Alert archive / Colorado / Flash Flood Warnings in 2002
Flash Flood Warning 36, NWS Grand Junction, CO
NWS Grand Junction, CO issued this flash flood warning at Aug 21, 2002, 1:23 PM MDT for La Plata County, Colorado. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Aug 21, 2002, 1:23 PM MDT (19:23 UTC)
- Expired
- Aug 21, 2002, 4:20 PM MDT
- In force
- 3 hr
- Issued by
- NWS Grand Junction, CO
- Area
- Counties, with a storm outline in the text
County La Plata County, CO
Did it verify
Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The nearest sounding before it
Grand Junction, CO (KGJT), launched 12:00Z, 7.4 hours before the alert went out and 198 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 340 J/kg
- Mixed-layer CIN
- -85 J/kg
- Mixed-layer LCL
- 1574 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 67 m²/s²
- 0-3 km storm-relative helicity
- 100 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted, in the capitals the NWS used until 2016.
000 WGUS55 KGJT 211923 FFWGJT COC067-212220- BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE GRAND JUNCTION CO 120 PM MDT WED AUG 21 2002 THE NATIONAL WEATHER SERVICE IN GRAND JUNCTION HAS ISSUED A * FLASH FLOOD WARNING FOR... NORTHEASTERN LA PLATA COUNTY IN SOUTHWEST COLORADO * UNTIL 420 PM MDT * AT 115 PM MDT...LAW ENFORCEMENT OFFICIALS REPORTED DEBRIS SLIDES ALONG JACKS CREEK NEAR VALLECITO RESERVOIR. THE THUNDERSTORMS THAT HAVE CAUSED THESE SLIDES ARE MOVING VERY SLOWLY TO THE NORTHEAST AND WILL CONTINUE THIS AFTERNOON. * THE THUNDERSTORMS WITH EXCESSIVE RAINFALL WILL BE NEAR... RURAL NORTHEASTERN LA PLATA COUNTY AT 130 PM MDT HEAVY RAIN OVER THE MISSIONARY RIDGE BURN AREA WILL CAUSE ADDITIONAL DEBRIS AND MUD FLOWS. A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING. IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY. RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY AUTOMOBILE. IF YOUR VEHICLE STALLS, ABANDON IT IMMEDIATELY AND SEEK HIGHER GROUND. TO REPORT SEVERE WEATHER HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN GRAND JUNCTION. LAT...LON 3738 10786 3733 10750 3763 10748 3763 10766 $$ AVERY
1 follow-up statement
000 RWUS32 KGJT 212203 FFSGJT COC067-212220- FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE GRAND JUNCTION CO 400 PM MDT WED AUG 21 2002 ...FLASH FLOOD WARNING FOR NORTHEAST LA PLATA COUNTY HAS BEEN CANCELLED... RAIN SHOWERS HAVE MOVED OUT OF NORTHEAST LA PLATA COUNTY. THE THREAT OF FLASH FLOODING FOR THE MISSIONARY RIDGE BURN AREA HAS COME TO AN END. DRIER AIR IS MOVING ACROSS LA PLATA COUNTY AND CHANCES OF HEAVY SHOWERS HAVE DIMINISHED. THEREFORE...THE FLASH FLOOD WARNING FOR NORTHEAST LA PLATA COUNTY HAS BEEN CANCELLED. THERE STILL IS A CHANCE OF THUNDERSTORM ACTIVITY LATER THIS EVENING. THE FLASH FLOOD WATCH CONTINUES UNTIL 1000 PM. $$
What forecasters said that day
The local office's own words before this flash flood warning went out, 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 this flash flood warning went out at Aug 21, 3:08 AM MDT, 10 hours 15 minutes earlier.
Area forecast discussion, Aug 21, 3:08 AM MDT, 10 hours 15 minutes before
WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 308 AM MDT WED AUG 21 2002 DRIER CONDITIONS EXPECTED THE NEXT SEVERAL DAYS. A TROUGH WILL REMAIN CUTOFF FROM THE MAIN FLOW AND WILL SIT OVER THE PACNW AND NRN GREAT BASIN WITH HIGH PRESSURE OVER NMEX AND THE BIG BEND AREA THROUGH FRIDAY NIGHT. ERN UT/WRN CO WILL BE UNDER A MODERATE WSW WIND BAND THAT WILL ALLOW BREEZY CONDITIONS TO DEVELOP EACH AFTERNOON...AND MODERATING TEMPERATURES. THOUGH TDAS HIGH TEMPS WILL BE SIGNIFICANTLY HIGHER THAN YESTERDAYS...MAX TEMPS SHOULD NOT CHANGE MUCH IN DAY 2 AND 3. TWO SHORTWAVES EJECTING FROM THE WRN LOW WILL MOVE NE OF THE CWA BEFORE SUNRISE. SUBIDENCE AND DRYING WILL FALL THROUGH THE MORNING. ANOTHER LITTLE VORT MAX AND MINOR JET SPEED MAXIMA IS EVIDENT ON WV IMAGERY OVER SRN CA AND SHOULD ROTATE NE AND OVER THE SRN PART OF THE CWA THIS AFTERNOON. WILL KEEP CURRENT FORECAST AS IS WITH WDLY SCT TO SCT TSTMS THIS AFTERNOON ASSCTD WITH THIS WAVE AND AFTERNOON HEATING. THUR AND FRI SHOULD SEE ONLY DIURNAL TERRAIN-FOCUSED CONVECTION. CJC (SAT-TUE)...MOSTLY DRY. UPPER LOW LINGERING NEAR OR/CA/NV POINT EXPECTED TO TO LIFT OUT DURING THE WEEKEND AS UPPER HIGH BUILDS WEST ACROSS DESERT SOUTHWEST. DRIER SOUTHWEST FLOW SAT-SUN AS MOISTURE APPEARS LIMITED BELOW 500 MB. HOWEVER...POSSIBLE WEAK JET SUPPORT ASSOCIATED WITH EJECTING UPPER LOW PLUS DAYTIME HEATING AND ANY WEAK IMPULSES ENOUGH TO KEEP MENTION OF SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS FOR THE MTNS SAT-SUN. ECWMF THEN KEEPS A TROUGH NEAR PAC NW COAST EARLY NEXT WEEK WHILE AVN HAS REMNANTS OF UPPER LOW OVER THE NORTHERN ROCKIES WITH WEAK TROUGHING FROM WY BACK TO SRN CA. WILL KEEP A SLIGHT CHANCE OF THUNDERSTORMS FOR THE MTNS MON-TUE. LITTLE CHANGE IN TEMPS. JAD .GJT...NONE.
The office that day
Everything else NWS Grand Junction, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 6:28 PM MDT | Severe Thunderstorm Warning | GJT | San Miguel | 47 min |
| Aug 20, 7:07 PM MDT | Severe Thunderstorm Warning | GJT | Montrose, San Miguel | 38 min |
| Aug 20, 9:06 PM MDT | Severe Thunderstorm Warning | GJT | Mesa | 24 min |
| Aug 20, 9:16 PM MDT | Flash Flood Warning | GJT | La Plata | 3 hr |
Nearby
Flash Flood Warnings in Colorado, 2002Every flash flood warning in 2002
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.