A strong pressure gradient produced widespread wind gusts of 55 to 74 mph across areas east of the Continental Divide. An approaching cold front increased southwest flow across western Wyoming late Monday, December 29 producing high wind in Teton County into the early morning hours Tuesday.
Every event with a place to put it; 7 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.
A strong pressure gradient produced widespread wind gusts of 55 to 74 mph across areas east of the Continental Divide. An approaching cold front increased southwest flow across western Wyoming late Monday, December 29 producing high wind in Teton County into the early morning hours Tuesday. Notable peak wind gusts across the lower elevations were 76 mph at Hunt Field in Lander, 74 mph on U.S. Highway 287 over Beaver Rim, 67 mph at Jackson Hole Airport, 63 mph on Interstate 90 north of Buffalo, and 59 mph at both the Buffalo and Riverton ASOS. Peak gusts around 95 mph were measured in the Absaroka Range and at the summit of Jackson Hole Mountain Resort.
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 29, 9:41 AM MST, 6 hours 4 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 941 AM MST MON DEC 29 2008 SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT UPDATED TO REMOVE THE WINTER WEATHER ADVISORIES FOR THE JACKSON AND STAR VALLEYS FOR TODAY ALONG WITH THE WIND RIVER MOUNTAINS. THE WINTER WX ADVISORIES HAVE ALSO BEEN EXTENDED FOR THE FAR WEST MTNS THROUGH 11 PM THIS EVENING. NAM AND GFS IN GOOD AGREEMENT ON MAIN SYNOPTIC FEATURES AFFECTING WESTERN AND CENTRAL WYOMING TODAY THROUGH WEDNESDAY NIGHT. STRONG SHORTWAVE WILL MOVE FROM THE EASTERN PAC INTO THE INTERIOR NORTHWEST TODAY. UPPER LEVEL FLOW AHEAD OF THIS SHORTWAVE WILL BACK FROM THE WEST TO THE SOUTHWEST ACROSS WESTERN WY TODAY. NAM AND GFS INDICATE THAT BEST ISENTROPIC LIFT ALONG THE 295 K SURFACE WILL SHIFT NORTHWARD TODAY...AS FLOW SHIFTS TO THE SOUTHWEST. SNOWFALL ACROSS THE SALT RIVER AND WYOMING RANGES...THE WIND RIVER MOUNTAINS AND THE STAR VALLEY WILL GRADUALLY LIGHTEN UP DURING THE AFTERNOON HOURS. SNOWFALL ACROSS TETON COUNTY AND YELLOWSTONE NATIONAL PARK WILL CONTINUE THROUGH LATE THIS AFTERNOON WITH PERIODS OF LIGHT TO OCCASIONALLY MODERATE SNOW. WILL KEEP THE WINTER WEATHER ADVISORIES FOR THIS AREA IN EFFECT THROUGH 00Z TUESDAY WITH 1 TO 2 INCHES OF ADDITIONAL SNOWFALL ACROSS THE SOUTHERN ADVISORY AREAS AND 2 TO 5 INCHES POSSIBLE ACROSS TETON COUNTY AND YELLOWSTONE NATIONAL PARK THROUGH LATE THIS AFTERNOON. SOUTHWEST WINDS IN THE HIGHER PEAKS OF THE ADVISORY AREAS WILL GUST UP TO 50 MPH THROUGH THIS AFTERNOON AHEAD OF AN APPROACHING COLD FRONTAL BOUNDARY. A LEE SURFACE TROUGH OF LOW PRESSURE IS PROJECTED TO DEVELOP TODAY FROM EASTERN MT SOUTHWARD ACROSS EASTERN WY. THE INCREASING SURFACE GRADIENT COMBINED WITH INCREASING H7 WINDS...SPEEDS PER NAM AND GFS OF 50 TO 65 KT TODAY...WILL CREATE A HIGHLY MIXED BOUNDARY LAYER ACROSS EASTERN SWEETWATER AND THE LOWER ELEVATIONS OF NATRONA COUNTY WITH STRONGER WINDS ALOFT MIXING INTO THE LOWER LAYERS OF THE ATMOSPHERE. HAVE ISSUED A