An approaching cold front generated a tightening pressure gradient and produced yet another high wind episode around Clark. Wind gusts to the west and south of Clark frequently topped 60 mph with a peak of 76 mph on December 18 at 0230MST.
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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.
An approaching cold front generated a tightening pressure gradient and produced yet another high wind episode around Clark. Wind gusts to the west and south of Clark frequently topped 60 mph with a peak of 76 mph on December 18 at 0230MST.
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 17, 10:40 AM MST, 1 hour 49 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 1040 AM MST TUE DEC 17 2013 .SHORT TERM...TUESDAY THROUGH THURSDAY NIGHT ALL IS QUIET IN THE WEATHER OFFICE THIS MORNING WITH NO HIGHLIGHTS THIS EVENING. HOWEVER...THIS LOOKS TO BE CHANGING. THE PERSISTENT WIND HAS QUIETED FOR NOW IN THE WORLDS WINDIEST PLACE...CLARK. HOWEVER...THERE ARE SOME INDICATIONS IT COULD INCREASE AGAIN LATER THIS AFTERNOON AND TONIGHT. THERE IS STILL A GOOD PRESSURE GRADIENT AS WELL AS A THERMAL GRADIENT ACROSS THE AREA. HOWEVER...THE JET SUPPORT IS NOT THERE AS IT HAS BEEN FOR PREVIOUS EVENTS. 700 MILLIBAR WINDS ARE BORDERLINE AS WELL...GENERALLY AROUND 50 KNOTS AT THE MAXIMUM. SO WE WERE ONE THE FENCE AS TO WHAT TO DO. FOR NOW...WE WILL ISSUE A HIGH WIND WATCH SINCE THERE IS AT LEAST A CHANCE OF REACHING CRITERIA. WE WILL LET THE DAY SHIFT DECIDE ON ANY UPGRADE. AS FOR THE REST OF THE AREA...IT LOOKS FAIRLY TRANQUIL WITH ABOVE NORMAL TEMPERATURES. THERE WILL BE SOME MID TO HIGH LEVEL CLOUDS PASSING THROUGH AS WELL BUT NO PRECIPITATION IS EXPECTED. TEMPERATURES TODAY...LIKE YESTERDAY...WILL BE TRICKY DEPENDING ON WIND...ESPECIALLY IN PLACES LIKE RIVERTON. FOR NOW WE KEPT THEM A BIT LOWER SINCE AS I HAVE STATED BEFORE...IF IT GETS WARMER MOST PEOPLE WILL BE HAPPY. THE WIND WILL CONTINUE AROUND NATRONA COUNTY AS WELL BUT NOTHING UNUSUAL FOR DECEMBER. EXPECT THE SAME FOR WEDNESDAY AS WELL...WITH LESS WIND IN THE AREAS AROUND CLARK AS THE CONDITIONS FOR HIGH WIND THERE EASE A BIT. NOW FOR THE SECOND DILEMMA AS WINTER WILL MAKE A RETURN TO THE COWBOY STATE. A COLD FRONT WILL DROP SOUTHWARD THROUGH MONTANA AND MOVE INTO NORTHWESTERN WYOMING ON WEDNESDAY NIGHT AND DROP SOUTHWARD THROUGH THE STATE ON THURSDAY. THE MODELS...WHICH HAD BEEN TRENDING WARMER HAVE NOW TRENDED A BIT COLDER. NOT AS COLD AS THE LAST COLD OUTBREAK...BUT COLDER THAN THE LAST RUNS. MODELS NOW SHOW WITH THE STRONG COLD ADVECTION TEMPERATURES MAY HOLD STEADY OR FALL DURING THE DAY FOR THURSDAY AFTER THE FRONTAL PASSAGE ACROSS MANY AREAS WITH A COLD NIGHT FOR THURSDAY