Mid-atmospheric winds and a tightening surface pressure gradient ahead of an advancing cold front combined to produce strong wind across eastern Sweetwater County. A peak wind of 59 mph blew at the Rock Springs-Sweetwater County Airport on the evening of December 23.
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The episode as NWS RIW wrote it up.
Mid-atmospheric winds and a tightening surface pressure gradient ahead of an advancing cold front combined to produce strong wind across eastern Sweetwater County. A peak wind of 59 mph blew at the Rock Springs-Sweetwater County Airport on the evening of December 23. The highest recorded wind was 62 mph at Snow Springs Creek RAWS Christmas Eve morning.
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 23, 5:05 PM MST, 4 hours 38 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 505 PM MST MON DEC 23 2013 .SHORT TERM...TONIGHT THROUGH TUESDAY A VIGOROUS FAST MOVING SHORTWAVE WILL BE SWINGING ACROSS WYOMING TONIGHT. THE BACK EDGE OF THIS SYSTEM EXTENDS FROM NORTHWEST MONTANA TO NORTHERN IDAHO. AT THE RATE THIS FEATURE IS MOVING...THE SNOW SHOULD END IN NORTHWEST AND WESTERN WYOMING...WHERE SNOW ADVISORY AMOUNTS ARE EXPECTED TONIGHT THROUGH TUESDAY MORNING...AROUND SUNRISE TUESDAY BUT NOT BEFORE ONE LAST BLAST OF SNOW AND WIND WHEN THE ASSOCIATED STRONG PACIFIC COLD FRONT SWINGS ACROSS THE AREA. A FROUDE NUMBER OF ONE AND A CRITICAL LAYER OBSERVED OVER THE CODY FOOTHILLS AS WELL AS A DECENT PRESSURE GRADIENT AHEAD OF THE AFOREMENTIONED WEATHER FEATURE JUSTIFIES THE CONTINUANCE OF A HIGH WIND WARNING FOR THE CODY FOOTHILLS THROUGH 10Z TONIGHT. SOME AREAS WILL SEE STEADY TEMPERATURES TONIGHT AS THE STRONG GRADIENT AND RESULTANT WIND KEEPS THE AIRMASS MIXED ALONG THE SOUTHERN WIND CORRIDOR AND THE CODY FOOTHILLS. AS THE TROUGH EXITS TO THE SOUTHEAST TUESDAY...SNOW WILL END FROM NORTHWEST TO SOUTHEAST TUESDAY. .LONG TERM...TUESDAY NIGHT THROUGH MONDAY OUR TUESDAY SHORTWAVE WILL HAVE ALREADY EXITED OUR AREA BY TUESDAY EVENING BUT IT LOOKS LIKE THERE WILL BE ENOUGH MID LEVEL FLOW AND SURFACE GRADIENT TO KEEP SOME STIFF W TO NW WINDS INTO THE EVENING AND IN SOME AREAS LIKE THE MTNS AND EAST SLOPE FOOTHILLS...THROUGH THE NIGHT TUESDAY. THE NW FAVORED AREAS MAY CONTINUE WELL INTO THE NIGHT AFFECTING TEMPERATURES AND FOG FORMATION. THE UPPER GREEN MAY SEE A NW WIND TUESDAY NIGHT AS WELL AS THE WIND RIVER BASIN DOWN TO NEAR RIVERTON. WINDS WILL LIKELY DIE OFF EARLY ENOUGH IN THE LOWEST ELEVATIONS OF THE WIND RIVER BASIN FOR POTENTIAL FOG FORMATION WEDNESDAY MORNING. BITTER COLD WHERE WINDS DROP OFF AND STILL QUITE COLD IN THE WINDY AREAS DUE TO THE