A tight pressure gradient brought strong wind gusts to the high wind prone areas around Clark. A sensor along State Highway 120, eight miles south of Clark, saw many wind gusts past 58 mph with a peak of 79 mph at 2130MST on December 9.
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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 pressure gradient brought strong wind gusts to the high wind prone areas around Clark. A sensor along State Highway 120, eight miles south of Clark, saw many wind gusts past 58 mph with a peak of 79 mph at 2130MST on December 9.
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 9, 6:14 AM MST, 31 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 614 AM MST MON DEC 9 2013 .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT UPDATED TO PUT OUT A WIND CHILL WARNING FOR SOME OF THE WESTERN MOUNTAINS AND DUBOIS ZONE WHERE SUB-ZERO TEMPERATURES AND WIND ARE COMBINING TO PRODUCE WIND CHILLS OF MINUS 30 TO AS COLD AS MINUS 45. TEMPERATURES SHOULD MODERATE ENOUGH AFTER 18Z TO ALLOW THESE TO EXPIRE. AN ALBERTA CLIPPER IS RAPIDLY SWEEPING SOUTHEAST ACROSS THE CWA. THE THICKEST CLOUDS HAVE ALREADY EXITED TO EXTREME SOUTHEAST SWEETWATER COUNTY. THE LIGHT SNOWFALL IS SO FINE FROM THIS FEATURE (ALBEIT GRAINY HIGH DENSITY SNOW) THAT THERE IS QUITE THE LAG TIME FOR THIS SNOWFALL TO REACH THE GROUND. IT IS STILL SNOWING AT LND/RIW IN SPITE OF THE FACT THAT THE SKY IS MOSTLY CLEAR. TEMPS SHOULD TAKE A NOSE DIVE ONCE CLEARING BECOMES ESTABLISHED WELL BEFORE SUNRISE THIS MORNING. YET ANOTHER ALBERTA CLIPPER IS ALREADY DIVING SOUTH ACROSS BC/ALBERTA ATTM AND WILL RAPIDLY TRACK ACROSS THE AREA LATE THIS AFTERNOON/EARLY EVENING WITH MOST OF THE VORT ENERGY REMAINING OFF TO OUR NORTHEAST OVER THE NORTHERN PLAINS. THIS WILL TRANSLATE INTO LIGHT SNOWFALL OVER THE NORTHERN MTNS THIS AFTERNOON THROUGH TONIGHT. THEN ANOTHER IN A SERIES OF ALBERTA CLIPPERS WILL FOLLOW BEHIND IT AND TRACK ACROSS THE REGION ABOUT 24 HOURS LATER...WITH THE AXIS TRACKING THROUGH AROUND 00Z WEDNESDAY. THIS NEXT CLIPPER WILL BE LESS WELL DEFINED BUT BROADER RESULTING IN SLIGHTLY MORE SIGNIFICANT SNOWFALL IN THE MOUNTAINS...ESPECIALLY ON TUESDAY. SNOWFALL WILL END TUESDAY NIGHT. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH ATLAS MONDAY. THEN ON TUESDAY...TEMPS WILL WARM UP AT THE HIGHER ELEVATIONS AND IN AREAS THAT EXPERIENCE SOUTHWEST WINDS FROM RKS TO CPR. BASINS/VALLEYS WILL LIKELY REMAIN TRAPPED FOR AT LEAST A COUPLE OF MORE DAYS THROUGH WEDNESDAY. A SNOW FREE DAY IS EXPECTED IN THE MTNS AS FLATTENING HIGH PRESSURE MOVES INTO THE AREA WEDNESDAY. AS FOR THE WIND...THIS AFTERNOON AND NIGHT APPEAR TO BE THE BEST TIME FRAMES FOR STRONGER BORDERLINE HIGH WINDS. MET MOS GUIDANCE STILL INSISTS ON 30 TO 31 KNOT SUSTAINED WINDS BETWEEN 21Z THIS AFTERNOON AND 00Z THIS EVENING FOR RKS AS WELL AS 31 KNOTS FOR CASPER 15Z TUESDAY. IN ADDITION...A 16MB TO 18MB SURFACE PRESSURE GRADIENT BETWEEN GCC AND RKS...6 HEIGHT LINES SPACED EVERY 3 DECAMETERS OVER WY PROGGED BY THE NAM...AS WELL AS THE RIGHT FRONT QUAD OF THE 115 KNOT JET MAX OVERHEAD ALL BUILD A GOOD ARGUMENT FOR WIND ALONG THE SOUTHERN WIND CORRIDOR