NIGHT. THE NEXT QUESTION IS THE POTENTIAL FOR SNOW. MODE ARE FAIRLY CONSISTENT THROUGH 06Z THURSDAY WITH SOME TIMING DIFFERENCES ARRIVING AFTER THAT. THE NAM APPEARS FASTER IN MOVING THE FRONT THROUGH BY ABOUT 6 HOURS THAN THE GFS IS. THE NAM HOWEVER...DOES HAVE BETTER OMEGA AND A BETTER PERIOD OF SNOW. ACROSS THE NORTHERN PORTION OF THE COUNTY WARNING AREA...FROM THE WIND RIVER RANGE AND NORTH...IT STILL LOOKS LIKE A FAIRLY QUICK EVENT WITH AMOUNTS STAYING WELL BELOW WARNING LEVELS AND POSSIBLY NOT EVEN REACHING ADVISORY LEVEL. A NEW WRINKLE SHOWN BY BOTH THE NAM AND GFS SHOW SOME MOISTURE BEING INTRODUCED INTO SOUTHERN WYOMING WITH SOME SOUTHWEST FLOW ON THURSDAY. AT THE SAME TIME...SOME UPPER LEVEL DIVERGENCE AND THE LEFT FRONT QUAD OF A JET STREAK PASSING CLOSE TO THE AREA MAY HELP ENHANCE SNOWFALL. AS A RESULT WE BUMPED UP POPS AND QPF ACROSS THAT AREA. SNOWFALL SHOULD BE ENDING BY LATER THURSDAY NIGHT AS THE FRONT MOVES AWAY TO THE SOUTH. .LONG TERM...FRIDAY THROUGH TUESDAY CLOSED UPPER LOW WILL MOVE ACROSS THE SOUTHERN ROCKIES INTO THE SOUTHERN PLAINS FRIDAY AND SATURDAY. DEFORMATION AREA WILL PUSH PRECIPITATION SHIELD WITH THIS SYSTEM MOSTLY SOUTH AND EAST OF THE AREA ON FRIDAY AS SURFACE HIGH PRESSURE BUILDS INTO THE CENTRAL PLAINS. WE SHOULD SEE A SLIGHT REBOUND IN TEMPERATURES ACROSS THE CENTRALAND EAST WITH SOME SUN AND WEAK LEE SIDE SURFACE TROUGH ON FRIDAY. A COUPLE OF CLIPPERS WILL FOLLOW IN NW FLOW...THE FIRST ON FRIDAY NIGHT WILL BRING A SHOT OF SNOW MAINLY TO THE NORTHERN AND WESTERN MOUNTAINS. THE SECOND CLIPPER WILL BE ACCOMPANIED BY A STRONGER COLD FRONT EAST OF THE DIVIDE LATE SATURDAY/SATURDAY NIGHT THAT WILL BRING CHANCES OF SNOW TO THESE PARTS. NW FLOW WILL FOLLOW THROUGH CHRISTMAS EVE WITH MILDER AND DRY WEATHER OVER CENTRAL AND SOUTHERN AREAS SUNDAY AND MONDAY WITH BREEZY TO WINDY AREAS. CHANCES OF SNOW WILL CONTINUE ACROSS THE WESTERN MOUNTAINS WITH WARM ADVECTION IN MOIST NW FLOW. GFS AND ECMWF INDICATE A FAIRLY STRONG CLIPPER PUSHING SE ACROSS THE AREA IN THE MONDAY NIGHT/TUESDAY TIMEFRAME WITH SIGNIFICANT DIFFERENCES IN THE TIMING AND STRENGTH OF THIS SYSTEM. CONFIDENCE LOW IN ANY DETERMINISTIC MODELS DEPICTION OF THE DETAILS THIS FAR OUT...AND FORECAST KEEPS HIGH POPS IN THE WESTERN MOUNTAINS...SPREADING SOME CHANCES OF SNOW AND COOLER TEMPERATURES EAST OF THE DIVIDE ON CHRISTMAS EVE. EITHER WAY...THIS LOOKS TO BE A QUICK-MOVING SYSTEM AND NOT A SIGNIFICANT SNOW PRODUCER ON THIS SIDE OF THE DIVIDE. A DRIER NW FLOW SHOULD FOLLOW THIS SYSTEM ON CHRISTMAS DAY WITH POSSIBLY SOME AREAS OF SNOW LINGERING IN THE NW MOUNTAINS. && .AVIATION.../12Z ISSUANCE/ VFR CONDITIONS WILL OCCUR TODAY THROUGH WEDNESDAY. HIGH CLOUDS WILL INCREASE WEDNESDAY. GUSTY