A potent winter storm moved out of Utah and into southern Colorado setting the stage for heavy snow on Casper Mountain. There were numerous reports of snowfall ranging from 1 to 2 feet, including 22 inches at the Hogadon Ski Area and an estimated 23 inches at the Casper Mountain SNOTEL.
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The episode as NWS RIW wrote it up.
A potent winter storm moved out of Utah and into southern Colorado setting the stage for heavy snow on Casper Mountain. There were numerous reports of snowfall ranging from 1 to 2 feet, including 22 inches at the Hogadon Ski Area and an estimated 23 inches at the Casper Mountain SNOTEL. Isolated reports of up to 3 feet were received from spotters on Casper Mountain and nearby Muddy Mountain.
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 Feb 23, 10:57 AM MST, 1 hour 3 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE RIVERTON WY 1057 AM MST SAT FEB 23 2013 .SHORT TERM...TODAY THROUGH MONDAY NIGHT SNOWFALL CONTINUES TO SPREAD ACROSS WESTERN WYOMING THIS MORNING. ONGOING SNOWFALL AND THE SYSTEM WHICH THEY AREA ASSOCIATED WITH ARE THE MAIN FOCUS OF THE SHORT TERM PERIOD. AS INDICATED IN EARLIER FORECASTS...SNOWFALL WILL CONTINUE THROUGH THE DAY TODAY...WITH PERIODS OF MODERATE SNOWFALL ACROSS THE WESTERN MOUNTAINS. A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR THESE AREAS THROUGH THE AFTERNOON HOURS. THE TROUGH BRINGING THIS WIDESPREAD SNOWFALL WEST OF THE DIVIDE WILL MOVE EAST OF THE DIVIDE THIS EVENING. MODELS CONTINUE TO INDICATE THE POTENTIAL FOR MODERATE SNOWFALL AMOUNTS ACROSS CENTRAL AND EASTERN WYOMING THROUGH THE EVENING HOURS...PRIMARILY DURING THE EVENING HOURS. NATIONAL GUIDANCE DEMONSTRATES THE POTENTIAL FOR A QUICK 2 TO 5 INCHES OF SNOWFALL ACROSS PORTIONS OF SOUTHEASTERN FREMONT AND NATRONA COUNTIES. THIS PUSH SEEMS ESPECIALLY FAVORABLE OVER UPSLOPE FAVORED AREAS. HAVE INCREASED PRECIP PROBABILITIES A BIT ACROSS THE OWL CREEKS AROUND THERMOPOLIS...THOUGH THE INCREASE WAS NOT OVERLY SIGNIFICANT. BECAUSE OF THE SPEED AT WHICH THIS SYSTEM IS ANTICIPATED TO MOVE...AND SOME WARMING SURFACE TEMPERATURES AHEAD OF THE SYSTEM TODAY...CONFIDENCE IS NOT HIGH ENOUGH TO ADD ANY WINTER WEATHER HIGHLIGHTS AT THIS TIME. AS SNOWFALL BEGINS TO MOVE TOWARDS THE DIVIDE...THE BEHAVIOR CAN BE EVALUATED FOR ANY NEEDED HIGHLIGHTS. OTHERWISE...THIS SYSTEM IS EXPECTED TO GENERALLY MOVE OUT OF THE AREA BY LATE SUNDAY AFTERNOON...WITH A NORTH TO NORTHWEST FLOW DEVELOPING OVER THE AREA. SOME MOISTURE EMBEDDED IN THIS NORTHERLY FLOW MAY BE ENOUGH TO KEEP LIGHT SNOWFALL ACROSS THE WESTERN MOUNTAINS...THOUGH NO SIGNIFICANT SNOWFALL ACCUMULATION IS EXPECTED. MODELS THEN SUGGEST ANOTHER...STRONGER SLUG OF MOISTURE TO MOVE ACROSS WESTERN WYOMING BY MONDAY AFTERNOON. MODELS IN SOMEWHAT FAIR AGREEMENT THAT SNOWFALL ASSOCIATED WITH THIS UPCOMING TROUGH MAY MOVE EAST OF THE DIVIDE MONDAY EVENING. SPECIFIC AREAS RECEIVING THE BULK OF THE MOISTURE REMAINS AT QUESTION...AND WILL CONTINUE TO BE EVALUATED. .LONG TERM...TUESDAY THROUGH SATURDAY THE LONG TERM PERIOD BEGINS WITH A FAIRLY ACTIVE AND WET PATTERN AS A WAVE MOVES THROUGH THE REGION...BRINGING AT LEAST A SLIGHT CHANCE OF SNOW TO AREAS BOTH EAST AND WEST OF THE DIVIDE...WITH A CHANCE TO LIKELY POPS ACROSS THE WESTERN MOUNTAINS AND ALONG THE I25 CORRIDOR AND OTHER FAVORED UPSLOPE AREAS EARLY TUESDAY THROUGH TUESDAY EVENING. THERE WILL BE A BRIEF BREAK AFTER THE FIRST SYSTEM MOVES THROUGH BEFORE ANOTHER ONE QUICKLY APPROACHES FROM THE NORTHWEST...EXPECTED TO MOVE THROUGH ON WEDNESDAY EVENING. THE OPERATIONAL EUROPEAN IS BY FAR THE DRIEST