Scattered strong thunderstorms formed across western and central Wyoming during the afternoon hours.
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.
Scattered strong thunderstorms formed across western and central Wyoming during the afternoon hours.
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 Aug 28, 2:35 AM MST, 10 hours 35 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 335 AM MDT SAT AUG 28 2010 .SHORT TERM...TODAY THROUGH MONDAY NIGHT A CLOSED LOW PROPAGATING EAST ACROSS CENTRAL CANADA IS SWEEPING A TRAILING VORT LOBE EAST ACROSS WYOMING WHICH IS PRESENTLY PRODUCING AREAS OF MODERATE RAIN AND LOCALIZED HEAVY RAINFALL ACROSS SOUTHWEST AND CENTRAL WYOMING. AN ASSOCIATED COLD FRONT TRACKED SOUTH ACROSS WYOMING FRIDAY EVENING. THE NAM HAS BEEN ADVERTISING BETWEEN ONE AND TWO INCHES OF RAINFALL BY 12Z THIS MORNING FOR THE PAST COUPLE OF DAYS. UPDATED THE QPF TO INDICATE A SWATH OF UP TO .35 INCHES OF PRECIP ACROSS THE SOUTHWEST QUARTER OF THE CWA THROUGH 12Z THIS MORNING. PW VALUES FOR RIW ARE .91 INCHES. ALL THIS PRECIP IS FALLING OUT OF THE SUBTROPICAL CONNECTION STREAMING NORTH WITHIN OUR MONSOON FEED OUT AHEAD OF THE PACIFIC MOISTURE MORE DIRECTLY ASSOCIATED WITH A STRONG PACIFIC TROUGH SITUATED ALONG THE PACIFIC COAST TRAILING FROM A WELL DEFINED CLOSED LOW OVER NORTHERN ALBERTA. THE FLOW WILL BUCKLE TODAY WITH THE STEERING WINDS BACKING TO MORE OF A SW FLOW WITH THE TROUGH ALONG THE PACIFIC COAST AMPLIFYING. THIS TROUGH WILL EJECT A SERIES OF VORT LOBES ACROSS THE AREA TODAY THROUGH SUNDAY NIGHT. TODAY WILL FEATURE A FAIRLY UNSTABLE AIRMASS ALONG WITH -3.5 LIFTED INDICES OVER NW WY WHERE THE GREATEST INSTABILITY WILL BE. THIS IS WHERE THE BULK OF THE SHOWER AND THUNDERSTORM ACTIVITY OVER SOUTHWEST WY WILL PROPAGATE TO LATER TODAY. IN ADDITION...Q VECTOR FORCING WILL MOVE INTO NW WY TONIGHT AS SOME OF THE STRONGER VORT ENERGY CLIPS THE REGION. SURFACE CYCLOGENESIS WILL OCCUR ALONG THE STALLED ANAFRONT FRONT TODAY ADDING TO THE SURFACE CONVERGENCE. THE ASSOCIATED H7 LOW WILL BE LOCATED OVER WESTERN MONTANA WHICH WILL HELP ENHANCE PRECIP LONG AFTER MIDNIGHT SATURDAY NIGHT AND INTO SUNDAY MORNING IN NW WY. WITH Q VECTOR FORCING...BETTER VORT ENERGY AND THE CLOSE PROXIMITY OF THE H7 LOW TO NW WY...LIKELY POPS ARE INDICATED IN NW WY FROM THIS AFTERNOON ALL THE WAY THROUGH SUNDAY NIGHT WITH LESSER POPS ELSEWHERE. TWO PASSING JET MAXES WILL ADD TO THE LIFT SUNDAY AND SUNDAY NIGHT AS WELL. SOUTHWEST WINDS WILL BLOW AT 30 TO 40 MPH ACROSS PORTIONS OF THE SOUTHERN WIND CORRIDOR SUNDAY AS THE SOUTHWESTERLY GRADIENT TIGHTENS. THE GFS HAS THE MAIN TROUGH TRACKING ACROSS CENTRAL WYOMING AROUND 18Z MONDAY. THE ASSOCIATED COLD FRONT WILL PUSH THROUGH WYOMING SUNDAY NIGHT. 