A tightening pressure gradient ahead of an approaching cold front produced high wind across much of Natrona County. A peak gust of 68 mph was recorded in Casper.
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The episode as NWS RIW wrote it up.
A tightening pressure gradient ahead of an approaching cold front produced high wind across much of Natrona County. A peak gust of 68 mph was recorded in Casper. An automated station in western Natrona County measured gusts of 71 and 73 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 24, 3:16 AM MST, 7 hours 44 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 316 AM MST MON DEC 24 2007 .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT LARGE UPPER LEVEL SHORT-WAVE TROUGH MAKING ITS WAY ASHORE EARLY THIS MORNING. THE LATEST GFS AND ECMWF IN GOOD AGREEMENT MOVING THIS TROUGH THROUGH CENTRAL IDAHO TODAY AND THEN THROUGH CENTRAL WYOMING EARLY TUESDAY MORNING. PUSHED BACK THE TIMING FOR THE WINTER STORM WARNING TO 12Z TODAY WITH MOST OF THE RADAR ECHOS STILL IN EASTERN IDAHO. DECIDED ON SNOW ADVISORY FOR THE BIG HORN MOUNTAINS AND JOHNSON COUNTY WITH ALL MODELS SHOWING STRONG FRONTOGENESIS TAKING PLACE OVER SOUTHEAST MONTANA EARLY THIS AFTERNOON...SAGGING THE FRONT AND ASSOCIATED STRONG PRECIPITATION BAND SOUTHWARD LATE THIS AFTERNOON. STRONG NORTHWEST WIND IN THE BUFFALO AREA WILL PRODUCE WIDESPREAD BLOWING AND DRIFTING SNOW MAKING TRAVEL VERY DIFFICULT ALONG I-25/I-90 LATE THIS AFTERNOON THROUGH EARLY EVENING. LOCAL SNOWFALL AMOUNTS NEAR A FOOT ARE POSSIBLE ALONG NORTH FACING SLOPES IN THE BIG HORN MOUNTAINS AS VERY STRONG SURFACE AND NEAR SURFACE CONVERGENCE COMBINES WITH UPSLOPE FLOW AND GOOD LAPSE RATES. ALSO ISSUED A SNOW ADVISORY FOR THE WESTERN WIND RIVER MOUNTAINS...UPPER GREEN RIVER BASIN FOOTHILLS AND SOUTHERN LINCOLN COUNTY AS GOOD FRONTOGENETIC FORCING EXPECTED TO PRODUCE A STRONG FRONTAL BAND OF SNOW DURING THE AFTERNOON. DURATION THE MAIN ISSUE WITH THESE AREAS BUT WITH GOOD INSTABILITY PROGGED OVER THESE AREAS DURING THE AFTERNOON...EXPECTING VERY GOOD SNOWFALL RATES FOR AT LEAST 2-4 HOURS. STRONG SURFACE FRONT STILL ON TRACK TO PLOW THROUGH THE BIG HORN BASIN EARLY THIS EVENING AND THEN SOUTHWARD THROUGH THE OWL CREEK MOUNTAINS INTO THE WIND RIVER BASIN AND CODY FOOTHILLS AROUND 02Z. SNOW IS EXPECTED ALONG AND BEHIND THE FRONT FOR SEVERAL HOURS BEFORE WEST-NORTHWEST FLOW DEVELOPS AROUND MIDNIGHT. EXPECTING 1 TO 2 INCH AMOUNTS IN THE CODY FOOTHILLS...BIG HORN AND WIND RIVER BASINS...WITH 2 TO 4 INCHES IN THE LANDER FOOTHILLS. SNOWFALL IN THE CASPER AREA AND MOST OF NATRONA COUNTY EXPECTED TO RAPIDLY MOVE IN AROUND 03Z WITH 2 TO 4 INCHES LIKELY IN AND AROUND CASPER WITH UP TO 8 INCHES POSSIBLE FOR CASPER MOUNTAIN. WILL LET THE DAY SHIFT TAKE ONE MORE LOOK AT DATA WITH THIS TROUGH COMPLETELY ONSHORE BEFORE DECING ON POTENTIAL WINTER HIGHLIGHTS FOR NATRONA COUNTY TONIGHT. A TRAILING VERY WEAK SHORT-WAVE TROUGH MOVES THROUGH THE AREA CHRISTMAS DAY BRINGING WITH IT SOME CLOUDS AND A FEW MOUNTAIN FLURRIES OR LIGHT SNOW SHOWERS. NEXT PACIFIC TROUGH STILL