Pacific low pressure moved southeast from the Great Basin through Colorado, bringing dynamically driven snow followed by localized upslope enhancement as the low deepened over Colorado. Snowfall of 18 inches occurred on Casper Mountain and up to a foot fell in the higher elevations south of Rock Springs around Quaking Aspen Mountain.
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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.
Pacific low pressure moved southeast from the Great Basin through Colorado, bringing dynamically driven snow followed by localized upslope enhancement as the low deepened over Colorado. Snowfall of 18 inches occurred on Casper Mountain and up to a foot fell in the higher elevations south of Rock Springs around Quaking Aspen Mountain. Reports of five to seven inches of snow were received from near the Granite Mountains in Fremont and Natrona counties.
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 Mar 22, 2:46 PM MST, 6 hours 14 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 346 PM MDT MON MAR 22 2010 .SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT A PACIFIC STORM SYSTEM MOVING ACROSS THE PACIFIC NORTHWEST...DIGGING INTO THE GREAT BASIN WILL CONTINUE TO MOVE THROUGH THE GREAT BASIN...AND THE NORTHERN AND CENTRAL ROCKIES TONIGHT AND TUESDAY. THE AIR MASS IS UNSTABLE OVER THE AREA WITH WIDESPREAD CONVECTION DEVELOPING. A CLOUD TO GROUND LIGHTNING STRIKE OCCURRED NEAR WORLAND AND PEA SIZE HAIL WAS REPORTED AROUND MEETEETSE THIS AFTERNOON. MUCH OF THE WEST HAS SEEN SNOW WITH THE VALLEYS STARTING AS RAIN AND CHANGING OVER TO SNOW IN JACKSON HOLE. THE SYSTEM HAS GOOD UPPER LEVEL DIVERGENCE...STRONG BAROCLINIC BOUNDARIES WITH DEEP INSTABILITY AND AMPLE MOISTURE. THE MODELS ARE BEING DRIVEN BY THE DEEP CONVECTION AND THERE IS LITTLE CONSISTENCY BETWEEN THEM. THE SYSTEM DOES BECOME MORE UPSLOPE DRIVEN TONIGHT AND TUESDAY MORNING WITH THE FOCUS AREAS ALONG THE NORTH SLOPES OF THE OWL CREEK AND BRIDGER MOUNTAINS...THE ABSAROKA MOUNTAINS...THE BIGHORN MOUNTAINS...THE EAST SLOPES OF THE WIND RIVER MOUNTAINS AND CASPER MOUNTAIN. THERE IS POTENTIAL FOR SIGNIFICANT SNOWFALL IN CENTRAL TO EASTERN SWEETWATER BUT THE MODELS ARE SO DIVERGENT IN THE PRECIPITATION THERE THAT A CONSERVATIVE APPROACH WAS TAKEN. NORTHERN JOHNSON COUNTY IS ALSO A POT ENTAIL AREA TO RECEIVE MUCH HEAVIER SNOW THAN IS IN THE CURRENT FORECAST WITH HUGE MODEL DIVERSITY THERE. TEMPERATURES WILL BE MODERATED TONIGHT WITH MORE WIDESPREAD CLOUD COVER AND PRECIPITATION. TUESDAY WILL BE COLD IN THE SOUTH BUT THE NORTH SHOULD WARM WITH AFTERNOON CLEARING. MODELS SHOW THE MOST CONSISTENCY IN THE ENDING OF THE INTENSE PRECIPITATION AROUND NOON AND RAPIDLY IMPROVING CONDITIONS BETWEEN NOON AND LATE AFTERNOON. THE CASPER AREA/SOUTHERN NATRONA COUNTY AND PORTIONS OF EASTERN SWEETWATER COUNTY HAVE THE BEST POTENTIAL FOR SNOWFALL CONTINUING INTO TUESDAY NIGHT BUT THE GFS IS THE MODEL THAT KEEPS IT GOING WHILE THE NAM CLEARS IT OUT QUICKER. TEMPERATURES WILL DROP IN THE SINGLE DIGITS WITH LOCAL BELOW ZERO LOWS IN THE WEST WEDNESDAY MORNING. FOG WILL BE POSSIBLE IN THE