WIND WILL OCCUR AT SOME TERMINAL SITES INCLUDING KCPR...KRKS AND KCOD. && .FIRE WEATHER... A DRY NORTHWEST FLOW WILL REMAIN OVER THE AREA. THIS PATTERN WILL CONTINUE GUSTY TO BREEZY CONDITIONS ACROSS FAVORED LOCATIONS...ESPECIALLY THE WIND CORRIDOR BETWEEN ROCK SPRINGS AND CASPER...EAST OF ABSAROKAS AND ACROSS CENTRAL WYOMING. TEMPERATURES SHOULD BE SIMILAR ON TODAY TO THOSE EXPERIENCED YESTERDAY...WITH SOME AREAS POTENTIALLY WARMING A BIT. WIND SHOULD BE ABLE TO RELAX LATE TUESDAY AS THE PRESSURE GRADIENT FINALLY BEGINS TO RELAX OVER THE FORECAST AREA. A COLD FRONT WILL DROP SOUTHWARD ACROSS THE STATE WEDNESDAY NIGHT AND THURSDAY AND BRING COLDER TEMPERATURES AND A GOOD CHANCE OF SNOW. && .RIW WATCHES/WARNINGS/ADVISORIES... HIGH WIND WATCH FROM THIS AFTERNOON THROUGH WEDNESDAY MORNING WYZ003. && SHORT TERM...HATTINGS LONG TERM...AEM AVIATION...AR/LIPSON FIRE WEATHER...HATTINGS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 500 AM MST TUE DEC 17 2013 WYZ001>020-022>030-1812100- 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 TUE DEC 17 2013 ...HIGH WIND WATCH FOR THE CODY FOOTHILLS LATE THIS AFTERNOON THROUGH WEDNESDAY MORNING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT STRONG WINDS OF 30 TO 40 MPH WITH GUSTS TO 60 MPH ARE POSSIBLE IN THE CODY FOOTHILLS LATE THIS AFTERNOON THROUGH WEDNESDAY MORNING. PLEASE SEE HIGH WIND WATCH FOR THE LATEST INFORMATION. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THURSDAY AND THURSDAY NIGHT...A COLD FRONT WILL SPREAD SNOW ACROSS CENTRAL AND SOUTHERN WYOMING ON THURSDAY. SNOW AND GUSTY NORTH WIND WILL LIKELY RESULT IN WINTER DRIVING CONDITIONS WITH LIMITED VISIBILITY IN SNOW AND BLOWING SNOW ACROSS THESE AREAS. THESE WINTER CONDITIONS MAY ESPECIALLY IMPACT THE INTERSTATE 80 CORRIDOR THROUGH THURSDAY NIGHT. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT WIND SPEEDS GREATER THAN 45 MPH... OR ANY WIND DAMAGE. THANK YOU. TEAM RIVERTON
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 1200 PM MST TUE DEC 17 2013 WYZ020-022-180300- CASPER MOUNTAIN-NATRONA COUNTY LOWER ELEVATIONS- 1200 PM MST TUE DEC 17 2013 ...VERY WINDY THIS AFTERNOON AND TONIGHT... SOUTHWEST WIND WILL INCREASE THROUGH THE DAY WITH WIND SPEEDS OF 25 TO 35 MPH WITH GUSTS NEAR 45 TO 50 MPH EXPECTED THIS AFTERNOON AND TONIGHT. WIND GUSTS COULD BE HIGHER ALONG OUTER DRIVE ON THE SOUTHEAST SIDE OF CASPER. DRIVE WITH CARE AS THESE WINDS MAY CAUSE LOSS OF VEHICLE CONTROL. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
The wind sensors at Clark and 8 miles SSW of Clark recorded high wind gusts. The maximum gust was 76 mph at DW6841 near Clark at 0230MST December 18.
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: 481266.