A strong surface pressure gradient and very strong mountain top wind combined to create hurricane force wind near Clark. Lesser speeds were measured in adjacent and nearby mountain areas.
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The episode as NWS RIW wrote it up.
A strong surface pressure gradient and very strong mountain top wind combined to create hurricane force wind near Clark. Lesser speeds were measured in adjacent and nearby mountain areas. NWS personnel measured frequent gusts of 75 to 95 mph near Clark with a peak gust measured at 110 mph. Sustained wind on Chief Joseph Pass hovered between 40 and 60 mph, while Beaver Rim had sustained speeds topping 40 mph.
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 Dec 2, 2:43 AM MST, 12 hours 17 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 243 AM MST SUN DEC 2 2007 .SHORT TERM...TODAY THROUGH TUESDAY NIGHT TEMPERATURES HAVE PLUMMETED IN THE BIG HORN BASIN AND PARTS OF THE WIND RIVER BASIN EARLY THIS MORNING AS SKIES PARTIALLY CLEARED AND SNOW COVER HELPS EFFICIENTLY RADIATE HEAT TO SPACE. THESE VERY COLD TEMPERATURES WILL KEEP THESE SAME AREAS IN THE COLD AND OUT OF THE WIND TODAY AS THE UPPER LEVEL PATTERN TRANSITIONS TO A STRONG AND RELATIVELY WARM WESTERLY ONE. THE WESTERLY FLOW IS SOMEWHAT MOIST AND WILL KEEP STRATUS CLOUDS ALONG WITH PERIODS OF LIGHT SNOW GOING OVER THE WESTERN MOUNTAINS THROUGH THE DAY. STRONG WEST WINDS ALONG THE WIND CORRIDOR (INTERSTATE 80 FROM JUST EAST OF ROCK SPRINGS EASTWARD TO CASPER) ARE EXPECTED TODAY AND CONTINUE THROUGH MONDAY WITH SUSTAINED WINDS OF 30 MPH WITH GUSTS TO 45 MPH POSSIBLE. HIGH WIND WARNING POTENTIAL CONTINUES FOR MAINLY THE ABSAROKA MOUNTAINS AND CODY FOOTHILLS TONIGHT INTO MONDAY MORNING. THE ONE CAVEAT MAY BE THE COLD AIR DOME IN THE BIG HORN BASIN PREVENTING THE WINDS FROM SURFACING IN THE CODY AREA. CURRENT TEMPERATURE AT CODY AIR 0 DEG F AND IT MAY TAKE SOME TIME TONIGHT TO ERODE THE COLD AIR ENOUGH TO ALLOW THE WIND MOMENTUM TO SURFACE. WILL LEAVE CURRENT HIGH WIND WATCH GOING AND LET DAY SHIFT DECIDE BASED ON WHAT OCCURS DURING THE LATE MORNING AND EARLY AFTERNOON. HIGH WIND POTENTIAL FOR THE EASTERN SLOPES OF THE ABSAROKA MOUNTAINS LOOKS GOOD WITH THE 06Z LOCALLY RUN WRF NMM PRODUCING A STABLE/CRITICAL LAYER NEAR MOUNTAIN TOP LEVEL TONIGHT AND MONDAY MORNING. STRONG WINDS IN THE LANDER FOOTHILLS NOT EXPECTED TO COME TO FRUITION WITH THE RELATIVELY WARM WESTERLY FLOW GOING RIGHT OVER THE TOP OF THE COLD DOME OF AIR AT THE SURFACE. LOCAL STRONG WIND GUSTS ALONG THE EASTERN SLOPES OF THE WIND RIVER RANGE LIKELY ABOVE ABOUT 7.5K...HOWEVER. MID-LEVEL MOISTURE IN THE WESTERLY FLOW IS EXPECTED TO INCREASE SUNDAY EVENING OVER THE WESTERN MOUNTAINS AND WITH THE SURFACE AND NEAR SURFACE COLD AIR IN PLACE...LIFT DUE TO ISENTROPIC UPGLIDE WILL PRODUCE AREAS OF LIGHT TO MODERATE SNOW FROM THE SALT RIVER AND WYOMING RANGES NORTHWARD INTO YELLOWSTONE NATIONAL PARK. A BRIEF BREAK IS ANTICIPATED MONDAY MORNING FOR MOST OF THE WEST WITH THE ONE EXCEPTIONS BEING OVER EXTREME NORTHWEST WY FROM THE TETONS NORTHWARD INTO YELLOWSTONE. 