WESTERN VALLEYS AND CENTRAL BASINS. THE CENTRAL BASINS SHOULD HAVE LOWS IN THE TEENS TO UPPER SINGLE DIGITS. REBOUND SHOULD BE AS DRAMATIC WEDNESDAY AND WEDNESDAY NIGHT AS IT WAS AFTER THE LATE WEEK STORM LAST WEEK. SOME LOWS REBOUNDED OVER 30 DEGREES IN 48 HOURS AND EXPECT A STRONG BOUNCE AGAIN WITH WESTERLY FLOW ALOFT DEVELOPING WEDNESDAY AFTERNOON AND EVENING. RELATIVELY LOW CONFIDENCE IN THE DETAILS WITH THIS FORECAST AS MODELS HAVE SO MUCH SPREAD IN POTENTIAL PRECIPITATION LOCATIONS. .LONG TERM...THURSDAY THROUGH MONDAY RIDGE AXIS IS EXPECTED TO WEAKEN THURSDAY ALLOWING A SHORTWAVE TO SKIRT THE NWRN ZONES DURING THE AFTERNOON AND EVENING. THE BIGGER WEATHER CHANGE WILL OCCUR IN THE WEST FRIDAY AND SPREADING EAST OF THE DIVIDE LATE IN THE DAY OR BY FRIDAY EVENING. RAIN WILL QUICKLY CHANGE OVER TO SNOW ACROSS THE CENTRAL AND SERN ZONES FRIDAY EVENING WITH SIGNIFICANT ACCUMULATIONS POSSIBLE DEPENDING ON THE EXACT TRACK AND STRENGTH. HAVE INCREASED POPS EAST OF THE DIVIDE FRIDAY NIGHT INTO THE MID CHANCE TO LOW LIKELY CATEGORY FOR STARTERS. WILL SEE WHAT THE TRENDS LOOK LIKE TONIGHT. THIS SYSTEM IS CURRENTLY OVER KAMCHATKA AND SHOULD HAVE PLENTY OF COLD AIR WITH IT SO THE CHANGEOVER TO SNOW SHOULD NOT BE A PROBLEM FRIDAY NIGHT. STILL A CHANCE THIS SYSTEM COULD DIG TOO FAR S AND IMPACT MORE OF CO AND SERN WY BUT EVEN WITH THAT TRACK...THE STRENGTH OF THIS LOW WOULD LIKELY RESULT IN AT LEAST SOME LIGHT PCPN THIS FAR NORTH. GRADUAL IMPROVEMENT FROM NW TO SE SATURDAY AS A RIDGE ALOFT SLOWLY BUILDS INTO THE INTER-MOUNTAIN WEST FOR THE SECOND HALF OF THE WEEKEND. TEMPERATURES SHOULD REBOUND NICELY ON SUNDAY. NEXT SYSTEM IS EXPECTED TO MOVE INTO THE PACNW EARLY NEXT WEEK WITH THE RIDGE AXIS SHIFTING ACROSS WYOMING ON MONDAY. KEEPING MONDAY DRY FOR NOW UNLESS THE TIMING SPEEDS UP. MILD LOWS COULD BE QUITE POSSIBLE MONDAY MORNING WITH W TO SW BREEZES AND SOME HIGH CLOUDS. MONDAY STILL LOOKS MILD IN MOST AREAS WITH ONLY LEE ENHANCED CLOUDS POSSIBLY HAMPERING SOME LEE SIDE MTN AREAS. && .AVIATION... AN AREA OF LOW PRESSURE WILL MOVE SOUTHEASTWARD FROM SOUTHERN IDAHO TONIGHT ACROSS NORTHERN UTAH AND INTO CENTRAL COLORADO BY LATE IN THE DAY TUESDAY. A COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL EXTEND ALONG A LINE FROM DUBOIS TO LANDER TO CASPER AT 00Z THIS EVENING AND WILL PUSH SOUTHWARD TO THE WYOMING COLORADO BORDER BY MIDNIGHT TONIGHT. THIS FRONT WILL SHIFT THE WINDS TO THE NORTH AND NORTHEAST THIS EVENING ACROSS CENTRAL WYOMING AND WESTERN SWEETWATER COUNTY. MOISTURE AND INSTABILITY AHEAD OF THE COLD FRONT WILL BRING IFR/MVFR CONDITIONS TO KJAC THIS EVENING THROUGH AROUND MIDNIGHT. MOUNTAIN OBSCURATIONS ARE EXPECTED ACROSS THE WESTERN MOUNTAINS THIS EVENING AND THROUGH THE PRE-DAWN HOURS. MOUNTAIN OBSCURATIONS ARE EXPECTED THIS EVENING THROUGH LATE TUESDAY MORNING IN THE BIGHORN MOUNTAINS. UPSLOPE SNOWFALL WILL DEVELOP ACROSS FREMONT COUNTY...NATRONA COUNTY AND EASTERN SWEETWATER COUNTY AFTER MIDNIGHT TONIGHT WITH IFR/MVFR CEILINGS AND VSBYS AFTER MIDNIGHT THROUGH MID TO LATE MORNING WITH KCPR...KLND AND KRIW AFFECTED. COLDER...UNSTABLE AIRMASS WILL ALLOW ISOLATED