Favorable conditions led to a mountain wave event in some locations across northwest Wyoming. Enhanced northwest flow led to very high wind channeling down the Wind River Valley.
Every event with a place to put it; 6 filed by county or forecast zone are drawn at its center, in a lighter ring. 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.
Favorable conditions led to a mountain wave event in some locations across northwest Wyoming. Enhanced northwest flow led to very high wind channeling down the Wind River Valley. Mountain locations experienced frequent gusts in excess of 74 mph with peak gusts of 83 to 94 mph. Winds in the lower elevations were sustained between 40 and 48 mph with gusts of 63 to 71 mph recorded. Damage included a downed fence, blown-out window, and a collapsed shed in the area between Riverton and Pavillion. The wind also toppled an 80-foot tree and dislodged roof shingles in Dubois. The tree was downed during the afternoon and blocked westbound lanes on Ramshorn Street for several 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 Jan 7, 3:13 AM MST, 4 hours 17 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 313 AM MST SUN JAN 7 2007 .SHORT TERM...TODAY THROUGH TUESDAY NIGHT NORTHWEST FLOW ACROSS THE AREA THIS MORNING AS UPPER LOW MOVES ACROSS THE PLAINS. THIS FLOW WILL BRING CHANCES OF SNOW ACROSS THE WESTERN AND NORTHERN PART OF THE FORECAST AREA AS GOOD ISENTROPIC LIFT OCCURS WITH THIS PATTERN. MODELS IN GOOD AGREEMENT IN THAT THIS SYSTEM LOOKS TO BE A LITTLE WEAKER THEN THE LAST. FOR THIS REASON WILL DECREASE THE AMOUNT OF SNOWFALL OVER THE WESTERN AND NORTHERN ZONES FOR TODAY AND TONIGHT. THIS NORTHWEST FLOW AND ITS STRONG 300 MB JET WITH SPEEDS AROUND 130 KNOTS ALONG WITH A TIGHTENING PRESSURE GRADIENT WILL GO AHEAD AND ISSUE A HIGH WIND WARNING FOR THE ZONES THAT ARE IN THE WATCH. TEMPERATURES LOOK TO FALL ACROSS THE REGION THE NEXT FEW DAYS IN THIS FLOW SO WILL TREND TEMPERATURES DOWN A LITTLE BIT MORE. FLOW BECOMES MORE ZONAL THEN A WEAK RIDGE DEVELOPS BY THE END OF THE PERIOD. MOST CHANCES OF SNOW ACROSS THE AREA WILL STOP BY TUESDAY WITH ONLY SLIGHT CHANCES ACROSS OUR NORTHWESTERN ZONES. .LONG TERM...WEDNESDAY THROUGH SUNDAY THE LONG TERM WILL BE DOMINATED BY A SIGNIFICANT TROUGH USHERING IN MUCH COLDER TEMPERATURES AND THE POSSIBILITY OF SIGNIFICANT SNOWFALL ACROSS PARTS OF FORECAST AREA. WEDNESDAY WILL BE THE WARMEST DAY IN THE EXTENDED...BEFORE AN ARCTIC INTRUSION IS EXPECTED LATE WEDNESDAY/WEDNESDAY NIGHT...WITH WELL BELOW AVERAGE TEMPERATURES EXPECTED THURSDAY THROUGH SUNDAY. ON WEDNESDAY...A STRONG SHORTWAVE TROUGH SHOULD BE ACROSS SOUTHERN ALBERTA/SASKATCHEWAN...WITH ANOTHER SHORTWAVE TROUGH DIGGING SOUTH ACROSS THE PACIFIC NORTHWEST. THE NORTHERN SHORTWAVE TROUGH ACROSS SOUTHERN CANADA WILL MOVE SLOWLY EAST...WHILE THE OTHER WILL DIG INTO SOUTHERN CALIFORNIA... RESULTING/CARVING OUT A DEEP LONGWAVE TROUGH ACROSS THE WESTERN U.S. INTO CENTRAL CANADA BY THURSDAY. BOTH THE 00Z GFS AND ECMWF SHOW THIS LONGWAVE TROUGH MOVING EVER SO SLOWLY EASTWARD THROUGH SUNDAY. THE STRONG COLD FRONT ASSOCIATED WITH THIS TROUGH WILL PUSH THROUGH WEDNESDAY/WEDNESDAY NIGHT...WITH A 1050MB ARCTIC HIGH