AND ALONG THE EAST SLOPE AND FOOTHILLS OF THE CONTINENTAL DIVIDE THIS AFTERNOON AND NIGHT. WILL ISSUE AN SPS RATHER THAN ISSUE A HILITE FOR NOW. .LONG TERM...THURSDAY THROUGH MONDAY MODELS REMAIN REASONABLY CONSISTENT IN THE MEDIUM RANGE PERIOD SHOWING A FLAT RIDGE ON THURSDAY FOLLOWED BY A WEAK SPLITTING TROUGH ON FRIDAY. THE WEEKEND STARTS WITH A FLAT RIDGE WHICH TURNS INTO A FAST NW FLOW WITH EMBEDDED DISTURBANCES FOR SUNDAY AND MONDAY. FLOW INCREASES LATE THURSDAY OR THURSDAY NIGHT AS THE RIDGE AXIS FLATTENS AND SHIFTS EAST OF US. INCREASED MOUNTAIN TOP FLOW AND LEE TROUGHING WILL LIKELY LEAD TO INCREASE SW FLOW IN THE WIND CORRIDOR AND CODY FOOTHILLS. A WEAK SPLITTING TROUGH IS STILL FORECAST TO MOVE THROUGH LATE FRIDAY WITH A QUICK SHOT LIGHT SNOW TO MOUNTAINS AND POSSIBLY A FEW FLURRIES ELSEWHERE. ANOTHER FLAT RIDGE ON SATURDAY BEFORE A FAST NW FLOW DEVELOPS. STRONG JET MOVES ACROSS MONTANA SATURDAY NIGHT AND SUNDAY FOR THE POSSIBILITY OF STRONG WINDS IN THE CODY FOOTHILLS AND HIGHER MOUNTAINS OF THE NORTH. TEMPERATURES MAY ALSO WARM SATURDAY NIGHT WITH SOME WIND POTENTIAL. FLOW MAY BE TIGHT ENOUGH FOR AT LEAST PARTIALLY MIX OUT THE BASINS SUNDAY AND MONDAY. PROBABLY NOT FULLY BUT WITH SOME WEAK COLD ADVECTION AT TIMES AND FAIRLY STRONG NW FLOW...WE AT LEAST HAVE A SHOT TO SEE SOME MIXING. .AVIATION.../12Z ISSUANCE/ WEST OF THE DIVIDE...KJAC-KBPI-KPNA-KRKS ROUTES. CIGS WILL GRADUALLY LOWER FROM N-S DURING THE DAY TODAY WITH AREAS OF MVFR/IFR WILL SPREAD INTO THE NORTHWEST MTNS TO VCNTY KJAC THROUGH THIS AFTERNOON. IFR/MVFR -SN IS EXPECTED TO PREVAIL FROM YELLOWSTONE NATIONAL PARK THROUGH VCNTY KJAC-KAFO BY THIS EVENING AND CONTINUE THROUGH THE OVERNIGHT. THESE CONDITIONS ARE EXPECTED TO BE MORE LOCALIZED FURTHER SOUTH FROM VCNTY KBPI-KRKS. WEST WIND WILL INCREASE ALONG THE INTERSTATE 80 CORRIDOR THIS MORNING WITH 25-35KT WINDS COMMON BY 18Z TODAY ALONG WITH AREAS OF MVFR BLSN. EAST OF THE DIVIDE...KCOD-KCPR-KLND-KRIW-KWRL ROUTES WINDS WILL INCREASE ALONG THE EAST SLOPES OF THE DIVIDE THIS MORNING WITH AREAS OF LLWS DEVELOPING VCNTY KLND-KCOD AND CONTINUING THROUGH TONIGHT. WINDS WILL MIX DOWN TO THE SURFACE VCNTY KRKS- KCPR WITH 25-35KT WINDS COMMON THIS AFTERNOON ALONG WITH AREAS OF MVFR BLSN. AN UPPER LEVEL DISTURBANCE WILL SPREAD LOCAL AREAS OF MVFR/IFR -SN PRIMARILY VCNTY AND NORTH OF INTERSTATE 90 LATE THIS AFTERNOON AND EVENING. .FIRE WEATHER... 30 TO 40 MPH WINDS WITH GUSTS TO 50 MPH ARE EXPECTED FROM ROCK SPRINGS TO CASPER AND ALONG THE EAST SLOPE AND ADJACENT FOOTHILLS OF THE DIVIDE THIS AFTERNOON AND NIGHT. TEMPERATURES WILL RECOVER TO MILDER READINGS AT THE HIGHER ELEVATIONS AND ALONG THE SOUTHERN WIND CORRIDOR FROM ROCK SPRINGS TO CASPER TUESDAY AND AT THE BASINS/VALLEYS BY THURSDAY. LIGHT SNOWFALL IS EXPECTED IN THE MOUNTAINS THROUGH TUESDAY. && .RIW WATCHES/WARNINGS/ADVISORIES... WIND CHILL WARNING UNTIL 11 AM MST THIS MORNING WYZ002-012-014>016. && UPDATE...SKRBAC SHORT TERM...LIPSON LONG TERM...SKRBAC AVIATION...AEM FIRE WEATHER...LIPSON
