A tight surface pressure gradient generated high wind across western Natrona County. A peak gust to 78 mph was recorded at Fales Rock RAWS around 1000MST.
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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 tight surface pressure gradient generated high wind across western Natrona County. A peak gust to 78 mph was recorded at Fales Rock RAWS around 1000MST. Shortly afterward, sustained wind of 40 mph was measured near Hiland along U.S. Highway 20/26.
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 5, 4:26 AM MST, 1 hour 44 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 426 AM MST MON JAN 5 2009 .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT WARM ADVECTIVE CLOUDS RAPIDLY HEADING SOUTHEASTWARD TOWARD BITTERLY COLD WESTERN WYOMING EARLY THIS MORNING. A LOT MORE BARK THAN BITE WITH THIS FEATURE...HOWEVER...AS CURRENT MODEL PROGS BEGINNING TO SUGGEST MOST OF THE MID- LEVEL MOISTURE WILL WRING OUT OVER THE INLAND NORTHWEST...IDAHO PANHANDLE AND NORTH-CENTRAL IDAHO IN THE NEXT SEVERAL HOURS. NO LONG WESTERLY PACIFIC FETCH AHEAD OF THIS WEAK AND SPLITTING SHORT-WAVE TROUGH TO KEEP MODERATE ISENTROPIC UPGLIDE SNOW GOING...AS WITH THE PAST TWO TROUGHS. KEPT LIKELY TO CATEGORICAL SNOW CHANCES OVER THE WEST BUT BACKED OFF ON ACCUMULATION. SNOW AMOUNTS EXPECTED TO REMAIN BELOW ADVISORY CRITERIA TODAY AND TONIGHT. WILL LET HIGH WIND WARNING IN THE ABSAROKAS AND CODY FOOTHILLS RIDE THROUGH THE NIGHT BUT CONFIDENCE WANING AS JET NOSES DUE SOUTH OVER IDAHO AND UTAH THIS MORNING. WILL UPGRADE THE HIGH WIND WATCH FOR WYZ019 AND WYZ020 WITH ALL MODELS SUGGESTING A FIVE TO EIGHT HOUR PERIOD OF 60KTS @ H7...A STRONG SFC PRESSURE GRADIENT OVER THE STATE AND A FAIR AMOUNT OF VERTICAL MIXING WILL COMBINE TO PRODUCE HIGH WIND VALUES IN THESE AREAS. THE HIGH WIND WILL RAPIDLY DECREASE THIS EVENING AS THE H7 SPEED MAX MOVES INTO THE NEBRASKA PANHANDLE. HIGH TEMPERATURES THIS AFTERNOON ARE A BIG CHALLENGE WITH WAA BEGINNING OVER THE BITTERLY COLD WESTERN VALLEYS. LOWER VALLEY AREAS IN THE FAR WEST MAY STRUGGLE TO REACH POSITIVE FAHRENHEIT VALUES AS CLOUDS AND WAA MOVE OVER. STRONG SOUTHWEST WIND WILL WARM THE CODY FOOTHILLS AND WIND LOWER ELEVATIONS OF NATRONA COUNTY INTO THE MID 30S. CENTRAL BASIN BOTTOMS WILL STRUGGLE TO GET OUT OF THE LOWER TEENS AS THE WAA ABOVE H8 STRENGTHENS TEMP INVERSIONS. STRONG NORTHWEST FLOW ALOFT ALONG WITH AREAS OF OROGRAPHIC SNOW WILL CONTINUE OVER THE CWA TONIGHT AS THE CURRENT WEAK SHORT- WAVE TROUGH MOVES SOUTHEAST INTO THE CENTRAL HIGH PLAINS. AS A VIGOROUS SHORT- WAVE TROUGH BEGINS TO MOVE INTO THE EASTERN GULF OF ALASKA ON TUESDAY...THE DOWNSTREAM UPPER LEVEL RIDGE OFF OF THE SOUTHERN CALIFORNIA COAST FOLDS OVER AND INCREASES THE PRESSURE GRADIENT OVER THE NORTHERN AND CENTRAL ROCKIES TUESDAY NIGHT INTO WEDNESDAY MORNING. THE RESULTING 145KT NORTHWESTERLY JET OVER NORTHERN WYOMING IS VERY FAVORABLE FOR SNOW IN THE NORTHERN MOUNTAINS...ESPECIALLY THE BIG HORN MOUNTAINS. THE NORTHEASTERN BIG HORN BASIN WILL ALSO HAVE TO BE MONITORED CLOSELY WITH SUCH PATTERNS IN THE PAST PRODUCING MODERATE TO STRONG BANDS OF SNOW IN THE GREYBULL AND TENSLEEP AREAS. INCREASED SNOW CHANCES IN THE BIGHORN BASIN AND BIG HORN MOUNTAINS TUESDAY NIGHT AS A RESULT OF THE FAVORABLE JET. WINTER WEATHER HIGHLIGHTS OF SOME SORT APPEAR LIKELY FOR TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING FOR THE TETON...GROS VENTRE...ABSAROKA AND BIG HORN MOUNTAINS. YELLOWSTONE PARK WILL ALSO LIKELY NEED AT LEAST A WINTER WEATHER ADVISORY LATE-DAY TUESDAY INTO WED. MORNING. RISING HEIGHTS ARE EXPECTED LATE-DAY WEDNESDAY AS AN UPPER LEVEL RIDGE BEGINS TO AMPLIFY OVER THE GREAT BASIN...AHEAD OF THE PREVIOUSLY MENTIONED GULF OF ALASKA TROUGH. ISENTROPIC