WIND CHILLS. OTHERWISE...A DRY PERIOD WITH CONTINUED GUSTY GAP FLOW AND WIND CORRIDOR WINDS WITH INCREASING INVERSIONS FOR THE BASIN AND WRN VALLEYS. TEMPERATURES WILL REMAIN QUITE CHILLY WED AND THU AS INVERSIONS REDEVELOP IN THESE BASINS/VALLEYS BUT WARM THROUGH THE PERIOD IN THE MOUNTAINS AND WINDY AREAS. MEDIUM RANGE PERIOD WILL BE DOMINATED BY A FAIRLY STRONG NW FLOW WITH SEVERAL EMBEDDED SE MOVING SHORTWAVES THAT WE'LL HAVE TO WATCH CLOSELY. THE FIRST ONE OVER THE WEEKEND...ACTUALLY A POTENTIAL ONE TWO PUNCH...IS CURRENTLY JUST SOUTH OF THE WEST END OF THE ALEUTIANS. THE SECOND ONE FOR THE END OF THE PERIOD NEXT MONDAY IS JUST HEADING OFF THE EASTERN END OF ASIA. THE GFS AND GEM ARE MORE AGGRESSIVE AND FURTHER WEST WITH THESE WEEKEND SHORTWAVES COMPARED TO THE LAST COUPLE RUNS OF THE ECMWF. WITH THE EXPECTED RIDGE AXIS REMAINING WELL TO THE WEST...THE FURTHER WEST SOLUTION IS PREFERRED SO MINIMAL CHANGES TO THE GOING FORECAST FOR NOW. KEEPING A CHANCE OF SNOW ACROSS THE NORTH AND MOST OF THE FAR EAST FOR NOW. FAIRLY STRONG MID LEVEL FLOW AND AT LEAST MODERATE SURFACE GRADIENT AND LEE SIDE THERMAL GRADIENT WILL LIKELY LEAD TO CONTINUED WINDY CONDITIONS AT TIMES FOR THE WIND CORRIDOR...EAST SLOPE OF THE MOUNTAINS AND CODY FOOTHILL GAP FLOW AREAS. BASINS/VALLEYS LOOK LIKE THEY'LL STRUGGLE TO MIX YET FRIDAY SO WILL KEEP TEMPERATURES CLOSER TO COLDER ECMX MOS GUIDANCE WHICH IS A GOOD 15 DEGREES COLDER THAN THE MEX GUIDANCE. STILL WORTH WATCHING CLOSELY WITH WINDS IN THE FOOTHILLS AND MODERATE GRADIENT WHICH HAS THE POTENTIAL AT LEAST TO MIX THE BASINS OUT. IF IT DOES...FORECAST WILL BE TOO COLD BY AT LEAST 15 DEGREES. MIXING IS MUCH MORE LIKELY SATURDAY WITH FIRST SHORTWAVE DROPPING SE ACROSS THE AREA BUT STRONG COLD AIR ADVECTION WILL KEEP IT QUITE CHILLY WITH EXPECTED -10 TO -15C AIR ACROSS THE CWFA. CONTINUED CHILLY SUNDAY. WARMER MID LEVEL TEMPERATURES ON MONDAY WITH STRONG NW FLOW ALOFT. LEE SIDE TROUGH AND INCREASING SURFACE GRADIENT SHOULD RESULT IN PLENTY OF WIND FOR THE WIND CORRIDOR...MOUNTAINS AND EAST SLOPE AND CODY FOOTHILLS. BASINS WILL HAVE TO BE WATCHED CLOSELY AS TO WHETHER A NEWLY DEVELOPED INVERSION WILL HOLD WITH THAT MUCH POTENTIAL SURFACE GRADIENT AND NW FLOW ALOFT. STILL A LONG WAY OFF BUT FOR NOW...I HAD TO ADJUST A LOT OF THE WIND UPWARD IN THE MEDIUM RANGE AS NO GUIDANCE...AS USUAL...DOES A GOOD JOB OF HANDLING OUR WINDS. && .AVIATION.../00Z ISSUANCE/ WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES A MOIST NORTHWEST FLOW...AHEAD OF A QUICK MOVING STORM SYSTEM WILL RESULT IN CONDITIONS TO DETERIORATE...ESPECIALLY ACROSS NORTHWEST WYOMING...INCLUDING AT KJAC