Colorado, 2002

Flash Flood in Colorado, August 3, 2002

August 3, 2002 · NWS GJT · 1 event in 1 county or zone

Flooding and mudslides occurred in several drainages along County Road 501, on the west side of Vallecito Reservoir, and in the Vallecito community. Five to eight feet of debris covered roads in some locations and 2 to 3 feet of mud and debris flowed into and around several homes and businesses.

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
$400,000
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.

Flooding and mudslides occurred in several drainages along County Road 501, on the west side of Vallecito Reservoir, and in the Vallecito community. Five to eight feet of debris covered roads in some locations and 2 to 3 feet of mud and debris flowed into and around several homes and businesses. A car was pushed 35 feet down a road and into a tree.

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 Aug 3, 2:17 AM MST, 9 hours 33 minutes earlier.

Area forecast discussion, Aug 3, 2:17 AM MST, 9 hours 33 minutes before
WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
317 AM MDT SAT AUG 3 2002

FEW LIGHT SHOWERS HANGING ON EARLY THIS MORNING...MAINLY OVER THE
CENTRAL AND SOUTHWEST MOUNTAINS IN WESTERN COLORADO.  MANY LOCATIONS
RECEIVED SOME MUCH NEEDED RAINFALL OVER THE PAST 24 HOURS AND THIS
TREND WILL CONTINUE TODAY AS MOIST S-SW FLOW ALOFT CONTINUES OVER THE
FORECAST AREA. SFC DEW POINTS ARE NOW UP INTO THE 50S OVER MUCH OF
EASTERN UTAH AND WESTERN COLORADO. LACK OF SUN THE PAST TWO DAYS HAS
HELD DEEPER CONVECTION AT BAY...ALTHOUGH THE SHOWERS WEVE RECEIVED
HAVE BEEN NICE STEADY SOAKERS. WOULD LIKE THIS TO CONTINUE...
HOWEVER DRIER AIR IS ALREADY APPROACHING THE REGION FROM THE SW.

THE ATMOSPHERE WILL ACTUALLY BECOME MORE UNSTABLE WITH DRYING ALOFT
LATER THIS AFTERNOON AND CONTINUED MOIST LOW LEVELS.  SO DEEPER
CONVECTION A POSSIBILITY LATER THIS AFTERNOON...ESPECIALLY OVER
EASTERN UTAH. CLOUD SHIELD SHOULD HANG ON MOST OF THE DAY ACROSS
WESTERN COLORADO...SO SURFACE HEATING HERE WILL AGAIN BY HELD IN
CHECK WITH ANOTHER BELOW NORMAL DAY TEMPERATURE-WISE.  WEAK WAVES IN
THE FLOW ARE HARD TO PICK OUT...SO NO ONE THING TO LATCH ONTO TO
GENERATE WIDESPREAD PRECIP OVER THE AREA.  THE EXCEPTION IS OVER
WESTERN UTAH...WHERE A SLIGHTLY STRONGER WAVE NOTED IN WATER VAPOR
IMAGERY IS EXPECTED TO LIFT NE INTO NE UT/NW CO LATE THIS
MORNING/AFTERNOON. 00Z AVN/NGM MODELS ALSO SHOWING A WEAK 60KT JET AT
THE H3 LEVEL SETTING UP OVER NE UTAH THIS AFTERNOON/EVENING. RIGHT
ENTRANCE REGION TO THE JET WL BE IN THE VCNTY...AND THIS WILL ALSO
HELP TO ENHANCE LIFT LATER TODAY.

THE DRIER AIR WILL WORK ACROSS NW COLORADO TONIGHT...WITH DEEPER
MOISTURE PLUME BECOMING CONFINED TO SW AND CENTRAL COLORADO.  LESS
ACTIVITY ON SUNDAY FOR ALL BUT SW COLORADO...ALTHOUGH LOW LEVEL
MOISTURE WILL BE SLOW TO ERODE...SO ISOLATED CONVECTION WILL STILL
BE IN THE FORECAST FOR THE NORTHERN ZONES AND MUCH OF EASTERN UTAH.

BY MONDAY...MODELS STRENGTHEN THE RIDGE OVER THE CENTRAL PLAINS...
WITH A STRONG TROUGH SETTING UP OVER THE WEST COAST.  THIS WL
STRENGTHEN MONSOONAL FLOW ONCE AGAIN...WITH ANOTHER SURGE OF
MOISTURE WORKING BACK INTO THE NORTHERN ZONES. JC

(MON-FRI):  PERSISTENT PATTERN IN PLACE BY MON WITH UPPER LEVEL
TROUGH ALONG THE WEST COAST AND HIGH PRESSURE RIDGE OVER THE CENTRAL
PLAINS. WEST COAST TROUGH WEAKENS BY MIDWEEK AS BRITISH COLOMBIAN LOW
CENTER EJECTS NORTHEAST EARLY THU.  HOWEVER THE GENERAL PATTERN
REMAINS FAVORABLE FOR SOUTHERLY FLOW OVER EASTERN UTAH AND WESTERN
COLORADO. ANY EMBEDDED WAVES WILL ENHANCE ACTIVITY AND KEEP NOCTURNAL
SHOWERS/THUNDERSTORMS POSSIBLE.  SO WILL CONTINUE TO BROADBRUSH WITH
CHANCE MOUNTAINS AND SLIGHT CHANCE VALLEYS. FAR WESTERN EDGE OF
FORECAST AREA LOOKS TO BE THE DRIEST PORTION AT THIS TIME.  BUT IF
THE POSITION OF SOUTHERLY FETCH SHIFTS WESTWARD EVEN A LITTLE...ANY
MOISTURE DIFFERENCES WILL BE MINIMIZED. EH

.GJT...NONE.

The radar

The Grand Junction radar (KGJX), 200 km away, was scanning. The volume nearest the first event began at 18:48 UTC.

Open the radar archive at this moment

Event by event

1 flash flood. Local standard time, as filed.

Flash Flood, La Plata

When
August 3, 11:50 AM MST to 12:40 PM MST
Where
La Plata County, 16 mi NE of Durango
Property damage
$400,000
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 2002Every state in 2002This day in weather historyWarnings in Colorado, August 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: 5317976.