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 558 AM MST MON DEC 9 2013 WYZ001>020-022>030-101200- 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- 558 AM MST MON DEC 9 2013 ...WIND CHILL WARNING FOR PARTS OF THE WESTERN MOUNTAINS AND DUBOIS AREA THIS MORNING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT BITTER COLD TEMPERATURES WILL CONTINUE ACROSS THE ENTIRE AREA TODAY. SOUTHWEST WINDS OF 30 TO 40 MPH WITH SOME GUSTS TO 50 MPH CAN BE EXPECTED THIS AFTERNOON THROUGH TONIGHT FROM ROCK SPRINGS TO CASPER AS WELL AS ALONG THE EAST SLOPE OF THE CONTINENTAL DIVIDE AND THE ADJACENT FOOTHILLS. THESE WINDS WILL PRODUCE BLOWING AND DRIFTING SNOW AS WELL AS WIND CHILLS OF 10 TO 20 BELOW ZERO WITH MORNING READINGS BETWEEN 30 AND 45 BELOW ZERO IN THE TETONS...GROS VENTRES... WIND RIVERS AND ABSAROKA MOUNTAINS AND DUBOIS AREA. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT. TEAM RIVERTON
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 313 AM MST MON DEC 9 2013 WYZ015-019-020-022-028>030-092200- CASPER MOUNTAIN-EAST SWEETWATER COUNTY-FLAMING GORGE- GREEN MOUNTAINS AND RATTLESNAKE RANGE- NATRONA COUNTY LOWER ELEVATIONS-ROCK SPRINGS AND GREEN RIVER- WIND RIVER MOUNTAINS EAST- 313 AM MST MON DEC 9 2013 SOUTHWEST WINDS ARE EXPECTED TO INCREASE TO SPEEDS OF 30 TO 40 MPH ALONG WITH SOME WIND GUSTS OF 50 MPH FROM ROCK SPRINGS... ACROSS THE RED DESERT...SOUTH PASS...GREEN MOUNTAINS AND TO CASPER THIS AFTERNOON. THESE WINDS WILL CONTINUE THROUGH TONIGHT. THE WIND GUSTS WILL BE ESPECIALLY PREVALENT ALONG HIGHWAY 28 OVER SOUTH PASS AS WELL AS ALONG WYOMING BOULEVARD JUST SOUTH OF CASPER. IF TRAVELING ALONG INTERSTATE 80 THROUGH SWEETWATER COUNTY...HIGHWAY 28 OVER SOUTH PASS...HIGHWAY 287 BETWEEN BEAVER RIM AND MUDDY GAP... HIGHWAY 220 SOUTHWEST OUT OF CASPER...HIGHWAY 20/26 WEST OUT OF CASPER...INTERSTATE 25 NORTH AND EAST OUT OF CASPER OR WYOMING BOULEVARD...ANTICIPATE SUDDEN CROSS WINDS. IN ADDITION TO THE WIND... SOME BLOWING SNOW WILL LIKELY REDUCE THE VISIBILITY TO LESS THAN A QUARTER OF A MILE IN SOME AREAS. ALSO...THE COMBINATION OF WIND AND LINGERING COLD TEMPERATURES WILL RESULT IN WIND CHILL READINGS BETWEEN 10 AND 20 BELOW ZERO. WYZ002-003-092200- ABSAROKA MOUNTAINS-CODY FOOTHILLS- 313 AM MST MON DEC 9 2013 WEST WINDS ARE EXPECTED TO INCREASE TO SPEEDS OF 30 TO 40 MPH ALONG WITH SOME WIND GUSTS OF 50 MPH THIS AFTERNOON. THESE WINDS WILL CONTINUE THROUGH TONIGHT. THE WIND GUSTS WILL BE ESPECIALLY PREVALENT BETWEEN MILE MARKERS 120 AND 122 ALONG HIGHWAY 120 BETWEEN CODY AND CLARK. IF TRAVELING ALONG HIGHWAY 120 FROM THE VICINITY OF CODY TO CLARK... AS WELL AS ALONG THE CHIEF JOSEPH HIGHWAY...ANTICIPATE SUDDEN CROSS WINDS. IN ADDITION TO THE WIND...SOME BLOWING SNOW WILL LIKELY REDUCE THE VISIBILITY TO LESS THAN A QUARTER OF A MILE IN SOME AREAS. ALSO...THE COMBINATION OF WIND AND LINGERING COLD TEMPERATURES WILL RESULT IN WIND CHILL READINGS BETWEEN 10 AND 20 BELOW ZERO. LIPSON
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
The wind sensor 8 miles SSW of Clark recorded many wind gusts past 58 mph with a maximum of 79 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2013Every state in 2013This day in weather historyWarnings in Wyoming, December 2013
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: 481201.