WITH THIS SECOND SYSTEM AND IS THE OUTLIER. SOME SNOW IS EXPECTED ACROSS THE WEST AND NORTH BY THE GFS...GEM AND DGEX...SLIGHT CHANCE POPS WERE INTRODUCED ACROSS THE ENTIRE CWA ON THURSDAY GIVEN THE MODEL UNCERTAINTIES AND POTENTIAL FOR CSI BANDING AS LAPSE RATES ARE FORECAST TO EXCEED 7.5 DEG/KM ACROSS MOST OF THE CWA IN THE AFTERNOON. RIDGING BUILDS IN THEREAFTER WITH SEASONAL TEMPERATURES AND DRY WEATHER EXPECTED FOR THE REMAINDER OF THE PERIOD...WITH THE EXCEPTION OF A FEW FLURRIES POSSIBLE IN THE REMNANTS OF MOISTURE ACROSS THE WEST. && .AVIATION.../18Z ISSUANCE/ SNOW WILL OCCUR ACROSS WESTERN WY WITH MVFR TO IFR CONDITIONS... LOCAL LIFR CONDITIONS MAY OCCUR. AFTER 21Z CONDITIONS IN THE WEST AND SOUTHWEST WILL GRADUALLY IMPROVE. LINGERING SNOW SHOWERS WILL OCCUR THROUGH 12Z SUNDAY IN THE WEST...MAINLY OVER AND NEAR THE MOUNTAINS. A COLD FRONT AND WEATHER SYSTEM WILL IMPACT NORTHERN WY FROM 19Z THROUGH 00Z...BRINGING AREAS OF SNOW AND MVFR TO IFR CONDITIONS. THEN THE COLD FRONT AND SNOW WILL MOVE SOUTH INTO FREMONT COUNTY AROUND 00Z AND INTO NATRONA COUNTY BY 03Z. THE SNOW AND ASSOCIATED LOW CIGS WILL CONTINUE IN FREMONT COUNTY UNTIL AROUND 09Z TONIGHT AND UNTIL 15Z IN NATRONA COUNTY. THE SNOW AND LOW CLOUDS WILL BRING MVFR TO IFR CONDITIONS...LOCAL LIFR CONDITIONS WILL OCCUR AROUND THE KCPR AND KLND AIRPORTS. CONDITIONS IN CENTRAL WY WILL GRADUALLY IMPROVE AFTER 09Z SUNDAY FROM WEST TO EAST. && .FIRE WEATHER... SNOWFALL WILL CONTINUE WEST OF THE DIVIDE INTO THE AFTERNOON HOURS. MODERATE SNOWFALL IS EXPECTED WITH THIS SYSTEM...ADDITIONAL DETAILS CAN BE FOUND IN OUR WINTER WEATHER HIGHLIGHTS. SNOW IS EXPECTED TO THEN MOVE EAST OF THE DIVIDE THIS EVENING...IMPACTING PORTIONS OF FREMONT AND NATRONA COUNTIES. GUSTY WIND WILL ACCOMPANY THIS SYSTEM...CREATING SOME AREAS OF BLOWING SNOW THROUGHOUT THE DAY. CONDITIONS ARE EXPECTED TO IMPROVE THROUGH THE DAY ON SUNDAY...WITH ANOTHER WINTRY SYSTEM THEN POSSIBLE MONDAY AND MONDAY NIGHT. && .RIW WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON WYZ001-012-013-023-024. && SHORT TERM...BRANHAM LONG TERM...ALLEN AVIATION...LIPSON FIRE WEATHER...BRANHAM
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 434 AM MST SAT FEB 23 2013 WYZ001>020-022>030-241135- 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- 434 AM MST SAT FEB 23 2013 ...WINTER WEATHER ADVISORY FOR FAR WESTERN WYOMING TODAY... ...ACCUMULATING SNOWFALL POSSIBLE FROM LANDER TO CASPER THIS EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT MODERATE TO HEAVY SNOWFALL WILL REMAIN ACROSS WESTERN WYOMING THROUGH THE AFTERNOON HOURS TODAY. PLEASE VISIT THE WINTER WEATHER ADVISORY PRODUCT FOR ADDITIONAL INFORMATION REGARDING ACCUMULATIONS AND TIMING. SNOWFALL WILL MOVE EAST OF THE DIVIDE THIS EVENING...BRINGING LIGHT TO MODERATE SNOWFALL ACROSS CENTRAL AND EASTERN WYOMING. SNOWFALL OF 1 TO 4 INCHES WILL BE POSSIBLE THROUGH THE LATE EVENING HOURS BEFORE SNOWFALL BEGINS TO WEAKEN. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY MONDAY...ANOTHER ROUND OF LIGHT TO MODERATE SNOWFALL MAY IMPACT THE WESTERN MOUNTAINS BEGINNING MONDAY MORNING. THIS MAY AGAIN RESULT IN SNOW PACKED ROADWAYS ACROSS WESTERN WYOMING. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT SNOWFALL AMOUNTS. THANK YOU. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
1 winter storm. Local standard time, as filed.
Hogadon Ski Area on Casper Mountain reported 22 inches of new Snow. The Casper Mountain SNOTEL estimated 23 inches of new snow.
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, February 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: 427676.