UPGLIDE WITH MARGINAL MOISTURE WILL CONTINUE TO PRODUCE AREAS OF LIGHT SNOW OVER THE WEST MOUNTAINS WEDNESDAY AND WEDNESDAY NIGHT. .LONG TERM...THURSDAY THROUGH SUNDAY THE EXTENDED MODELS SHOW ZONAL FLOW THROUGH THE PERIOD WITH TIMING ISSUES WITH FAST MOVING SHORT WAVE TROUGHS. OVERALL PATTERN PUTS A GOOD CHANCE OF SNOW IN THE WESTERN MOUNTAINS WITH A GOOD CHANCE OF DOWNSLOPE WINDS EAST OF THE CONTINENTAL DIVIDE. OVERALL PATTERN SUPPORTS WARMING. TEMPERATURES MAY END UP MUCH WARMER EAST OF THE MOUNTAINS AND IN THE EAST WITH POTENTIAL HIGH WINDS. OVERALL ONLY MINOR CHANGES MADE TO PREVIOUS FORECAST WITH BLEND OF FORECAST TEMPERATURES AS NO CLEAR WINNER IS APPARENT AT THIS TIME. POTENTIAL FOR BUCKLING OF FLOW WITH CANADIAN SURGE OF COLDER AIR LATER IN THE EXTENDED WHICH WOULD PUT TEMPERATURES MUCH COLDER THAN CURRENT FORECAST AND COULD PRODUCE LIGHT UPSLOPE SNOWFALL EAST OF THE DIVIDE BUT AT THIS TIME THAT SOLUTION IS AN OUTLIER BUT CANNOT BE TOTALLY IGNORED PROVIDING SIGNIFICANTLY LOWER CONFIDENCE IN THE SATURDAY AND SUNDAY FORECAST. && .AVIATION... STRATUS CLOUD DECKS WILL GRADUALLY LOWER ALONG AND WEST OF THE DIVIDE TODAY WITH AREAS OF MVFR AND LOCAL IFR CIGS/VSBYS IN -SN DEVELOPING BY 18Z ALONG WITH MOUNTAIN OBSCURATIONS. EAST OF THE DIVIDE...SOUTHWEST WIND WILL INTENSIFY BTWN RKS-CPR WITH MAX SFC WND 30-40KT G60KT EXPECTED 15Z-22Z. AREAS OF LLWS WILL BE ENCOUNTERED ALONG THE EAST SLOPES OF MOUNTAIN RANGES WITH WEST WIND 30-40KT 1-2KFT AGL ABOVE VALLEY INVERSIONS PRIMARILY FROM KCOD-KLND AND ALONG THE EAST SLOPES OF THE BIG HORN MOUNTAINS. && .FIRE WEATHER... AREAS OF LIGHT SNOW ALONG WITH BITTERLY COLD TEMPERATURES ARE EXPECTED OVER THE WEST TODAY. SOUTHWEST WIND WILL BE ON THE INCREASE...ESPECIALLY IN THE CODY FOOTHILLS AND THROUGH THE WIND CORRIDOR FROM JUST NORTHEAST OF ROCK SPRINGS TO CASPER. POOR SMOKE DISPERSAL IS ANTICIPATED TODAY THROUGH TUESDAY AS WARMING NEAR MOUNTAIN TOP LEVEL CAPS THE ATMOSPHERE. SIGNIFICANT SNOWFALL IS EXPECTED FOR THE NORTHERN MOUNTAINS TUESDAY NIGHT AND WEDNESDAY MORNING. && .RIW WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING UNTIL 5 PM MST MONDAY FOR WYZ002. HIGH WIND WARNING FROM 5 AM TO 5 PM MST MONDAY FOR WYZ019-020. HIGH WIND WARNING UNTIL 11 AM MST MONDAY FOR WYZ003. && SHORT TERM...CHURCH LONG TERM...C.BAKER AVIATION...AEM FIRE WEATHER...CHURCH
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 501 AM MST MON JAN 5 2009 WYZ001>020-022>030-061201- 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- 501 AM MST MON JAN 5 2009 ...HIGH WIND WARNING FOR THE CODY FOOTHILLS THIS MORNING... ...HIGH WIND WARNING FOR THE ABSAROKA MOUNTAINS TODAY... ...HIGH WIND WARNING FOR THE GREEN/RATTLESNAKE MOUNTAINS AND THE LOWER ELEVATIONS OF NATRONA COUNTY TODAY... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT HIGH WIND SPEEDS ARE EXPECTED IN THE CODY FOOTHILLS THIS MORNING. THE HIGH WIND IN THE CODY FOOTHILLS IS EXPECTED TO SUBSIDE AROUND MIDDAY. HIGH WIND IS ALSO EXPECTED IN THE ABSAROKA MOUNTAINS...THE GREEN/RATTLESNAKE MOUNTAINS AND THE LOWER ELEVATIONS OF NATRONA COUNTY TODAY. PLEASE SEE CYSNPWRIW FOR DETAILS. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY A STRONG AND MOIST NORTHWEST FLOW ALOFT WILL BRING A GOOD CHANCE OF WIDESPREAD ACCUMULATING SNOW TO THE NORTHERN MOUNTAINS TUESDAY NIGHT AND WEDNESDAY. STRONG WINDS WILL BE POSSIBLE EAST OF THE CONTINENTAL DIVIDE. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ASKED TO REPORT HIGH WIND AND SNOW ACCUMULATION. THANK YOU. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
2 high wind. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2009Every state in 2009This day in weather historyWarnings in Wyoming, January 2009
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: 142203, 142204.