Alert archive / Colorado / Flash Flood Warnings in 2002
Flash Flood Warning 35, NWS Grand Junction, CO
NWS Grand Junction, CO issued this flash flood warning at Aug 20, 2002, 9:16 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 20, 2002, 9:16 PM MDT (03:16 UTC)
- Expired
- Aug 21, 2002, 12:15 AM 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
The radar
The Grand Junction radar (KGJX), 188 km from the middle of the area, began a volume at 03:19 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
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 00:00Z, 3.3 hours before the alert went out and 202 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
- 413 J/kg
- Mixed-layer CIN
- -107 J/kg
- Mixed-layer LCL
- 1704 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- -39 m²/s²
- 0-3 km storm-relative helicity
- 25 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.4
The text
As transmitted, in the capitals the NWS used until 2016.
000 WGUS55 KGJT 210316 FFWGJT COC067-210615- BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE GRAND JUNCTION CO 914 PM MDT TUE AUG 20 2002 THE NATIONAL WEATHER SERVICE IN GRAND JUNCTION HAS ISSUED A * FLASH FLOOD WARNING FOR... NORTHEASTERN LA PLATA COUNTY IN SOUTHWEST COLORADO * UNTIL 1215 AM MDT * AT 913 PM MDT...WEATHER SERVICE DOPPLER RADAR INDICATED HEAVY RAIN 6 MILES SOUTHEAST OF TACOMA...OR ABOUT 12 MILES NORTHEAST OF DURANGO. * HEAVY RAIN OVER THE MISSIONARY RIDGE BURN AREA WILL CAUSE DEBRIS AND MUD FLOWS. DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY. MOVE TO HIGHER GROUND. 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 3735 10791 3723 10762 3751 10747 3762 10776
1 follow-up statement
061 RWUS32 KGJT 210433 FFSGJT COC067-210615- FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE GRAND JUNCTION CO 1030 PM MDT TUE AUG 20 2002 ...FLASH FLOOD WARNING FOR NORTHEAST LA PLATA COUNTY CONTINUES UNTIL 1215 AM WEDNESDAY MORNING... RAIN SHOWERS OVER THE MISSIONARY RIDGE BURN SITE ARE DECREASING. ADDITIONAL HEAVY RAIN WILL NO LONGER BE EXPECTED TONIGHT...WITH LIGHT SHOWERS COMING TO AN END BY MIDNIGHT. RAINFALL ESTIMATES FROM REMOTE SENSORS INDICATE THAT A QUARTER TO A HALF INCH OF RAIN HAS FALLEN IN THE MISSIONARY RIDGE BURN AREA. THIS IS SUFFICIENT RAINFALL TO BREAK DEBRIS DAMS AND CAUSE AN INCREASE OF MUD FLOWS AND FLASH FLOODING. COUNTRY ROADS AND FARMLANDS NEAR CREEKS AND STREAMS AND OTHER LOW LYING AREAS ARE SUBJECT TO FLOODING. DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY. MOVE TO HIGHER GROUND. $$ FRISBIE
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 20, 2:34 PM MDT, 6 hours 42 minutes earlier.
Area forecast discussion, Aug 20, 2:34 PM MDT, 6 hours 42 minutes before
WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 234 PM MDT TUE AUG 20 2002 BROAD TROUGH OF LOW PRESSURE SETTING UP OVER THE PACIFIC NORTHWEST HAS PLACED EASTERN UTAH AND WESTERN COLORADO UNDER THE INFLUENCE OF MOIST SW FLOW TODAY (MORNING KGJT SOUNDING SHOWED PRECIPITABLE WATER IN EXCESS OF 1.2 INCHES). SCATTERED SHOWERS AND THUNDERSTORMS WILL LIKELY LINGER INTO THE LATE NIGHT HOURS AS A COUPLE MORE WEAK SHRTWVS MOVE THROUGH THE AREA. WL CONT THE FLASH FLOOD WATCH FOR LA PLATA AND GARFIELD COUNTIES IN WESTERN COLORADO DUE TO THE RAINFALL EARLIER TODAY...WITH MORE SHOWERS AND THUNDERSTORMS STILL A GOOD POSSIBILITY. OVERALL TREND IN THE NEW MODELS RUNS CONTS TO ADVERTISE DRIER AIR SWEEPING THROUGH THE AREA BY LATE TONIGHT AND DURING THE DAY ON WEDNESDAY. HOWEVER...LOW LEVEL MOISTURE WILL BE SLOWER TO ERODE... AND WARMER AFTERNOON TEMPS WL STILL LEAD TO THE POSSIBILITY OF ADDITIONAL SHOWERS AND THUNDERSTORMS BY THE AFTERNOON HOURS. MAIN FOCUS OF CONVECTION THOUGH IS EXPECTED TO BE CONFINED TO THE HIGHER TERRAIN AND OVER THE SOUTHERN VALLEYS...CLOSER TO THE DEEPER MOISTURE. SIMILAR TRENDS WL CONT ON THURSDAY WITH TEMPS SLOWLY CREEPING BACK UP TO ABOVE NORMAL READINGS BY THE END OF THE WEEK. JDC (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 21, 1:23 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; radar from the NEXRAD Level II archive.