EXPECTED TO BEGIN TO IMPACT THE AREA WEDNESDAY MORNING. LATEST GLOBAL MODELS INDICATING THIS TROUGH WILL DIG FARTHER SOUTH THROUGH THE GREAT BASIN...PUTTING WESTERN AND CENTRAL WYOMING UNDER A -37 DEG C COLD POOL AT H5. THIS COLD POOL EXPECTED TO PRODUCE NUMEROUS MOUNTAIN SNOW SHOWERS WITH SCATTERED SNOW SHOWERS IN THE BASINS AND VALLEYS WEDNESDAY THROUGH WEDNESDAY NIGHT. .LONG TERM...THURSDAY THROUGH MONDAY THE PARADE OF SYSTEMS PUSHING SOUTHEAST OUT OF THE THE GULF OF ALASKA INTO WEST WILL CONTINUE THROUGH THE WEEKEND...BUT BOTH THE 00Z ECMWF AND GFS SHOW THE POSSIBILITY OF A HIGH AMPLITUDE RIDGE DEVELOPING IN THE EASTERN PACIFIC/WEST COAST BY EARLY NEXT WEEK. A SPLITTING TROUGH IS EXPECTED TO BE EXITING THE AREA ON THURSDAY...BUT SHOULD STILL WARRANT POPS...ESPECIALLY EAST OF THE DIVIDE. THEN...A MORE WESTERLY FLOW DEVELOPS WITH LOW AMPLITUDE SYSTEMS MOVING THROUGH THE WESTERLIES. THIS WILL RESULT IN A DECENT CHANCE OF A PROLONGED ISENTROPIC UPGLIDE/OROGRAPHIC LIFT ACROSS THE WEST...ENHANCED BY A FEW SHORTWAVES. THE BEST SHORTWAVE SEEMS TO AFFECT THE FORECAST AREA FRIDAY NIGHT INTO SATURDAY. BY EARLY NEXT WEEK...NORTHWEST FLOW COULD DEVELOP WITH RIDGE TO THE WEST. A FEW DISTURBANCES IN THIS FLOW COULD KEEP AN ACTIVE PATTERN GOING. EXCEPT FOR THURSDAY...WILL HAVE LITTLE POPS EAST OF THE DIVIDE...BUT THIS MIGHT CHANGE WITH THE SYSTEM ON SATURDAY...AND ONCE AND IF NORTHWEST FLOW DEVELOPS EARLY NEXT WEEK. THESE SYSTEMS AND ASSOCIATED COLD FRONTS WILL RESULT IN BELOW AVERAGE TEMPERATURES...WITH TEMPS CREEPING TOWARD SEASONAL TEMPS BY THE END OF THE PERIOD...ESPECIALLY WHERE GOOD MIXING WILL OCCUR. BASINS...WITH STEEP INVERSIONS WILL PROBABLY REMAIN LOCKED INTO THE DEEP FREEZE. && .AVIATION... A STORM SYSTEM WILL MOVE ACROSS THE PACIFIC NORTHWEST AND THE NORTHERN ROCKIES TOADY AND TONIGHT. THIS STORM WILL PRODUCE UPSLOPE SNOW ACROSS FAR WESTERN WYOMING AND WILL CREATE MVFR TO IFR CONDITIONS IN SNOW AT KJAC...KPNA AND KBPI IN THE MORNING THROUGH MONDAY EVENING. AHEAD OF THIS STORM THE SURFACE PRESSURE GRADIENT WILL BE STRONG FROM SOUTHERN WYOMING TO EASTERN WYOMING...AND SOUTHWEST TO WEST WINDS AT KRKS AND KCPR WILL RANGE FROM 10 TO 20 KT WITH GUSTS AROUND 30 KT FROM THROUGH THE EVENING. A COLD FRONT IN THE AFTERNOON HAS THE POTENTIAL TO BRING MVFR CONDITIONS IN LIGHT SNOW TO THE REMAINDER OF TAF SITES MOVING INTO KRIW...KLND AND KCPR WHERE SNOW ASSOCIATED WITH THE COLD FRONT IS NOT EXPECTED UNTIL AFTER 00Z. MUCH OF THE AREA WILL SEE MVFR TO IFR CONDITIONS WITH MOUNTAINS AND HIGHER TERRAIN OBSCURED. && .FIRE WEATHER... SIGNIFICANT SNOWFALL IS EXPECTED OVER WESTERN AND NORTHEAST WYOMING TODAY THROUGH TONIGHT. STRONG SOUTHWEST WINDS WILL ACCOMPANY THIS SYSTEM AS LOW PRESSURE DEVELOPS OVER EASTERN WYOMING MONDAY AFTERNOON. A STRONG COLD FRONT WILL USHER IN STRONG NORTH WINDS AND SNOW TO AREAS EAST OF THE DIVIDE THIS AFTERNOON. VERY STRONG NORTHWEST TO NORTH WINDS IN AND NEAR BUFFALO ARE EXPECTED THIS EVENING. ANOTHER PACIFIC STORM IS EXPECTED TO BRING SCATTERED SNOW SHOWERS TO THE DISTRICT ON WEDNESDAY. && .RIW WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING FROM 5 AM EARLY THIS MORNING TO 8 PM MST THIS EVENING FOR WYZ012-013-023-024. SNOW ADVISORY FROM 8 AM THIS MORNING TO 8 PM MST THIS EVENING FOR WYZ014-025-027. SNOW ADVISORY FROM 2 PM THIS AFTERNOON TO 1 AM MST TUESDAY FOR WYZ008>011. SNOW ADVISORY FROM 5 AM EARLY THIS MORNING TO 8 PM MST THIS EVENING FOR WYZ001. && SHORT TERM...CHURCH LONG TERM...WM AVIATION...C.BAKER FIRE WEATHER...CHURCH
