Name: Flash Flood in Colorado, September 11, 2002
Start: 2002-09-11T01:40
End: 2002-09-11T12:00
Location: Colorado

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

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The toll

Deaths: 0
Injuries: 0
Property damage: $100,000
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 GJT wrote it up.

A persistent rainfall resulted in 6 to 10 feet of mud and debris flows across sections of County Road 250. Many other county roads in the Missionary Ridge burn area were also closed due to debris and mud flows. Additional damage occurred to personal property.

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 Grand Junction, CO wrote its last area forecast discussion before the first event at Sep 11, 1:33 AM MST, 7 minutes earlier.

Area forecast discussion, Sep 11, 1:33 AM MST, 7 minutes before

WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
233 AM MDT WED SEP 11 2002

SHORTWAVE TROUGH LIFTING NORTH ACROSS THE LOWER COLORADO RIVER IS
TAKING ON A BIT OF A NEGATIVE TILT PER WATER VAPOR IMAGERY. DIFFLUENT
FLOW ALOFT AND UPPER JET ARCHING ACROSS THE FOUR CORNERS HELPING
SUPPORT PRECIPITATION AHEAD OF THE TROUGH AXIS. 88D SHOWING AREAS OF
LIGHT RAIN WITH EMBEDDED MODERATE SHOWERS MAINLY FROM MONTROSE COUNTY
SOUTH AND ACROSS SAN JUAN COUNTY IN SOUTHEAST UTAH. HOURLY RAINFALL
RATES GENERALLY LESS THAN A TENTH OF AN INCH EXCEPT IN FAVORED
UPSLOPE AREAS WHERE SOME RATES NEAR TWO TENTHS HAVE BEEN RECORDED.
PRECIPITATION WILL GRADUALLY EXPAND NORTH THROUGH THE MORNING AS THE
FORECAST AREA REMAINS UNDER SYNOPTIC SCALE LIFT. GREATEST QPF AGAIN
IS PROGGED ACROSS THE FOUR CORNERS AREA WHERE OROGRAPHICS LIFT WILL
PLAY A ROLE. POTENTIAL FOR HEAVY RAIN EXISTS AGAIN WITH AMOUNTS IN
EXCESS OF ONE INCH POSSIBLE TODAY ACROSS THE SAN JUANS AND AREAS TO
THE SOUTH. HEAVIEST RAIN LIKELY TO OCCUR THIS AFTERNOON WHEN THE
PRECIPITATION BECOMES MORE CONVECTIVE IN NATURE.

THE UPPER LOW IS FORECAST TO LIFT NORTH INTO UTAH TONIGHT AND THEN
MOVE EAST ALONG THE COLORADO AND WYOMING BORDER THURSDAY AND THURSDAY
NIGHT. IN RESPONSE...OUR MOIST SOUTHERLY FLOW WILL VEER TO THE WEST
AND SET THE STAGE FOR A DRYING TREND THE END OF THE WEEK. COOLER H5
TEMPS THURSDAY SHOULD PROVIDE A LITTLE BETTER CHANCE FOR
THUNDERSTORMS ACROSS THE AREA. CLOUDY AND MOIST REGIME WILL KEEP
TEMPS BELOW NORMAL TODAY AND THURSDAY. LINDQUIST

EXTENDED (FRI-TUE)...MEDIUM RANGE MODELS INDICATE AN EMBEDDED OPEN
WAVE AND ASSOCIATED TROF WILL MOVE EASTWARD THROUGH THE WEST COAST
RIDGE ON FRI AND EARLY SAT. SUFFICIENT MOISTURE AND DYNAMICS WILL
ALLOW FOR A CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS. AS THE
TROF PASSES ON SATURDAY, THE FLOW ALOFT WILL BECOME NORTHWEST AND
CONSIDERABLY DRIER. A LARGE RIDGE OF HIGH PRESSURE WILL THEN
DOMINATE MOST OF THE WESTERN U.S. THROUGH THE BEGINNING OF THE WORK
WEEK. BY TUE ANOTHER EMBEDDED TROF IS FORECAST TO MOVE INTO THE
RIDGE OVER THE WEST COAST...BUT LOOKS TO DAMPEN OUT AS IT MOVES
INTO THE GREAT BASIN AREA BY WED. CURRENT PACKAGE COVERS ALL OF
THIS, SO NO BIG CHANGES TO THE EXTENDED. BA

.GJT...FLASH FLOOD WATCH THROUGH 10 PM MDT FOR SOUTHWEST COLORADO
       AND SOUTHEAST UTAH.

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

1 flash flood. Local standard time, as filed.

Flash Flood, La Plata

When: September 11, 1:40 AM MST to 12:00 PM MST
Where: La Plata County, 5 mi N of Durango
Property damage: $100,000
Reported by: EMERGENCY MANAGER
Coordinates: 37.287, -107.843 (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

More

Every storm in Colorado in 2002 Every state in 2002 This day in weather history Warnings in Colorado, September 2002

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: 5320916.