TERMINAL WITH INCREASING WINDS...MOUNTAIN TOP TURBULENCE...AND HEAVIER SNOWFALL. SOME SNOW SHOWER ACTIVITY AND MVFR/BRIEF IFR CONDITIONS WILL BE POSSIBLE FARTHER SOUTHEAST AFFECTING KBPI...KPNA AND KRKS TERMINALS...BUT PROLONGED PERIODS OF MVFR/IFR CONDITIONS ARE NOT EXPECTED. WESTERN MOUNTAINS WILL BE OBSCURED MUCH IF NOT ALL OF THE TIME. EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES ALTHOUGH SOME LIGHT SNOW/FLURRIES AND ASSOCIATED MVFR/IFR CEILINGS COULD OCCUR IN THE MOUNTAINS TODAY...THE MAIN ISSUE WILL BE INCREASING WINDS ON THE LEE SIDE OF THE MOUNTAIN RANGES...AND THE WIND CORRIDORS. TRAPPED BASINS...AWAY FROM THE FOOTHILLS WILL KEEP MAINLY LIGHT WINDS TONIGHT. TONIGHT...A QUICK MOVING STORM SYSTEM WILL RESULT IN A BETTER CHANCE OF SNOW SHOWERS OVER THE MOUNTAINS WITH POSSIBLY SOME ACTIVITY SPILLING INTO THE LOWER ELEVATIONS. HOWEVER THE MAIN CONCERN EAST OF THE DIVIDE WILL BE STRONG WINDS AND MOUNTAIN AND ADJACENT FOOTHILL TURBULENCE TONIGHT WITH THIS STORM SYSTEM. SOME OF THE STRONG WINDS COULD MIX INTO THE CODY FOOTHILLS TONIGHT. TAF SITES ARE EXPECTED TO HAVE MAINLY VFR CONDITIONS THROUGHOUT THE PERIOD. && .FIRE WEATHER... SIGNIFICANT SNOWFALL IS EXPECTED IN FAR WESTERN WYOMING TONIGHT AND TUESDAY MORNING. BRISK WEST SOUTHWEST WINDS ARE EXPECTED FROM ROCK SPRINGS TO CASPER TONIGHT AND TUESDAY MORNING AS WELL AS ALONG THE EAST SIDE OF THE CONTINENTAL DIVIDE. SOME AREAS THAT EXPERIENCE WIND WILL EXPERIENCE STEADY OR RISING TEMPERATURES THROUGH TONIGHT, WINDS WILL BE ESPECIALLY STRONG IN FIRE ZONES 286 AND 276. && .RIW WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 8 AM MST TUESDAY WYZ001-002-012-013-023. HIGH WIND WARNING UNTIL 3 AM MST TUESDAY WYZ003. && SHORT TERM...LIPSON LONG TERM...SKRBAC AVIATION...LIPSON FIRE WEATHER...LIPSON
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 500 PM MST MON DEC 23 2013 WYZ001>020-022>030-241300- 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 PM MST MON DEC 23 2013 ...A HIGH WIND WARNING AS BEEN ISSUED FOR THE CODY FOOTHILLS TONIGHT... ...WINTER WEATHER ADVISORY FOR MUCH OF THE FAR WEST THROUGH 8 AM TUESDAY... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TONIGHT SIGNIFICANT SNOW AND BLOWING SNOW ACROSS FAR WESTERN WYOMING...ALONG WITH VERY STRONG WIND IN PORTIONS OF THE CODY FOOTHILLS. OTHERWISE...WINDY WEST TO SOUTHWEST WINDS WILL OCCUR IN FAVORED WIND CORRIDORS TONIGHT...AS WELL AS ALONG THE LEE SIDE OF MOUNTAIN RANGES. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY TUESDAY...BREEZY TO WINDY WEST TO NORTHWEST WINDS ACROSS MUCH OF THE AREA...WITH THE STRONGEST WINDS OVER SOUTHERN LINCOLN AND SWEETWATER COUNTY TUESDAY MORNING. ALSO...A BURST OF SNOWFALL COULD OCCUR TUESDAY MORNING AS A COLD FRONT PULLS QUICKLY THROUGH THE AREA...WITH BRIEF...BUT SIGNIFICANT REDUCTIONS OF VISIBILITY. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT SNOW AMOUNTS AND ANY WIND GUSTS OVER 50 MPH OR WIND DAMAGE. THANK YOU. TEAM RIVERTON