00Z GFS PRODUCING OVER SIX TENTHS OF AN INCH OF QPF MONDAY AFTERNOON FROM ABOUT JACKSON NORTHWARD. TIMING ALWAYS THE DIFFICULTY IN SUCH A FAST (160 KT) WESTERLY FLOW AND LATER SHIFTS WILL HAVE TO KEEP A CLOSE EYE ON THE POTENTIAL FOR HEAVY SNOW WITH THE PROGGED DEEP PACIFIC MOISTURE AND ANY SIGNIFICANT SHORT-WAVE MOVING THROUGH ON MONDAY. THE STRONG WESTERLY FLOW CONTINUES OVER THE REGION THROUGH TUESDAY NIGHT WITH PERIODS OF SNOW...POSSIBLY HEAVY AT TIMES...IN THE WESTERN MOUNTAINS. SKI AREAS WEST OF THE DIVIDE SHOULD DO QUITE WELL OVER THE NEXT SEVERAL DAYS WITH THIS TYPE OF PATTERN. AREAS EAST OF THE DIVIDE OUTSIDE OF THE BIG HORN MOUNTAINS WILL REMAIN DRY. AREAS IN THE BIG HORN AND WIND RIVER BASINS WILL REMAIN COLD WITH PATCHY FREEZING FOG OR LOW STRATUS CLOUDS REMAINING THROUGH THE PERIOD. .LONG TERM...WEDNESDAY THROUGH SUNDAY BETTER AGREEMENT WITH THE LONG RANGE MODELS WED THRU FRI. A WEATHER SYSTEM MOVES INTO THE PACIFIC NW STATES WED AND INTO THE NORTHERN ROCKIES WED NIGHT. THIS WILL LEAD TO A GOOD CHANCE OF SNOW FOR THE MTS AND A SLIGHT CHANCE OF SNOW AT THE LOWER ELEVATIONS...MAINLY WED NIGHT. THE SYSTEM MOVES THROUGH ON THURS. A CHANCE OF LT SNOW IN THE MORNING WITH IMPROVING CONDITIONS IN THE AFTERNOON FROM NW TO SE ACROSS THE REGION. MOSTLY DRY THURS NIGHT WITH SOME FLURRIES IN THE MTS. LITTLE BIT OF RIDGING FOR FRIDAY AS THE FLOW ALOFT BACKS TO THE SW. MODELS DEVELOP AN UPPER LOW ALONG OR JUST OFF THE CALIFORNIA COAST FRIDAY. NOT SURE HOW MUCH MOISTURE WILL FILTER INTO THE AREA FRI PM. PLUS THE MODELS WISH TO SEND A SHORTWAVE THROUGH THE FLOW FRI NIGHT. FOR NOW WILL KEEP LOW PRECIP CHANCE IN THE WESTERN MTS AND THE WESTERN VALLEYS. WILL HAVE LOW PRECIP CHANCES FOR FRI NIGHT PROVIDED THE SHORTWAVE MOVES THROUGH THE AREA. SATURDAY APPEARS TO BE A DRIER DAY FOR NOW WITH SOME MOUNTAIN SNOW SHOWERS POSSIBLE. GFS AND ECMWF MODELS DIFFER NEXT SUN WITH GFS HAVING THE LOW OFF SRN CALIFORNIA WHILE THE ECMWF PICKS IT UP AND MOVES IT INTO ARIZONA. IN THE NORTHERN STREAM...THE GFS BRINGS A SYSTEM ACROSS MONTANA WHILE THE ECMWF IS DEEPER WITH A TROUGH MOVING INTO THE NORTHERN ROCKIES AT 00Z MON. WILL HAVE PRECIP CHANCE IN THE MTS AND OVER THE NORTH ZONES. AS FOR TEMPS...SEASONAL HIGHS AND LOW THROUGH THE PERIOD. SOME AREAS WILL BE MILDER DUE TO SOME WIND AT TIMES. && .AVIATION... AREAS OF BKN-OVC MVFR CLOUD DECKS ALONG WITH PATCHY ICE FOG WILL PERSIST ACROSS THE AREA EARLY THIS MORNING...DISSIPATING 12Z-15Z. WEST TO SOUTHWEST WINDS WILL INTENSIFY OVER THE MOUNTAINS AND SOUTHERN WIND CORRIDOR THROUGH THE DAY CAUSING AREAS OF BLOWING SNOW AND MVFR/LOCAL