9MB 3 HOURLY SURFACE PRESSURE RISES ARE PROGGED BEHIND THE FRONT OVER JOHNSON COUNTY WHERE POST FRONTAL NW WINDS WILL INCREASE SUNDAY EVE. STRONG Q VECTOR FORCING OF -28K/M^2/1E16S IS SLATED FOR MONDAY WITH LIKELY POPS SPREADING EAST ACROSS THE REST OF NORTHERN WY MONDAY WITH HIGH CHANCES ELSEWHERE. AFTER THE TROUHPA PRECIP WILL DISSIPATE MONDAY NIGHT WITH SCATTERED LINGERING SHOWERS IN NORTHERN WY. THE LONG WAVE TROUGH WILL BEGIN TO REESTABLISH ITSELF BY MONDAY NIGHT ALONG THE PACIFIC COAST. THIS WILL DELAY THE COLDER AIR EARLIER ANTICIPATED WITH MONDAYS TROUHPA. THE GFS AND THE COLDER NAM HAVE DELAYED AND MODERATED THE COLDER AIR MOVING IN FROM THE WEST WITH THE COLDEST AIR NOW SLATED FOR 12Z TUESDAY INSTEAD OF 12Z MONDAY INDICATED BY EARLIER RUNS. THE GFS NOW INDICATES AN H7 TEMP OF -1C FOR 12Z TUE IN NW WY WITH THE COLDER NAM GOING WITH -3.5C. THE COLDEST AIR WILL ARRIVE AFTER THE BULK OF THE PRECIP MOVES EAST OF THE AREA SO ONLY LIGHT AMOUNTS OF SNOW ARE EXPECTED OVER THE HIGHER MOUNTAINS MONDAY MORNING THROUGH LATE MONDAY NIGHT IN FAR WESTERN WY. .LONG TERM...TUESDAY THROUGH SATURDAY COOL CYCLONIC FLOW WITH LOW CHANCES OF PRECIPITATION...SNOW SHOWERS POSSIBLE ABOVE 9000 FEET...REMAIN ACROSS THE NORTH TUESDAY AND TUESDAY NIGHT. UPPER RIDGE BUILDS IN THROUGH WEDNESDAY WITH MOSTLY DRY WEATHER AND A WARMING TREND THROUGH THE END OF THE WEEK. COUPLE OF MORE SHORTWAVES FOLLOWS MONDAY NIGHT/S SHORTWAVE IN CYCLONIC FLOW ACROSS THE NORTH TUESDAY INTO WEDNESDAY MORNING WITH GFS AND ECMWF IN GOOD OVERALL AGREEMENT TONIGHT ON TIMING. FIRST FAST-MOVING SHORTWAVE TIMED MOVE EAST ACROSS MONTANA AND NORTHERN WYOMING TUESDAY AFTERNOON WITH TRAILING SHORTWAVE IN NW FLOW ACROSS EASTERN MONTANA AND NORTHEAST WYOMING WEDNESDAY MORNING. A DRY AND COOL WESTERLY FLOW PREVAILS ACROSS THE SOUTHERN TWO-THIRDS OF WYOMING. WARMER AIR BEGINS TO PUSH IN WEDNESDAY AFTERNOON BEHIND EXITING SHORTWAVE AS UPPER RIDGE BUILDS IN. FOUR CORNERS HIGH WITH UPPER RIDGE EXTENDING INTO CANADIAN ROCKIES BRINGS DRY WEATHER WITH A RETURN TO ABOVE NORMAL TEMPERATURES THURSDAY. UPPER LOW SLOWLY PUSHES INTO THE NORTHWEST U.S. FRIDAY AND SATURDAY PER PREFERRED LESS PROGRESSIVE ECMWF...SETTING UP SOUTHWEST FLOW...DRY...WARM AND BREEZY TO WINDY CONDITIONS OVER MUCH OF THE AREA AND POSSIBLE CRITICAL FIRE WEATHER CONDITIONS. && .AVIATION... DIGGING TROUGH OFF THE OREGON/CALIFORNIA COAST IS SLOWLY SHUNTING THE MONSOON MOISTURE PLUME TO THE EAST. SUCCESSION OF SHORTWAVES KEPT CONVECTION GOING THROUGH FRIDAY EVENING AND INTO THE EARLY SATURDAY MORNING HOURS. LAST OF THESE WAVES SHOULD CLEAR CENTRAL WYOMING AROUND 10Z-12Z TODAY. THERE THEN APPEARS TO BE A BREAK THIS MORNING BEFORE CONVECTION FIRES AGAIN AROUND NOON IN THE SOUTHWEST AND EARLY THIS AFTERNOON ELSEWHERE. WEDGE OF DRIER AIR AHEAD OF THE INCOMING TROUGH SHOULD BEGIN TO LIMIT CONVECTION ACROSS THE WEST BY EARLY THIS EVENING. ENOUGH MOISTURE NOW IN PLACE TO GENERATE MVFR CONDITIONS TODAY WITH THUNDERSTORMS AND SHOWERS WEST OF THE DIVIDE. TO THE EAST...DRIER CONDITIONS AND DOWNSLOPING SOUTHWEST FLOW SHOULD ALLOW