HIGH WIND WARNING FOR THESE AREAS FROM 15Z TODAY THROUGH 06Z TUESDAY FOR WIND GUSTS OF 60 TO 70 MPH. SURFACE LOW PRESSURE WILL CLOSE OFF OVER EASTERN MT AND THE WESTERN DAKOTAS THIS EVENING THROUGH 06Z TUESDAY. STRONG PRESSURE GRADIENT IS EXPECTED TO KEEP THE THREAT OF HIGH WINDS IN EASTERN SWEETWATER COUNTY AND THE LOWER ELEVATIONS OF NATRONA COUNTY THROUGH 06Z TUESDAY. SHORTWAVE WILL MOVE ACROSS SOUTHERN MT TONIGHT TO A POSITION OVER SOUTHEASTERN MT BY 12Z TUESDAY. SURFACE COLD FRONT AHEAD OF THE SHORTWAVE TROUGH WILL MOVE ACROSS NORTHERN WY TONIGHT AND INTO SOUTHERN WY AROUND DAWN TUESDAY. ADEQUATE PAC MOISTURE AND UPSLOPE FLOW ACROSS THE NORTHWESTERN MOUNTAINS TONIGHT WILL COMBINE WITH DYNAMICS FROM THE SHORTWAVE TO BRING LIGHT SNOW TO THE REGION TONIGHT WITH AT LEAST 2 TO 3 INCHES OF ACCUMULATION. SIGNIFICANT RIDGING ALOFT TUESDAY AND BUILDING HIGH PRESSURE AT THE SFC WILL PRODUCE DRY WEATHER...WHILE CAA AND AFTERNOON H7 TEMPERATURES IN THE MINUS 8 C TO MINUS 16 C RANGE WILL RESULT IN A 15 TO 20 F DROP IN HIGH TEMPERATURES COMPARED TO HIGH TEMPERATURES TODAY. HIGHS TUESDAY WILL BE SLIGHTLY BELOW NORMAL IN THE 20S IN THE LOWER ELEVATIONS AND IN THE TEENS IN THE HIGHER ELEVATIONS. A MORE WESTERLY FLOW ALOFT WEDNESDAY WILL BRING SLIGHTLY WARMER AIR INTO WESTERN AND CENTRAL WY AHEAD OF ANOTHER SHORTWAVE MOVING THROUGH THE PAC NW. THIS SHORTWAVE WILL MOVE ACROSS NORTHERN WY WEDNESDAY NIGHT BRINGING A BETTER FETCH OF PAC MOISTURE AND A REINFORCEMENT OF COLD AIR WITH THE COLD FRONT REACHING SOUTHERN WY BY EARLY THURSDAY MORNING. BEST PROSPECT FOR LIGHT TO MODERATE SNOW ACCUMULATIONS WILL BE WEST OF THE DIVIDE WEDNESDAY NIGHT WITH SOME LIGHT ACCUMULATIONS POSSIBLE EAST OF THE DIVIDE AND IN THE BIGHORN MOUNTAINS. LONG TERM...THURSDAY THROUGH MONDAY GFS/ECMWF/GEFS MEAN IN GOOD AGREEMENT TO START THIS PERIOD WITH OMEGA BLOCK OVER THE ALEUTIAN CHAIN BEING UNDERCUT WHILE LARGE- SCALE PATTERN OVER CANADA/NORTHERN ATLANTIC RETROGRESSES WITH GYRE OVER CANADA BECOMES MORE CONSOLIDATED OVER THE NORTHWEST TERRITORIES AND YUKON. STRONG NORTHWEST FLOW TO FOLLOW WEDNESDAY NIGHTS SHORTWAVE PASSAGE WITH N-S ORIENTED JET STREAK SHIFTING EAST INTO THE NORTHERN HIGH PLAINS PUTTING WYOMING ON THE ANTICYCLONIC RIGHT EXIT REGION. THIS FLOW WILL FAVOR WINDY TO VERY WINDY CONDITIONS THROUGH THE NW WIND CORRIDORS...PRIMARILY THE EASTERN BIG HORN BASIN EAST THROUGH JOHNSON COUNTY AND SOUTH THROUGH RIVERTON ALONG WITH THE INTERSTATE 80 CORRIDOR. FLOW QUICKLY BACKS THURSDAY NIGHT AHEAD OF NEXT SHORTWAVE WITH WARM ADVECTION PRECIPITATION SPREADING BACK INTO THE WEST AND INTENSIFYING THROUGH FRIDAY. LEE TROUGH TO STRENGTHEN ACROSS EASTERN WYOMING FRIDAY WITH STRONG SW WIND POSSIBLE BETWEEN ROCK SPRINGS AND CASPER ALONG WITH WARMER TEMPERATURES ACROSS THE REGION. NEXT SHORTWAVE SCHEDULED TO MOVE THROUGH FRIDAY NIGHT CONSISTENT WITH THE TIMING IN THE SHORTTERM OF SHORTWAVE PASSAGES ABOUT EVERY 48 HOURS IN THIS PROGRESSIVE PATTERN. ASSOCIATED COLD FRONT WILL BRING COOLER CONDITIONS ACROSS THE AREA SATURDAY ALONG WITH CHANCES OF PRECIPITATION ACROSS NORTH