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE RIVERTON WY 409 PM MST MON DEC 23 2013 WYZ027>030-241000- EAST SWEETWATER COUNTY-FLAMING GORGE-ROCK SPRINGS AND GREEN RIVER- SOUTH LINCOLN COUNTY- 409 PM MST MON DEC 23 2013 WEST TO SOUTHWEST WINDS BETWEEN 20 AND 35 MPH WILL BE COMMON THROUGH TUESDAY MORNING...ACROSS SOUTHERN LINCOLN COUNTY...EAST ACROSS ALL OF SWEETWATER COUNTY. A FEW GUSTS AROUND 55 MPH COULD OCCUR IN FAVORED AREAS BETWEEN 3 AM AND 9 AM TUESDAY...AS A STRONG PACIFIC COLD FRONT MOVES EAST ACROSS THE AREA. LIGHTWEIGHT AND HIGH PROFILE VEHICLES SHOULD BE ESPECIALLY CAUTIOUS IF TRAVELING THROUGH THESE AREAS TONIGHT. WYZ014-015-018-019-241000- GREEN MOUNTAINS AND RATTLESNAKE RANGE-LANDER FOOTHILLS- WIND RIVER MOUNTAINS EAST-WIND RIVER MOUNTAINS WEST- 409 PM MST MON DEC 23 2013 SOUTHWEST WINDS BETWEEN 25 AND 35 MPH...WILL BE COMMON TONIGHT ACROSS SOUTH PASS...AND MUCH OF SOUTHEAST FREMONT COUNTY...INCLUDING ALONG HIGHWAY 287. A FEW GUSTS BETWEEN 50 AND 60 MPH COULD OCCUR. THE STRONG WINDS COULD ALSO CAUSE SOME BLOWING SNOW OVER SOUTH PASS. LIGHTWEIGHT AND HIGH PROFILE VEHICLES SHOULD BE ESPECIALLY CAUTIOUS IF TRAVELING THROUGH THESE AREAS TONIGHT. WYZ016-241000- UPPER WIND RIVER BASIN- 409 PM MST MON DEC 23 2013 WEST TO NORTHWEST WINDS BETWEEN 20 AND 35 MPH...WILL OCCUR ACROSS THE UPPER WIND RIVER BASIN...INCLUDING CROWHEART AND DUBOIS. TRAVEL WILL BE VERY DIFFICULT OVER TOGWOTEE PASS TONIGHT DUE TO FALLING AND BLOWING SNOW...CAUSING SLICK AND HAZARDOUS ROAD CONDITIONS WITH SEVERELY LIMITED VISIBILITY AT TIMES. THOSE WHO PLAN ON TRAVELING...ESPECIALLY OVER TOGWOTEE PASS TONIGHT ARE ENCOURAGED TO CHECK THE ROAD CONDITIONS BEFORE LEAVING. WYZ020-022-241000- CASPER MOUNTAIN-NATRONA COUNTY LOWER ELEVATIONS- 409 PM MST MON DEC 23 2013 SOUTHWEST WINDS WILL BE ON THE INCREASE THIS EVENING...WITH WINDS BETWEEN 25 AND 35 MPH COMMON ACROSS MUCH OF NATRONA COUNTY TONIGHT. A FEW GUSTS TO 45 MPH ARE LIKELY. LIGHTWEIGHT AND HIGH PROFILE VEHICLES SHOULD BE CAUTIOUS IF TRAVELING THROUGH NATRONA COUNTY TONIGHT. 21
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
A wind gust of 62 mph was recorded at Snow Springs Creek. A 58 mph wind gust was also recorded at the Rock Springs Airport at 2143MST December 23.
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: 481287.