TO SCATTERED RAIN/SNOW SHOWERS TO DEVELOP TUESDAY LATE MORNING THROUGH THE LATE AFTERNOON ACROSS THE ENTIRE REGION WITH NUMEROUS MOUNTAIN OBSCURATIONS. IMPROVEMENT TO VFR CONDITIONS ARE EXPECTED IN THE LOWER ELEVATIONS LATE TUESDAY MORNING THROUGH TUESDAY AFTERNOON. && .FIRE WEATHER... A PACIFIC STORM SYSTEM WILL BRING INCREASED SHOWERS WITH ISOLATED EARLY EVENING THUNDERSTORMS TO THE AREA. GUSTY WINDS AND LOWERING CLOUD CEILINGS WILL BRING MIXING HEIGHTS DOWN BELOW 1000 FEET WITH POOR SMOKE DISPERSAL. MUCH OF THE AREA WILL SEE PRECIPITATION START AS RAIN AND THE CHANGE OVER TO SNOW. THE MOUNTAINS ABOVE 8000 FEET SHOULD SEE ALL SNOW. MANY MOUNTAIN AREAS WILL SEE 6 TO 12 INCHES OF SNOW WITH AREAS NEAR THE MOUNTAINS MAY SEE 3 TO 6 INCHES. COLDER TEMPERATURES...HIGH HUMIDITY AND LOW STRATUS WILL BE SPREAD OVER THE AREA TUESDAY WITH POOR SMOKE DISPERSAL. && .RIW WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON MDT TUESDAY WYZ015-018>020-022. WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT WYZ001-012. WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON MDT TUESDAY WYZ002-005>009. && SHORT TERM...C.BAKER LONG TERM...SKRBAC AVIATION...SMITH FIRE WEATHER...C.BAKER
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 500 AM MDT MON MAR 22 2010 WYZ001>020-022>030-231100- 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 MDT MON MAR 22 2010 ...WINTER WEATHER ADVISORIES FOR YELLOWSTONE AND GRAND TETON NATIONAL PARKS TODAY... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT SNOW SHOWERS WILL CONTINUE ACROSS THE NORTHWEST MOUNTAINS TODAY WITH AREAS OF LIMITED VISIBILITY ALONG WITH SLICK OR SNOW-PACKED ROADS OVER THE HIGHER PASSES...INCLUDING TETON PASS. SNOWFALL ACROSS THE WEST WILL CONTINUE THROUGH THIS EVENING. SNOWFALL WILL WEAKEN LATE THIS EVENING WITH STORM SNOWFALL TOTALS OF 5 TO 10 INCHES EXPECTED. SHOWER COVERAGE WILL INCREASE THIS AFTERNOON BRINGING RAIN SHOWERS OVER AREAS EAST OF THE CONTINENTAL DIVIDE. ADDITIONALLY...AN UNSTABLE ATMOSPHERE WILL BRING THE POTENTIAL FOR ISOLATED THUNDERSTORMS ACROSS MUCH OF THE AREA TODAY. SHOWER ACTIVITY WILL CONVERT TO SNOWFALL AFTER SUNSET TONIGHT. PERIODS OF MODERATE SNOWFALL MAY BE PRESENT ACROSS THE CENTRAL BASINS THROUGH THE OVERNIGHT HOURS. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY SNOW SHOWERS CONTINUE ON TUESDAY FOR MUCH OF CENTRAL AND WESTERN WYOMING. LOCALLY HEAVY SNOW SHOWERS...AND RAPID ACCUMULATIONS POSSIBLE UNDER PERSISTENT HEAVY SNOW BANDS WILL BE POSSIBLE WITH SNOWFALL ON TUESDAY. SEE WINTER WEATHER ADVISORY PRODUCTS FOR MORE INFORMATION AND STAY TUNED FOR UPDATES ON THIS STORM. ANOTHER STORM SYSTEM MAY AFFECT THE CENTRAL AND SOUTHERN PORTIONS OF THE AREA LATE FRIDAY INTO EARLY SATURDAY. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT SNOWFALL FROM THE NORTHWEST MOUNTAINS TODAY. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
5 winter storm. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2010Every state in 2010This day in weather historyWarnings in Wyoming, March 2010
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: 215041, 215043, 215044, 215045, 215042.