CENTRAL. UPSTREAM...RIDGE BUILDS NEAR 150W RESULTING IN DOWNSTREAM TROUGH TAKING SHAPE OVER WESTERN U.S. OVER THE WEEKEND. BOTH GFS AND ECMWF ADVERTISING A SPLIT FLOW WITH MAIN PIECE OF ENERGY DIGGING INTO THE SOUTHWEST U.S. SATURDAY AND SATURDAY NIGHT...AND THEN GETTING KICKED OUT AS NEXT STRONG PACIFIC JET STREAK PLOWS INTO NORTHWEST U.S. MONDAY. BULK OF PRECIPITATION EXPECTED TO STAY SOUTH OF THE AREA OVER THE FOUR CORNERS REGION WITH THIS SW LOW. THE ONSET OF ANOTHER ROUND OF SIGNIFICANT SNOWFALL IN THE WEST AND STRONG WIND IN THE ABSAROKA MOUNTAINS AND CODY FOOTHILLS A GOOD BET FOR MONDAY. AVIATION... SHORTWAVE RIDGE SHUNTED SOME OF THE PACIFIC MOISTURE TO OUR NORTH DURING THE OVERNIGHT HOURS. UPPER LEVEL FLOW WILL BACK TO THE WEST-SOUTHWEST AS THIS RIDGE AXIS MOVES THROUGH THE STATE THIS MORNING. INCREASING WEST-SOUTHWEST FLOW WILL LEAD TO A VERY WINDY DAY AT KCPR. SURFACE PRESSURE GRADIENT SUFFICIENT TO PRODUCE GUSTS OF 40-45KTS. HOWEVER...LOOKS LIKE LOWER ATMOSPHERE WILL MIX SUFFICIENTLY TO ALLOW FOR 50-55KT WINDS IN THE 700/750MB LAYER TO SURFACE DURING THE AFTERNOON. THESE WINDS WILL CONTINUE TO CREATE MODERATE TO SEVERE TURBULENCE IN THE LEE OF THE MOUNTAINS... ESPECIALLY THE WIND RIVER AND BIGHORN RANGES. TO THE WEST...WESTERLY FLOW WILL ALLOW LIGHT SNOW TO FALL THROUGH MONDAY EVENING. MOUNTAIN OBSCURATIONS WILL PERSIST THROUGH 06Z/TUE. BEST CHANCE FOR IFR CONDITIONS AT KJAC APPEARS TO BE MONDAY MORNING WITH CONDITIONS IMPROVING TO MVFR AFTER 18Z/MON. NEXT UPPER LEVEL SYSTEM WILL TRACK INTO NORTHWEST WYOMING AROUND 00Z/TUE. EXPECT SOME INCREASED SNOW IN NORTHWEST WYOMING...BUT ISENTROPIC LIFT AND MOISTURE DECREASES RAPIDLY BETWEEN 00Z AND 06Z/TUE OVER THIS AREA. HAVE BEGUN TRENDING TOWARD IMPROVING CONDITIONS DURING THIS TIME. WINDS AT KBPI...KPNA AND KRIW SHOULD VEER TO THE WEST-NORTHWEST AND INCREASE AROUND 06Z/TUE AS THIS SYSTEM PASSES TO OUR NORTH. FIRE WEATHER... LIGHT SNOW WILL GRADUALLY DIMINISH IN THE WEST TODAY...ALTHOUGH LIGHT TO MODERATE SNOW IS EXPECTED TO CONTINUE THROUGH LATE AFTERNOON IN THE NORTHWEST MOUNTAINS. STRONG WINDS WITH GUSTS EXCEEDING 60 MPH ARE EXPECTED FROM MID MORNING THROUGH LATE THIS EVENING IN THE WIND CORRIDOR FROM EASTERN SWEETWATER COUNTY TO NATRONA COUNTY. STRONG WIND GUSTS ARE ALDO EXPECTED IN THE HIGHER TERRAIN TODAY ACROSS WESTERN AND CENTRAL WYOMING WITH GUSTS UP TO 60 MPH. HIGH TEMPERATURES TODAY WILL WARM UP SIGNIFICANTLY EAST OF THE DIVIDE WITH LOWER ELEVATION TEMPERATURES GENERALLY IN THE 40S. A COLD FRONT WILL BRING COLDER AND DRIER AIR TO WYOMING LATE TONIGHT THROUGH TUESDAY. UPSLOPE SNOW BEHIND THE FRONT TONIGHT COULD BRING 2 TO 3 INCHES TO THE NORTHWEST MOUNTAINS WITH LOCALIZED AMOUNTS OF 4 TO 5 INCHES BY TUESDAY MORNING. HIGH PRESSURE WILL MOVE ACROSS WYOMING TUESDAY WITH HIGH TEMPERATURES SLIGHTLY BELOW NORMAL. && .RIW WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ019-020- 030. WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR WYZ001- 012-024. && UPDATE...SKRBAC SHORT TERM...SMITH LONG TERM...AEM AVIATION...AEM FIRE WEATHER...SMITH