IFR VISIBILITIES OVER THE MOUNTAINS AND RKS TO CPR ROUTES. && .FIRE WEATHER... AREAS OF LIGHT SNOW WILL CONTINUE OVER THE WESTERN MOUNTAINS TODAY. THE MAIN FORECAST CHALLENGE WILL BE STRONG WEST TO SOUTHWEST WINDS IN THE ABSAROKA MOUNTAINS AND CODY FOOTHILLS TONIGHT INTO MONDAY. ALSO...STRONG WEST WINDS IN THE WIND CORRIDOR FROM MUDDY GAP EASTWARD TO CASPER ARE EXPECTED TODAY THROUGH AT LEAST MONDAY AFTERNOON. WINDY CONDITIONS ARE EXPECTED FOR NEARLY ALL MOUNTAIN LOCATIONS TODAY THROUGH MONDAY NIGHT. SIGNIFICANT SNOWFALL IS POSSIBLE IN THE NORTHWEST MOUNTAINS MONDAY AFTERNOON AND MONDAY NIGHT. && .RIW WATCHES/WARNINGS/ADVISORIES... HIGH WIND WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING FOR WYZ002-003. && SHORT TERM...CHURCH LONG TERM...AR AVIATION...AEM FIRE WEATHER...CHURCH
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 500 AM MST SUN DEC 2 2007 WYZ001>020-022>030-031300- 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- 500 AM MST SUN DEC 2 2007 ...HIGH WIND WATCH CODY FOOTHILLS AND ABSAROKA MOUNTAINS TONIGHT AND MONDAY MORNING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT WEST WINDS OF 15 TO 25 MPH WITH GUSTS TO 30 MPH ARE EXPECTED IN THE RED DESERT EASTWARD INTO NATRONA COUNTY TODAY CREATING AREAS OF BLOWING AND DRIFTING SNOW. VERY STRONG WEST WINDS ARE POSSIBLE TONIGHT ALONG THE EASTERN SLOPES OF THE ABSAROKA MOUNTAINS AND ADJACENT CODY FOOTHILLS. AREAS OF LIGHT SNOWFALL ARE EXPECTED IN THE WESTERN MOUNTAINS TODAY...BECOMING MORE WIDESPREAD AND POSSIBLY HEAVIER TONIGHT. TRAVELLERS SHOULD BE PREPARED FOR WINTER DRIVING CONDITIONS. CHECK THE LATEST ROAD REPORT BEFORE VENTURING OUT. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY VERY STRONG WEST WINDS ARE POSSIBLE ALONG THE EASTERN SLOPES OF THE ABSAROKA MOUNTAINS AND ADJACENT FOOTHILLS THROUGH MONDAY MORNING. STRONG WEST WINDS ARE EXPECTED TO CONTINUE IN THE JEFFREY CITY AND MUDDY GAP AREA EASTWARD TO CASPER THROUGH MONDAY NIGHT. SIGNIFICANT SNOWFALL IS POSSIBLE MONDAY AFTERNOON THROUGH MONDAY NIGHT IN THE WESTERN MOUNTAINS. A HIGH WIND WATCH HAS BEEN POSTED FOR THE CODY FOOTHILLS AND THE EAST SLOPES OF THE ABSAROKA MOUNTAINS TONIGHT AND MONDAY MORNING. THE POTENTIAL FOR WEST WINDS OF 40 MPH WITH GUSTS TO 60 MPH EXISTS FROM MEETEETSE TO CODY AND CLARK WITH WEST WINDS OF 50 MPH WITH GUSTS TO 75 MPH ALONG THE EAST SLOPE OF THE ABSAROKA MOUNTAINS INCLUDING THE CHIEF JOSEPH HIGHWAY TONIGHT INTO MONDAY MORNING. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT SNOWFALL AMOUNTS AND STRONG WIND SPEEDS TONIGHT AND MONDAY. THANK YOU. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
3 high wind. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2007Every state in 2007This day in weather historyWarnings in Wyoming, December 2007
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: 65486, 65484, 65485.