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 500 AM MST MON DEC 24 2007 WYZ001>020-022>030-251200- 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 MON DEC 24 2007 ...WINTER STORM WARNING IN EFFECT FOR JACKSON HOLE STAR VALLEY TETON GROS VENTRE SALT AND WYOMING RANGES THROUGH 8 PM THIS EVENING... ...SNOW ADVISORY IN EFFECT THROUGH 8 PM MST THIS EVENING FOR YELLOWSTONE NATIONAL PARK... ...SNOW ADVISORY FROM 8 AM THIS MORNING TO 8 PM MST THIS EVENING FOR WESTERN WIND RIVER MOUNTAINS UPPER GREEN RIVER BASIN FOOTHILLS AND SOUTHERN LINCOLN COUNTY... ...SNOW ADVISORY FROM 2 PM THIS AFTERNOON TO 1 AM MST TUESDAY FOR BIG HORN MOUNTAINS AND JOHNSON COUNTY... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT SNOW WILL CONTINUE TO DEVELOP ACROSS WESTERN WYOMING THIS MORNING. SNOW WILL BE LIGHT TO MODERATE DURING THE MORNING AND WILL BECOME MODERATE TO HEAVY AROUND MIDDAY OVER THE WEST. EAST OF THE DIVIDE... SNOW WILL DEVELOP AROUND MIDDAY...MAINLY ACROSS THE NORTH...AND BECOME MODERATE TO HEAVY THIS AFTERNOON...AND SHIFT SOUTH AS A STRONG COLD FRONT SHIFTS PUSHES SOUTH...EAST OF THE DIVIDE. TOTAL SNOW ACCUMULATIONS OF 4 TO 9 INCHES ARE ANTICIPATED IN THE JACKSON HOLE AND THE STAR VALLEY...WITH 8 TO 14 INCHES EXPECTED IN THE TETONS...GROS VENTRE MOUNTAINS...SALT RANGE AND THE WYOMING RANGE. SNOWFALL ACCUMULATIONS THROUGH THIS EVENING IN YELLOWSTONE PARK WILL RANGE FROM 5 TO 10 INCHES IN SOUTHERN PORTIONS OF THE PARK TO 3 TO 6 INCHES IN THE NORTHERN SECTIONS. SNOW ACCUMULATIONS IN THE WESTERN WIND RIVER MOUNTAINS...THE UPPER GREEN RIVER BASIN FOOTHILLS...AND SOUTHERN LINCOLN COUNTY WILL RANGE FROM 2 TO 5 INCHES IN THE LOWER ELEVATIONS WITH 4 TO 9 EXPECTED IN THE MOUNTAINS. SNOWFALL TOTALS IN THE BIG HORN MOUNTAINS WILL RANGE FROM 6 TO 10 INCHES WITH 2 TO 5 INCHES EXPECTED IN JOHNSON COUNTY. WIDESPREAD BLOWING AND DRIFTING IS EXPECTED IN JOHNSON COUNTY LATE THIS AFTERNOON THROUGH THE EVENING. ONE TO TWO INCHES OF SNOW IS EXPECTED ACROSS THE WIND RIVER BASIN TONIGHT...WITH 2 TO 4 INCHES EXPECTED ACROSS NATRONA COUNTY...INCLUDING CASPER...WITH 4 TO 6 INCHES ACROSS CASPER MOUNTAIN. .DAYS TWO THROUGH SEVEN...CHRISTMAS DAY THROUGH SUNDAY ANOTHER PACIFIC STORM SYSTEM IS EXPECTED TO AFFECT THE COWBOY STATE WEDNESDAY INTO THURSDAY. PLEASE STAY TUNED THIS HOLIDAY SEASON FOR THE LATEST FORECASTS AS A SERIES OF STORM SYSTEMS WILL CONTINUE TO IMPACT WESTERN AND CENTRAL WYOMING. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT ANY SNOWFALL AMOUNTS TO THE NATIONAL WEATHER SERVICE. 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 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: 65563, 65564.