A winter storm brought heavy snow and strong winds to western Wyoming and the Big Horn Mountains in central Wyoming. Snowfall ranged from 1 to 2 feet in the mountains to 6 to 12 inches in the lower elevations.
Every event with a place to put it; 14 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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 winter storm brought heavy snow and strong winds to western Wyoming and the Big Horn Mountains in central Wyoming. Snowfall ranged from 1 to 2 feet in the mountains to 6 to 12 inches in the lower elevations. Also, a wind gust of 73 mph was reported on February 22 at the Pine Creek Ski Resort.
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 21, 2:57 PM MST, 3 hours 3 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 257 PM MST FRI FEB 21 2003 ...TONIGHT THROUGH MONDAY... COMPLICATED WEATHER PATTERN DEVELOPING OVER THE COWBOY STATE THIS WEEKEND WITH MOIST DYNAMIC NORTHWEST FLOW ALOFT AND IMPRESSIVE ARCTIC BOUNDARY SAGGING SOUTH OUT OF MONTANA ON SATURDAY. GENERALLY FOLLOWED ALONG THE LINES OF THE ETA/MSO-ETA. FIRST SHORTWAVE IS MOVING ACROSS THE STATE CURRENTLY AND HELPING TO KICK OFF SOME CONVECTIVE SNOW SHOWERS EAST OF THE DIVIDE WITH LIGHT SNOW CONTINUING IN THE WESTERN MOUNTAINS. NEXT SPEED MAX APPROACHES THE WEST AFTER 06Z WITH STRONG ASSOCIATED H7-H3 COUPLET AND THUS STRONG UPWARD OMEGA. THIS COUPLET TRACKS SOUTHEAST ACROSS THE STATE SATURDAY MORNING WITH A LIKELY SWATH OF SNOW SHOWERS AND ISOLATED THUNDER SNOW (LAPSE RATES IN EXCESS OF 8C/KM AND LIFTED INDICES AT OR BELOW ZERO). HEAVY MOUNTAIN SNOW SHOULD FALL IN THE WESTERN MOUNTAINS FROM LATER THIS EVENING THROUGH MOST LIKELY SATURDAY NIGHT. STRONG WEST WINDS WITH GUSTS UP TO 50 MPH WILL CAUSE BLIZZARD CONDITIONS AT TIMES OVER THE MOUNTAIN PASSES. WILL UPGRADE ENTIRE WATCH AREA TO A WARNING AND EXTEND THROUGH SATURDAY NIGHT AS SECOND STRONG SHORTWAVE DROPS DOWN FROM THE NORTHWEST WITH THE ARCTIC BOUNDARY. WILL ALSO INCLUDE THE WESTERN VALLEYS AS SEVERAL BURSTS OF HEAVY SNOW COULD EASILY ADD UP TO 6 INCHES BY THE TIME ALL IS SAID AND DONE. WILL ALSO HAVE TO ISSUE WINTER STORM WATCH ACROSS MUCH OF THE NORTH FOR SATURDAY THROUGH SUNDAY. FIRST GOOD SHOT OF DYNAMICS AND INITIAL FRONTAL SURGE WILL GIVE A SPURT OF HEAVY SNOW AND THEN NEXT MAJOR SURGE SATURDAY NIGHT SHOULD PROVIDE POSSIBILITY OF MORE EXTENDED HEAVY SNOW. HARD TO TELL YET ON REST OF AREA AS JUST ABOUT ANY COULD VERIFY HIGHLIGHTS BY THE TIME THIS STORM IS OVER SUNDAY NIGHT. FULL FORCE OF ARCTIC BOUNDARY SHOULD DROP SOUTH SATURDAY NIGHT WITH BITTER AIR BEHIND IT AS INDICATED BY LARGE SUB-ZERO READINGS ACROSS MOST OF SOUTHERN CANADA AND NORTHERN NORTH DAKOTA. FAVORABLE DYNAMICS ON TOP OF THIS SHOULD KEEP SNOW GOING IN MOST OF THE AREA...ESPECIALLY EAST OF THE DIVIDE. VERY COLD NIGHT SUNDAY NIGHT AS FULL FORCE OF COLD AIR MOVES IN ALONG WITH POSSIBLE CLEARING SKIES. NEXT DEVELOPING STORM SYSTEM AND RESIDUAL UPSLOPE MAY KEEP SOME SNOW GOING IN THE SOUTHWEST CORNER ON MONDAY. SKRBAC ...MONDAY NIGHT THROUGH FRIDAY... LATEST 12Z GFS SPINS OFF SHORTWAVE OFF OF CUTOFF SW LOW NEAR SFO TUESDAY MORNING WITH SHORTWAVE MOVING SLC-CYS TUESDAY NIGHT. OLD FRONTAL BOUNDARY REMAINS BACKED UP AGAINST THE DIVIDE WITH BEST MOISTURE SOUTH OF FRONT. WILL TARGET SCT POPS ACROSS SW MTN ZONES AND ALONG INTERSTATE 80 CORRIDOR TUESDAY/TUESDAY NIGHT. LAST NIGHTS GFS OPENS UP AND BRINGS MAIN LOW ACROSS AREA WEDNESDAY WITH COLD UNSTABLE TROUGHINESS REMAINING OVER AREA AFTERWARDS. AEM .RIW...WINTER STORM WARNING MUCH OF WESTERN WYOMING FOR TONIGHT THROUGH SATURDAY NIGHT...INCLUDING ZONES 1...2...12>15...23>25 WINTER STORM WATCH FOR SATURDAY THROUGH SUNDAY FOR PORTIONS OF NORTHERN WYOMING...INCLUDING ZONES 3 AND 8>11.
WYZ001>020-022>030-221204- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 505 AM MST FRI FEB 21 2003 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT A WINTER STORM WATCH IS IN EFFECT TONIGHT AND SATURDAY FOR THE MOUNTAINS OF WESTERN WYOMING. A STORM SYSTEM IS EXPECTED TO BRING MODERATE TO HEAVY SNOW LATER THIS EVENING AND SATURDAY TO WESTERN WYOMING. SNOW AMOUNTS OF 12 TO 18 INCHES ARE POSSIBLE IN THE MOUNTAINS WITH UP TO 6 INCHES IN THE WESTERN VALLEYS. WEST WINDS OF 20 TO 30 MPH WITH HIGHER GUSTS WILL PRODUCE CONSIDERABLE BLOWING AND DRIFTING SNOW ON PASSES AND OPEN AREAS. TRAVEL IS EXPECTED BECOME TREACHEROUS IN WESTERN WYOMING. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY A WINTER STORM WATCH IS IN EFFECT FOR TONIGHT AND SATURDAY. MODERATE TO HEAVY SNOW WILL TAPER TO LIGHT SNOW BY LATE SATURDAY CONTINUING UNTIL LATE SUNDAY NIGHT. SNOW IS EXPECTED EAST OF THE CONTINENTAL DIVIDE SATURDAY THROUGH SUNDAY NIGHT AS AN ARCTIC COLD FRONT MOVES IN FROM MONTANA. TEMPERATURES SUNDAY ARE EXPECTED ONLY TO BE IN THE SINGLE DIGITS TO LOWER TEENS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED IN WESTERN WYOMING TONIGHT AND SATURDAY. WCJIN-WYNW-WYNE-WYSW TWB
The national radar mosaic for the moment the first event began.
14 winter storm. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2003Every state in 2003This day in weather historyWarnings in Wyoming, February 2003
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: 5343247, 5343248, 5343249, 5343250, 5343251, 5343252, 5343253, 5343254, 5343255, 5343833, 5343834, 5343835, 5343836, 5343837.