FOR MAIN HAZARD TO BE GUSTY OUTFLOW WIND OF 30KT+. OTHERWISE...VFR CONDITIONS TO PERSIST THROUGH THE PERIOD. && .FIRE WEATHER... A STRONG PACIFIC TROUGH OF LOW PRESSURE WILL TRACK EAST TOWARD WYOMING THROUGH EARLY NEXT WEEK. THIS WILL RESULT IN A TREND TOWARD COOLER AND WETTER WEATHER THROUGH MONDAY NIGHT. THE BULK OF THE PRECIPITATION WILL BE OVER SOUTHWEST WYOMING THIS MORNING BUT WILL THEN TREND TOWARD NORTHWEST WYOMING THIS AFTERNOON THROUGH EARLY NEXT WEEK WHERE NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED. SCATTERED SHOWERS AND THUNDERSTORMS WILL ALSO FALL ELSEWHERE. VERY LIGHT AMOUNTS OF SNOW ARE EXPECTED OVER THE HIGHER MOUNTAINS MONDAY MORNING THROUGH MONDAY EVENING. ANY LIGHTNING THAT OCCURS FROM THIS WEEKENDS THUNDERSTORM ACTIVITY WILL BE ACCOMPANIED BY SIGNIFICANT RAINFALL. SOUTHWEST WINDS OF 20 TO 30 MPH WILL BLOW ACROSS THE SOUTHERN WIND CORRIDOR DURING THE DAYLIGHT HOURS THROUGH MONDAY WITH THE STRONGEST WINDS EXPECTED SUNDAY. && .RIW WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM...LIPSON LONG TERM...AEM AVIATION...CNJ FIRE WEATHER...LIPSON
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 1157 AM MDT SAT AUG 28 2010 WYZ001>020-022>030-290000- 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- 1157 AM MDT SAT AUG 28 2010 ...SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 6 PM FOR MUCH OF WESTERN WYOMING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT THERE WILL BE A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS TODAY AS AN UNSETTLED WEATHER PATTERN TAKES SHAPE OVER THE WESTERN UNITED STATES. THE MAJORITY OF THE SHOWERS AND THUNDERSTORMS WILL OCCUR IN WESTERN WYOMING WHERE THE STORMS ARE LIKELY THROUGH THIS EVENING. SOME OF THE STORMS WEST OF THE DIVIDE MAY BE SEVERE WITH LARGE HAIL...DAMAGING WIND...HEAVY RAIN AND FREQUENT LIGHTNING... ESPECIALLY THIS AFTERNOON AND EVENING. STORMS EAST OF THE DIVIDE MAY CONTAIN SMALL HAIL...GUSTY WIND OVER 40 MPH...HEAVY RAIN AND FREQUENT LIGHTNING. TAKE PRECAUTION NOW FOR AN ACTIVE DAY OF THUNDERSTORMS. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THERE WILL BE A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS SUNDAY THROUGH MONDAY AS AN UNSETTLED WEATHER PATTERN CONTINUES AS A PACIFIC TROUGH APPROACHES WYOMING. THE MAJORITY OF THE SHOWERS AND THUNDERSTORMS WILL OCCUR IN NORTHWESTERN WYOMING WHERE THE STORMS ARE LIKELY. THE BIGGEST THREAT WITH THESE STORMS WILL BE SMALL HAIL. GUSTY WINDS WILL ACCOMPANY THE STORMS ON SUNDAY EAST OF THE DIVIDE. THE AIRMASS WILL STEADILY BECOME COLDER THROUGH EARLY NEXT WEEK AND WILL BRING AN INCH OR LESS OF SNOWFALL TO THE WESTERN MOUNTAINS ABOVE 8000 FEET SUNDAY NIGHT AND MONDAY NIGHT. STAY TUNED FOR FURTHER STATEMENTS AND UPDATES AS THIS STORM STRENGTHENS AND MOVES THROUGH WESTERN AND CENTRAL WYOMING SUNDAY NIGHT AND MONDAY. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT HAIL...WIND GUSTS OVER 40 MPH AND ANY RAINFALL ACCUMULATION ABOVE ONE QUARTER OF AN INCH. THANK YOU. TEAM RIVERTON
