Two hikers climbing Grand Teton were caught in a winter storm on August 29. On the summit of Grand Teton, two feet of snow was deposited between August 29-31.
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The episode as NWS RIW wrote it up.
Two hikers climbing Grand Teton were caught in a winter storm on August 29. On the summit of Grand Teton, two feet of snow was deposited between August 29-31. The climbers sought refuge inside a dry cave until skies cleared on August 31. However, one of the climbers was seriously injured when he fell during the descent.
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 29, 2:45 AM MST, 9 hours 15 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 345 AM MDT THU AUG 29 2003 .TODAY THROUGH SUNDAY NIGHT... ETA AND THE GFS HAVE COME TO MORE OF AN AGREEMENT WITH UPCOMING TIMING AND STRENGTH OF WEATHER SYSTEM TO AFFECT WY DURING THE NEXT COUPLE OF DAYS. SURFACE COLD FRONT HAS ALREADY PUSHED SOUTH ACROSS RKS. LEAD SHORTWAVE DIVING DOWN FROM MONTANA HAS PRODUCED SOME THUNDERSHOWER ACTIVITY OVER THE NORTHERN TIER OF WY THIS EVENING. MAIN SHORTWAVE IN NORTHERN STREAM NOW PUSHING SOUTH ACROSS CENTRAL MONTANA. THIS FEATURE IS PROGGED BY THE MODELS TO MOVE SOUTH TO NW WY TODAY. MEANWHILE A VIGOROUS VORT MAX NOW PRODUCING CONSIDERABLE LIGHTNING OVER THE OREGON/CA/NEV TRIPLE POINT IS PROGGED BY THE MODELS TO MOVE EAST TO SOUTHERN IDAHO TODAY AND TO WESTERN WY BY THIS EVENING AND THEN FINALLY WILL STRENGTHEN OVER SOUTHWEST WY BY SATURDAY MORNING WHERE MOST OF THE RAINFALL SHOULD OCCUR TONIGHT. AS THE NORTHERN STREAM TROUGH WASHES OUT...THE PACIFIC SYSTEM WILL BECOME THE PREDOMINANT FEATURE. DYNAMICS ASSOCIATED WITH THIS FEATURE ALL SEEM TO COME TOGETHER TONIGHT THROUGH SATURDAY WITH A JET COUPLET FROM THE TWO JET STREAMS THIS EVENING...GOOD DIV Q TONIGHT THROUGH SATURDAY...GOOD ISENTROPIC LIFT WITH H5 FLOW FROM THE SOUTH OVER-RUNNING ENE SFC WINDS...A MOIST SURFACE UPSLOPE FLOW EAST OF THE DIVIDE...AS WELL AS LIMITED UPPER DIFFLUENT FLOW AND A COLD POOL ALOFT. SCATTERED THUNDERSTORMS SHOULD OCCUR MOST AREAS TODAY. THE LOWER AIRMASS WILL STABILIZE IN THE NE QUARTER OF THE CWA TONIGHT THROUGH SATURDAY WITH MAINLY ELEVATED CONVECTION EXPECTED THERE SATURDAY WHERE GOOD WIND SHEER ALOFT SHOULD SUPPORT ISOLD TSRA ESPECIALLY IN THE BIG HORN MOUNTAINS. ELSEWHERE THE COLD POOL ALOFT AND THE SURFACE CONVERGENCE NEAR THE FRONT WILL SUPPORT A GOOD CHANCE OF THUNDERSTORMS SATURDAY...ESPECIALLY WEST OF THE DIVIDE. THE BULK OF THE RAINFALL CWA WIDE SHOULD OCCUR TONIGHT THROUGH SATURDAY EVENING. SATURDAY NIGHT THE PRECIP WILL END FROM WEST TO EAST WITH BOTH THE GFS/ETA SLOWING THE EXITING OF THIS SYSTEM. PATCHY FOG SHOULD FORM IN THE CENTRAL BASINS SUNDAY MORNING WITH ENOUGH RADIATIONAL COOLING TO OCCUR TO LOWER THE TEMPS DOWN TO THE ELEVATED DEW POINTS. WILL KEEP ISOLD TSRA IN THE NW SUNDAY WITH NEGATIVE LIFTED INDICES THERE. .MONDAY THROUGH THURSDAY... HIGH PRESSURE WILL BUILD OVER THE AREA THROUGH WEDNESDAY THEN BEGIN TO BREAK DOWN ON THURSDAY AS PACIFIC MOISTURE MOVES IN FROM THE WEST. THIS WILL BRING A WARMING TREND AFTER MONDAY MORNING WHICH SHOULD BE THE COLDEST MORNING ACROSS THE AREA SINCE LAST JUNE. SOME UPPER LEVEL MOISTURE WILL RETURN TO THE SOUTH LATE WEDNESDAY AND FOR NOW HAVE INCREASED CLOUDS LATE WEDNESDAY THEN BRING IN SOME SHOWERS AND THUNDERSTORMS TO THE WEST AND SOUTHWEST SPREADING EAST IN THE EVENING THURSDAY. HAVE MADE ONLY MINOR CHANGES TO DAY TIME TEMPERATURES OTHERWISE NOT MUCH CHANGES NEEDED TO THE SUNDAY THROUGH THURSDAY PERIODS. C.BAKER .RIW...NONE.
WYZ001>020-022>030-301101- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 500 AM MDT FRI AUG 29 2003 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT AN UPPER LEVEL WEATHER SYSTEM WILL DEVELOP OVER WYOMING TODAY. THE COMBINATION OF MOISTURE FROM THIS WEATHER FEATURE ALONG WITH MUCH COOLER AIR ALREADY IN PLACE FROM A COLD FRONT THAT PUSHED SOUTH ACROSS WYOMING LAST NIGHT WILL LEAD TO A GOOD CHANCE OF A COLD RAIN OVER MUCH OF THE HIGHER MOUNTAINS OF WYOMING TONIGHT. HIKERS AND CAMPERS IN THE HIGHER TERRAIN OF WYOMING SHOULD PREPARE FOR MUCH COLDER AND WETTER CONDITIONS TONIGHT BY DRESSING APPROPRIATELY. SOME OF THE HIGHER MOUNTAINS WILL DIP INTO THE MID AND UPPER 30S TONIGHT. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THE COLD AND WET WEATHER WILL PERSIST THROUGH SATURDAY EVENING IN THE MOUNTAINS. MANY OF THE HIGHER MOUNTAIN LOCATIONS REMAINING IN THE 40S DURING THE DAY ON SATURDAY. THIS SHOULD BE THE COOLEST AIRMASS TO MOVE INTO THE AREA SINCE JUNE. .SPOTTER INFORMATION STATEMENT... NO SPOTTER ACTIVATION WILL BE NEEDED TODAY AND TONIGHT.
The national radar mosaic for the moment the first event began.
1 winter storm. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2003Every state in 2003This day in weather historyWarnings in Wyoming, August 2003
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: 5334856.