Flash Flood in Wyoming, September 14, 2001

Name: Flash Flood in Wyoming, September 14, 2001
Start: 2001-09-14T14:30
End: 2001-09-14T14:30
Location: Wyoming

September 14, 2001 · NWS RIW · 1 event in 1 county or zone

Nursing home ceiling collapsed due to the weight of the accumulated hail and rain.

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
Other

Open the live radar over this ground

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.

Nursing home ceiling collapsed due to the weight of the accumulated hail and rain.

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 Sep 14, 2:00 PM MST, 30 minutes earlier.

Area forecast discussion, Sep 14, 2:00 PM MST, 30 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
300 PM MDT FRI SEP 14 2001

CANADIAN COLD FRONT THROUGH FORECAST AREA EAST OF DIVIDE AND GOING
THROUGH SW THROUGH SOUTH PASS ACROSS SWEETWATER COUNTY WITH
WIDESPREAD CLOUD COVER AND LIGHT PRECIPITATION BEHIND FRONT...ALONG
WITH EMBEDDED THUNDERSTORMS FIRING OFF OF HIGHER TERRAIN AND MOVING
THROUGH BASIN.  COLDER TEMPERATURES WITH STRONGER FRONT AND MORE
WIDESPREAD PRECIPITATION THAN PREVIOUS FORECAST.  EXPECT UPPER SHORT
WAVE TROUGH EXTENDING SW FROM UPPER LOW CENTER OVER E MT TO E CNTRL
ID TO PASS THROUGH FORECAST AREA WITH WEAK RIDGING ALOFT OVER AREA BY
MID MORNING SAT ENDING WIDESPREAD PRECIPITATION EVENT AROUND NOON.
EXPECT WEAK RIDGE TO KEEP IT DRY WITH COLDER NIGHTS AND WARMER DAYS
SAT NIGHT THROUGH SUN NIGHT THEN BRING IN NEXT UPPER LEVEL SHORT WAVE
TROUGH AND PACIFIC FRONT MONDAY FOLLOWED BY CANADIAN FRONT MONDAY
NIGHT AND TUESDAY.  MRF SHOWING MILD AND DRY PERIOD WED THROUGH FRI
IN EXTENDED AND CAN SEE NO REASON DEVIATE.  WILL MENTION SNOW
ACCUMULATIONS OF 2 TO 4 INCHES IN MOUNTAINS EAST OF DIVIDE ABOVE 9000
TONIGHT.

.RIW...NONE

C.BAKER

The radar

The Riverton/Lander radar (KRIW), 13 km away, was scanning. The volume nearest the first event began at 21:29 UTC.

Open the radar archive at this moment

Event by event

1 flash flood. Local standard time, as filed.

Flash Flood, Fremont

When: September 14, 2:30 PM MST
Where: Fremont County, Lander
Reported by: LAW ENFORCEMENT
Coordinates: 43.041, -108.630 (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, September 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: 5269629.