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 1220 PM MDT SAT AUG 28 2010 WYZ001-281930- YELLOWSTONE NATIONAL PARK- 1220 PM MDT SAT AUG 28 2010 SHOWERS AND THUNDERSTORMS CONTINUE TO MOVE NORTHEAST THROUGH YELLOWSTONE NATIONAL PARK THIS AFTERNOON. SOME SHOWER ACTIVITY MAY CONTAIN HAIL UP TO A HALF INCH...GUSTY WIND OF 45 TO 50 MPH...AND FREQUENT LIGHTNING. A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR YELLOWSTONE NATIONAL PARK UNTIL 6 PM THIS EVENING. A WATCH MEANS THAT CONDITIONS ARE FAVORABLE FOR SEVERE THUNDERSTORMS DEVELOPMENT THIS AFTERNOON. SEVERE THUNDERSTORMS MAY CONTAIN LARGE HAIL OF AN INCH OR LARGER AND WIND IN EXCESS OF 55 MPH. PEOPLE ENJOYING OUTDOOR ACTIVITIES SHOULD FIND A STURDY INDOOR SHELTER IF STORMS APPROACH THEIR AREA AND REMAIN IN THAT LOCATION UNTIL STORM ACTIVITY HAS PASSED. BRANHAM
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 1245 PM MDT SAT AUG 28 2010 WYZ014-015-017>019-026-281930- GREEN MOUNTAINS AND RATTLESNAKE RANGE WY-LANDER FOOTHILLS WY-UPPER GREEN RIVER BASIN WY-WIND RIVER BASIN WY-WIND RIVER MOUNTAINS EAST WY-WIND RIVER MOUNTAINS WEST WY- 1245 PM MDT SAT AUG 28 2010 ...SIGNIFICANT WEATHER ADVISORY FOR EXTREME NORTHERN SWEETWATER... SOUTHEASTERN SUBLETTE AND SOUTHERN FREMONT COUNTIES UNTIL 130 PM MDT... AT 1242 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 7 MILES WEST OF STATE HWY 28 MILE MARKER 30... OR 25 MILES NORTHEAST OF FARSON...MOVING NORTHEAST AT 40 MPH. HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS STORM...ALONG WITH FREQUENT DANGEROUS LIGHTNING. THIS STORM WILL BE NEAR... STATE HWY 28 MILE MARKER 30 AROUND 1250 PM MDT. SOUTH PASS REST AREA AROUND 1255 PM MDT. STATE HWY 28 MILE MARKER 40 AROUND 100 PM MDT. SOUTH PASS CITY AROUND 105 PM MDT. ATLANTIC CITY AROUND 110 PM MDT. STATE HWY 28 MILE MARKER 50 AROUND 115 PM MDT. STATE HWY 28 MILE MARKER 60 AND RED CANYON AROUND 125 PM MDT. THIS STORM MAY ALSO IMPACT THE NORTH FORK WILDFIRE ON THE EASTERN SLOPES OF THE WIND RIVER MOUNTAINS. A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 600 PM MDT SATURDAY EVENING FOR NORTHWESTERN WYOMING. REPORT HAZARDOUS WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN RIVERTON AT 1-800-211-1448. LAT...LON 4314 10899 4234 10822 4223 10906 4253 10936 TIME...MOT...LOC 1845Z 236DEG 35KT 4238 10905 BRANHAM
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
114 PM MDT SAT AUG 28 2010
WYZ001-012>015-023>025-282000-
JACKSON HOLE WY-SALT RIVER AND WYOMING RANGES WY-STAR VALLEY WY-TETON
AND GROS VENTRE MOUNTAINS WY-UPPER GREEN RIVER BASIN FOOTHILLS
WY-WIND RIVER MOUNTAINS EAST WY-WIND RIVER MOUNTAINS WEST
WY-YELLOWSTONE NATIONAL PARK WY-
114 PM MDT SAT AUG 28 2010
...SIGNIFICANT WEATHER ADVISORY FOR EXTREME NORTHWESTERN FREMONT
COUNTY IN CENTRAL WYOMING...AND TETON COUNTY IN NORTHWEST WYOMING...