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 335 PM MST MON DEC 29 2008 WYZ001>020-022>030-301200- 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- 335 PM MST MON DEC 29 2008 ...HIGH WIND WARNING FOR EASTERN SWEETWATER COUNTY AND NATRONA COUNTY THIS MORNING THROUGH MIDNIGHT... ...HIGH WIND WARNING FOR THE EAST SLOPE OF THE WIND RIVER MOUNTAINS TONIGHT... ...HIGH WIND WATCH FOR THE LANDER FOOTHILLS THIS EVENING... ...WINTER WEATHER ADVISORIES FOR THE MOUNTAINS OF FAR WESTERN WYOMING THROUGH THIS EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT SUSTAINED SOUTHWEST WIND FROM 30 TO 45 MPH WITH GUSTS EXCEEDING 60 MPH ARE EXPECTED IN EASTERN SWEETWATER COUNTY...SOUTHEASTERN FREMONT AND THE LOWER ELEVATIONS OF NATRONA COUNTY THROUGH LATE THIS EVENING. THE STRONGEST WIND WILL OCCUR LATER THIS AFTERNOON THROUGH THE EVENING HOURS. ANOTHER AREA OF HIGH WINDS ARE EXPECTED TO DEVELOP ALONG THE EAST SLOPE OF THE WIND RIVER MOUNTAINS THIS EVENING AND CONTINUE OVERNIGHT. SOUTHWEST WINDS OF 40 TO 55 MPH WITH GUSTS OF 70 TO 80 MPH ARE EXPECTED OVERNIGHT. THESE HIGH WINDS WILL ALSO IMPACT SOUTH PASS AT TIMES. THE COMBINATION OF STRONG WINDS AND CONSIDERABLE BLOWING AND DRIFTING SNOW WILL MAKE FOR DANGEROUS TRAVEL OVER SOUTH PASS AT TIMES TONIGHT. HIGH WINDS MAY ALSO DEVELOP IN THE LANDER FOOTHILLS TONIGHT INCLUDING THE TOWN OF LANDER. THE HIGH WINDS THAT ARE EXPECTED TO OCCUR ALONG THE EAST SLOPE OF THE WIND RIVER MOUNTAINS MAY MIX DOWN AT TIMES IN THE LANDER AREA AND VICINITY. BE ALERT FOR THESE POTENTIAL HIGH WINDS THROUGH THE EVENING. A MOIST FLOW OF PACIFIC AIR WILL BRING LIGHT TO OCCASIONALLY MODERATE SNOW TO THE FAR WESTERN MOUNTAINS THROUGH THIS EVENING. THE BEST SNOWFALL RATES WILL BE LATER THIS AFTERNOON THROUGH THIS EVENING. THE TETON AND GROS VENTRE RANGES AND HIGHER ELEVATIONS IN SOUTHWEST YELLOWSTONE PARK WILL RECEIVE 6 TO 14 INCHES OF SNOW...WHILE THE LOWER ELEVATIONS OF YELLOWSTONE PARK WILL RECEIVE 3 TO 7 INCHES OF NEW SNOW. SEE HIGH WIND WARNING AND WINTER WEATHER ADVISORY PRODUCTS FOR MORE INFORMATION. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SATURDAY THE NEXT PACIFIC STORM SYSTEM WILL BRING THE POTENTIAL FOR SIGNIFICANT SNOWFALL TO THE WESTERN MOUNTAINS AND FAR WEST VALLEYS WEDNESDAY AND WEDNESDAY NIGHT. THIS NEXT SYSTEM ALSO MAY BRING STRONG DOWNSLOPE WINDS ALONG THE EAST SLOPES OF THE ABSAROKA MOUNTAINS AND CODY FOOTHILLS WEDNESDAY MORNING...AS WELL AS STRONG SOUTHWEST WINDS ACROSS THE WIND CORRIDOR BETWEEN ROCK SPRINGS AND CASPER BY WEDNESDAY AFTERNOON. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT ANY HIGH WINDS IN FREMONT...EASTERN SWEETWATER COUNTY AND IN THE LOWER ELEVATIONS OF NATRONA COUNTY THROUGH LATE THIS EVENING. SPOTTERS ARE ENCOURAGED TO REPORT SNOWFALL AMOUNTS IN WESTERN WYOMING THIS EVENING. THANK YOU. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
7 high wind. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2008Every state in 2008This day in weather historyWarnings in Wyoming, December 2008
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: 142163, 142162, 142164, 142168, 142165, 142166, 142167.