAT JUL 6 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT SCATTERED TO NUMEROUS THUNDERSTORMS. SOME STORMS COULD BE STRONG IN THE AFTERNOON AND EVENING WITH HAIL...GUSTY WIND...AND HEAVY RAIN. A FEW STORMS COULD EVEN TURN SEVERE WITH LARGE HAIL AND DAMAGING WIND IN THE FAR WEST INCLUDING PARK...TETON AND LINCOLN COUNTIES. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY SUNDAY THROUGH MONDAY...ISOLATED TO SCATTERED THUNDERSTORMS. SOME STORMS COULD BE STRONG IN THE AFTERNOON AND EVENING. TUESDAY...WEDNESDAY AND FRIDAY...ISOLATED THUNDERSTORMS EACH AFTERNOON AND EVENING. .SPOTTER INFORMATION STATEMENT... SPOTTERS SHOULD REPORT HAIL SIZES...WIND DAMAGE OR HEAVY RAINFALL. TEAM RIVERTON
PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE RIVERTON WY
804 AM MDT SAT JUL 06 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0415 PM TSTM WND GST 6 N LUCERNE 43.82N 108.17W
07/05/2013 M60.00 MPH HOT SPRINGS WY EMERGENCY MNGR
60 MPH MEASURED WIND GUST CORRECTED
&&
SKRBACSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 1220 PM MDT SAT JUL 6 2013 WYZ001-012-013-061915- JACKSON HOLE-TETON AND GROS VENTRE MOUNTAINS- YELLOWSTONE NATIONAL PARK- 1220 PM MDT SAT JUL 6 2013 A LINE OF SHOWERS AND THUNDERSTORMS WILL MOVE REACH WESTERN TETON COUNTY AROUND 1230 PM...MOVING FROM THE SOUTHWEST TO THE NORTHEAST AT 35 TO 40 MPH. THE STORMS WILL MOVE THROUGH THE JACKSON AND TARGHEE AREAS BETWEEN 1250 PM AND 130 PM. EXPECT WIND GUSTS OF 40 MPH TO PRECEDE THE STORMS FOLLOWED BY LOCAL HEAVY DOWNPOURS AND POSSIBLY HAIL TO ONE INCH. JB
The Pocatello radar (KSFX), 158 km away, was scanning. The volume nearest the first event began at 19:18 UTC.
2 thunderstorm wind, 1 hail. Local standard time, as filed.
A wind gust to 72 mph was recorded at the Jackson Hole Mountain Resort.
Wind gusts estimated at 70 mph toppled a one foot diameter aspen tree at Star Valley Ranch.
A trained spotter at Star Valley Ranch reported hail up to the size of quarters.
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, July 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: 453396, 453398, 453399.