PUSHING SOUTH OUT OF SW CANADA INTO THE NORTHERN ROCKIES THURSDAY/FRIDAY. CURRENTLY...THE BEST AREA FOR SOME DECENT SNOWFALL WILL BE ACROSS THE SOUTHERN PART OF THE FORECAST AREA WEDNESDAY NIGHT THROUGH FRIDAY...WHERE THE BEST BAROCLINICITY WILL SET UP BETWEEN THE STRONG ARCTIC HIGH AND SURFACE LOW ACROSS THE FOUR CORNERS. IN ADDITION...THE NORTHERLY FLOW UP TO AROUND 700 MB BEHIND THE COLD FRONT...AND A MOIST ATMOSPHERE COULD FAVOR UPSLOPE SNOW CONDITIONS IN FAVORED AREAS DURING NORTHERLY FLOW. ALTHOUGH THE MEDIUM RANGE MODELS AGREE ON A TROUGH AND COLD AIR...THE FINE DETAILS ARE ALL OVER THE PLACE IN WHERE THE BEST JET DYNAMICS AND THE BEST BAROCLINICITY WILL SET UP. SO WILL FAVOR SOUTHERN AREAS FOR PRECIP...ESPECIALLY BEYOND WEDNESDAY NIGHT...BUT AM STILL KEEPING POPS IN THE CHANCE CATEGORY EVEN ACROSS THE SOUTH DUE TO THE UNCERTAINTY THAT STILL EXITS. WITH THE TROUGH MOVING SO SLOWLY... SOME PRECIPITATION COULD EASILY LINGER INTO THE WEEKEND...ESPECIALLY ACROSS THE SOUTHERN AND EASTERN AREAS. && .RIW WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING THIS AFTERNOON THROUGH TONIGHT FOR WYOMING ZONES 2..3 AND 19. && SHORT TERM...DH LONG TERM...WM
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 500 AM MST SUN JAN 7 2007 WYZ001>020-022>030-081200- 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 JAN 7 2007 ...HIGH WIND WARNING FOR GREEN MOUNTAINS...RATTLESNAKE RANGE... ABSAROKA MOUNTAINS AND CODY FOOTHILLS THIS AFTERNOON THROUGH TONIGHT... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT VERY STRONG WINDS THIS AFTERNOON THROUGH TONIGHT ACROSS THE ABSAROKA MOUNTAINS AND CODY FOOTHILLS...ALONG WITH THE GREEN MOUNTAINS AND RATTLESNAKE RANGE. WIND SPEEDS OF 35 TO 45 MPH WITH GUSTS TO 60 MPH ARE EXPECTED ACROSS THE LOWER ELEVATIONS WITH SPEEDS OF 45 TO 55 MPH WITH GUSTS OF UP TO 80 MPH ACROSS THE AFFECTED MOUNTAINS. THE EAST SLOPE OF THE WIND RIVER MOUNTAINS WILL ALSO SEE STRONG SOUTHWEST WINDS. SNOWFALL IS EXPECTED IN WESTERN WYOMING THIS AFTERNOON THROUGH TONIGHT ALONG WITH CONSIDERABLE BLOWING AND DRIFTING SNOW. OCCASIONAL WHITE OUT CONDITIONS...ESPECIALLY OVER SOUTH PASS WHERE WEST WINDS OF 40 TO 50 MPH WITH GUSTS TO 70 MPH ARE POSSIBLE. SNOWFALL AMOUNTS OF 2 TO 6 INCHES ARE POSSIBLE ACROSS THE WESTERN MOUNTAINS WITH 1 TO 3 INCHES IN THE WESTERN VALLEYS THIS AFTERNOON INTO TONIGHT. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY ANOTHER WINTER STORM SYSTEM WILL AFFECT WYOMING WEDNESDAY NIGHT THROUGH SATURDAY. THIS SYSTEM WILL NEED TO BE MONITORED FOR THE POSSIBILITY OF SOME HEAVY SNOWFALL...ESPECIALLY ACROSS THE SOUTHERN WYOMING WEDNESDAY NIGHT THROUGH FRIDAY. MUCH COLDER AIR IS EXPECTED BEHIND THE COLD FRONT WEDNESDAY NIGHT...WITH BELOW AVERAGE TEMPERATURES ACROSS THE ENTIRE AREA...WITH MUCH OF THE AREA EXPERIENCING THE COLDEST TEMPERATURES THIS WINTER. SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT ANY RECORDED WIND SPEEDS OVER 40 MPH AS WELL AS ANY SNOWFALL AMOUNTS. THANK YOU. TRIW
The national radar mosaic for the moment the first event began.
6 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, January 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: 4672, 4674, 4673, 4678, 4679, 4677.