Flash Flood in Wyoming, July 9, 2001

Name: Flash Flood in Wyoming, July 9, 2001
Start: 2001-07-09T13:30
End: 2001-07-09T13:30
Location: Wyoming

July 9, 2001 · NWS RIW · 1 event in 1 county or zone

Flash flooding along Green Creek on the north fork of the Shoshone River. Eyewitnesses reported a 3 foot wall of mud and water.

Where it happened

Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
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The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 1

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.

What happened

The episode as NWS RIW wrote it up.

Flash flooding along Green Creek on the north fork of the Shoshone River. Eyewitnesses reported a 3 foot wall of mud and water.

What forecasters said that day

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 Jul 9, 1:30 PM MST, 0 minutes earlier.

Area forecast discussion, Jul 9, 1:30 PM MST, 0 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
230 PM MDT MON JUL 9 2001

SUNSHINE HAS HELPED DESTABLIZE AIRMASS THIS PM. WV SATL LOOP SHOWS A
FEW FEATURES MOVG THRU FLOW. ONE IS PUSHING INTO UT AND HEADED FOR ID
LTR TDY WITH ANOTHER IMPULSE MOVG FM NRN MEXICO TWD SE AZ. FCST PROB
WL BE POPS TNGT. FAR W AND N SEEM TO BE IN THE BEST AREAS FOR POPS AS
WV ROTATES THRU. CENT AND SOUTH CWA WL HAVE LESS CHC AS THIS AREA IN
THE SUBSIDENCE AREA BEHIND WV. WL MONITR CONVCTN TRENDS AND ADJUST
BFR ZONES DEPART. MILD LOWS AND GUID CLOSE. ON TUE WV MOVES INTO MT
WITH 700MB FLO PROGD TO WSW WHILE 500MB STAYS SW. THE WV THAT MOVS
THRU AZ TNGT MAY BE A PLAYER FOR THE FAR W TUE PM CONVCTN AS IT MOVS
THRU THE FLO. WL KEEP HIR POPS FAR W AND N ONCE AGN WITH LOWER POPS
CENT CWA. THEN THE WEAK TROF PASSES THRU WY TUE NT AND WED WITH SOME
DRYING PROGD IN THE WEST WED PM WITH AMPLE MSTR CENT/E FOR SCT POPS.
HIGH TEMPS TUE AND WED DEPENDENT ON CLD CVR AND WL ADJUST GUID BASED
ON THAT. IN EXTNDD EC/MRF START TO SHIFT UPR HI CNTR WEST PLACING
CNTR ARND NE NM/TX PNHNDLE 12Z FRI. SOME DIFF IN EC/MRF BY 12Z SAT AS
EC MOVS HI CNTR TO NR FOUR CRNRS WITH MRF KEEPING IT IN NEW MEX.
WHILE ALL THIS GOES ON A SERIES OF SHTWVS MOV THRU THE SW FLOW THRU
FRI. FAIRLY MOIST THU/FRI FOR SOME POPS EACH DAY. THINGS SEEM TO DRY
OUT SAT-MON AS FLO BCMS MORE WSW. WL PLAY DRIER SCENARIO THEN. TEMPS
ABT THE SAME THRU FRI THEN SLGTLmY WRMR SAT-MON.

.RIW...NONE

AR

The radar

The Billings radar (KBLX), 167 km away, was scanning. The volume nearest the first event began at 20:28 UTC.

Open the radar archive at this moment

Event by event

1 flash flood. Local standard time, as filed.

Flash Flood, Park

When: July 9, 1:30 PM MST
Where: Park County, 23 mi W of Cody
Reported by: NEWSPAPER
Coordinates: 44.521, -109.588 (the zone’s center; the record gives no point)

What these are

Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Wyoming in 2001 Every state in 2001 This day in weather history Warnings in Wyoming, July 2001

Sources

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: 5258151.