3 high wind, as filed by the National Weather Service.
Every event with a place to put it; 3 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 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 Apr 30, 1:03 PM MST, 10 hours 58 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 203 PM MDT MON APR 30 2001 WV/IR SAT IMAGERY SHOWING UPPER TROF OFF THE NORTHERN BC COAST WITH A POWERFUL JET STREAMING INTO THE NORTHERN INTERMOUNTAIN WEST. A SHORTWAVE FORMED EARLIER THAT WASNT INDICATED BY YESTERDAYS MODEL RUNS. AS A RESULT OF THE THIS SHORTWAVE...THE JET WILL BE NUDGED A FURTHER SOUTH BRINGING A BIT OF ENERGY INTO NORTHERN MOUNTAINS. SO EXPECT SOME LIGHT SNOW TO BEGIN LATER THIS EVENING...MAYBE UP TO 3 INCHES IN YNP. A SURFACE FRONT DROPS INTO NORTHERN WYOMING AFT 12Z/01 AND WILL LIKELY BE HELD UP BY STRONG SOUTHWEST GRADIENT OVER NORTHERN BIG HORN BASIN AND JOHNSON COUNTY. EXPECT THE FRONT TO OVERPOWER THE GRADIENT AS THE SUN LOWERS ALLOWING IT TO CONTINUE ITS SOUTHWARD PUSH IN THE EVENING. NOT MUCH MOISTURE WITH THIS SO DONT EXPECT MUCH MORE THAN ISOLATED TO SCATTERED RAIN OR SNOW SHOWERS WITH FRONT. UPSLOPE FLOW FORMS BEHIND THE FRONT WEDNESDAY MORNING WITH SURFACE LOW SETTING UP OVER NORTHERN NEW MEXICO. SO FRONT RANGE OF COLORADO LOOKING MORE FAVORABLE FOR PRECIP. MESOETA INDICATING THICKNESSES AS LOW AS 534 OVER NORTHERN WYOMING WEDNESDAY MORNING SO EXPECT ANY PRECIP TO BE SNOW. AS MAIN TROF PASSES TO OUR NORTH...A CUT OFF LOW FORMS OVER COLORADO ON WEDNESDAY AND GETS WOUND UP WEDNESDAY EVENING ENHANCING UPSLOPE FLOW AND RH FIELD OVER WYOMING. SO EXPECT LIGHT PRECIP TO FORM FROM SOUTH TO NORTH THURSDAY MORNING AND THROUGHOUT THE DAY THURSDAY. DAYTIME THICKNESSES FROM AVN ARE IN THE MID TO UPPER 540S...THIS WOULD INDICATE MAINLY RAIN AT LOWER ELEVATIONS BUT SNOW CANT BE RULED OUT THIS EARLY. IN THE EXTENDED AVN AND MRF KEEP THE UPSLOPE FLOW THROUGH SATURDAY MORNING...THEN SLOWLY LIFTS THE STORM OUT INTO THE PLAINS. MODERATING TEMPS THEN TAKES PLACE WITH A RIDGE BUILDING INTO THE WEST BY MONDAY...CANT RULE OUT SHOWERS AS WYOMING UNDER NW FLOW. .RIW...NONE. TWB
The national radar mosaic for the moment the first event began.
3 high wind. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2001Every state in 2001This day in weather historyWarnings in Wyoming, May 2001
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: 5244935, 5244933, 5244934.