AND NORTHWESTERN SUBLETTE AND NORTHWESTERN LINCOLN COUNTIES IN WEST
CENTRAL WYOMING UNTIL 200 PM MDT...
AT 112 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 8 MILES NORTH OF U.S. HWY 26/89 MILE MARKER
120...OR 17 MILES SOUTHWEST OF JACKSON...MOVING NORTHEAST AT 30 MPH.
HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 45 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN AND FREQUENT
DANGEROUS LIGHTNING.
THIS STORM WILL BE NEAR...
RAFTER J RANCH AND TETON PASS AROUND 135 PM MDT.
WILSON...U.S. HWY 26/89 MILE MARKER 150 AND STATE HWY 22 MILE MARKER
10 AROUND 140 PM MDT.
TETON COUNTY FAIRGROUNDS AND JACKSON AROUND 145 PM MDT.
TETON VILLAGE AND RENDEZVOUS PEAK AROUND 150 PM MDT.
GROS VENTRE JCT AND U.S. HWY 26/89 MILE MARKER 160 AROUND 155 PM MDT.
MOOSE...PHELPS LAKE AND KELLY AROUND 200 PM MDT.
THESE STORMS ARE ON TRACK TO IMPACT THE BULL...CRYSTAL AND GRAVEL
WILDFIRES.
IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.
BRIEF HEAVY RAIN...WHICH MAY FLOOD LOW LYING AREAS SUCH AS DITCHES
AND UNDERPASSES...IS ALSO LIKELY. DO NOT DRIVE YOUR VEHICLE ON A
FLOODED ROADWAY.
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 600 PM MDT
SATURDAY EVENING FOR NORTHWESTERN WYOMING.
REPORT HAZARDOUS WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN
RIVERTON AT 1-800-211-1448.
LAT...LON 4360 11106 4429 11085 4386 11004 4367 10994
4271 11078 4313 11106
TIME...MOT...LOC 1913Z 212DEG 27KT 4330 11098
BRANHAMSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 116 PM MDT SAT AUG 28 2010 WYZ014-015-017>019-282000- GREEN MOUNTAINS AND RATTLESNAKE RANGE WY-LANDER FOOTHILLS WY-WIND RIVER BASIN WY-WIND RIVER MOUNTAINS EAST WY-WIND RIVER MOUNTAINS WEST WY- 116 PM MDT SAT AUG 28 2010 ...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL FREMONT COUNTY UNTIL 200 PM MDT... AT 112 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 7 MILES NORTH OF SOUTH PASS CITY...OR 19 MILES SOUTH OF LANDER...MOVING NORTHEAST AT 40 MPH. HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THIS STORM...ALONG WITH FREQUENT DANGEROUS LIGHTNING. THIS STORM WILL BE NEAR... RED CANYON AND STATE HWY 28 MILE MARKER 60 AROUND 125 PM MDT. U.S. HWY 287 MILE MARKER 70 AND HWY JCT 287 AND 28 AROUND 135 PM MDT. HUDSON AROUND 150 PM MDT. A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 600 PM MDT SATURDAY EVENING FOR NORTHWESTERN WYOMING. REPORT HAZARDOUS WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN RIVERTON AT 1-800-211-1448. LAT...LON 4311 10875 4260 10815 4236 10879 4259 10900 TIME...MOT...LOC 1916Z 221DEG 34KT 4259 10877 BRANHAM
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RIVERTON WY
146 PM MDT SAT AUG 28 2010
WYZ017>019-030-282015-
EAST SWEETWATER COUNTY WY-GREEN MOUNTAINS AND RATTLESNAKE RANGE
WY-LANDER FOOTHILLS WY-WIND RIVER BASIN WY-
146 PM MDT SAT AUG 28 2010
...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN SWEETWATER AND
SOUTHEASTERN FREMONT COUNTIES UNTIL 215 PM MDT...
AT 148 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM SWEETWATER STATION
TO 13 MILES SOUTHWEST OF SWEETWATER STATION TO 14 MILES EAST OF
OREGON BUTTES...AND MOVING NORTHEAST AT 35 MPH.
HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 40 MPH ARE
EXPECTED WITH THESE STORMS...ALONG WITH HEAVY RAIN AND FREQUENT
DANGEROUS LIGHTNING.
THESE STORMS WILL BE NEAR...
GAS HILLS AROUND 155 PM MDT.
STATE HWY 135 MILE MARKER 30 AND U.S. HWY 287 MILE MARKER 40 AROUND
200 PM MDT.
SWEETWATER STATION AROUND 205 PM MDT.
STATE HWY 135 MILE MARKER 20...SAND DRAW AND GAS HILLS RD MILE MARKER
40 AROUND 210 PM MDT.
BRIEF HEAVY RAIN...WHICH MAY FLOOD LOW LYING AREAS SUCH AS DITCHES
AND UNDERPASSES...IS ALSO LIKELY. DO NOT DRIVE YOUR VEHICLE ON A
FLOODED ROADWAY.
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 600 PM MDT
SATURDAY EVENING FOR NORTHWESTERN WYOMING.
REPORT HAZARDOUS WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN
RIVERTON AT 1-800-211-1448.
LAT...LON 4221 10761 4216 10839 4210 10875 4278 10834
4288 10801 4295 10756
TIME...MOT...LOC 1947Z 210DEG 32KT 4252 10824 4238 10834
4224 10858
BRANHAMSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 203 PM MDT SAT AUG 28 2010 WYZ001-282030- YELLOWSTONE NATIONAL PARK WY- 203 PM MDT SAT AUG 28 2010 ...SIGNIFICANT WEATHER ADVISORY FOR WESTERN PARK AND NORTHERN TETON COUNTIES IN NORTHWEST WYOMING UNTIL 230 PM MDT... AT 200 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 13 MILES NORTHWEST OF GIBSON MEADOWS...OR 22 MILES NORTH OF JUDKINS...MOVING NORTHEAST AT 30 MPH. HAIL UP TO THE SIZE OF PENNIES AND WIND GUSTS UP TO 45 MPH ARE EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN AND FREQUENT DANGEROUS LIGHTNING. THIS STORM WILL BE NEAR... MYSTIC FALLS AND OLD FAITHFUL AROUND 230 PM MDT. IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A STURDY BUILDING. BRIEF HEAVY RAIN...WHICH MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND UNDERPASSES...IS ALSO LIKELY. DO NOT DRIVE YOUR VEHICLE ON A FLOODED ROADWAY. A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 600 PM MDT SATURDAY EVENING FOR NORTHWESTERN WYOMING. REPORT HAZARDOUS WEATHER TO THE NATIONAL WEATHER SERVICE OFFICE IN RIVERTON AT 1-800-211-1448. LAT...LON 4495 11072 4431 11029 4414 11104 4459 11104 TIME...MOT...LOC 2003Z 216DEG 28KT 4426 11110 BRANHAM
The Riverton/Lander radar (KRIW), 92 km away, was scanning. The volume nearest the first event began at 20:09 UTC.
1 hail, 1 thunderstorm wind. Local standard time, as filed.
The Hot Springs County emergency manager reported penny sized hail along State Highway 120 approximately 23 miles northwest of Thermopolis.
A strong thunderstorm produced a wind gust to 60 mph at Rock Springs-Sweetwater County Airport.
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, August 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: 251855, 251853.