Alert archive / Arizona / Flash Flood Warnings in 2002
Flash Flood Warning 30, NWS Tucson, AZ
NWS Tucson, AZ issued this flash flood warning at Aug 20, 2002, 4:45 PM MST for Cochise County, Arizona. It was in force for 90 min. 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, 4:45 PM MST (23:45 UTC)
- Expired
- Aug 20, 2002, 6:15 PM MST
- In force
- 90 min
- Issued by
- NWS Tucson, AZ
- Area
- Counties, with a storm outline in the text
County Cochise County, AZ
The radar
The Tucson radar (KEMX), 46 km from the middle of the area, began a volume at 23:46 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
Tuscon, AZ (KTUS), launched 12:00Z, 11.8 hours before the alert went out and 77 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
- 1300 J/kg
- Mixed-layer CIN
- -39 J/kg
- Mixed-layer LCL
- 1365 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 62 m²/s²
- 0-3 km storm-relative helicity
- 62 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.8
The text
As transmitted, in the capitals the NWS used until 2016.
000 WGUS55 KTWC 202345 FFWTWC AZC003-210115- BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE TUCSON AZ 442 PM MST TUE AUG 20 2002 THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A * FLASH FLOOD WARNING FOR... WEST CENTRAL COCHISE COUNTY IN ARIZONA * UNTIL 615 PM MST * AT 436 PM MST...WEATHER SERVICE DOPPLER RADAR INDICATED VERY HEAVY RAIN OVER WEST CENTRAL COCHISE COUNTY...OR ABOUT 5 MILES EAST OF SAINT DAVID. SMALL STREAMS AND NORMALLY DRY WASHES WILL FLOOD QUICKLY. DO NOT DRIVE INTO FLOODED AREAS...ESPECIALLY THROUGH ROADWAY DIPS ALONG HORSE RANCH ROAD EAST OF SAINT DAVID. THE ROAD AHEAD MAY BE UNDERMINED OR WASHED AWAY. ABANDON VEHICLES CAUGHT IN RISING WATER IMMEDIATELY. LAT...LON 3194 11024 3178 11011 3193 11001 3202 11010
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 Tucson, AZ wrote its last area forecast discussion before this flash flood warning went out at Aug 20, 1:50 PM MST, 2 hours 55 minutes earlier.
Area forecast discussion, Aug 20, 1:50 PM MST, 2 hours 55 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 150 PM MST TUE AUG 20 2002 .SYNOPSIS...A LOW PRESSURE SYSTEM WILL STRENGTHEN OVER THE WESTERN UNITED STATES WEDNESDAY INTO EARLY NEXT WEEK. THIS WILL RESULT IN A DRIER SOUTHWESTERLY FLOW ALOFT THAT WILL LEAD TO A DECREASE IN THUNDERSTORM ACTIVITY THE NEXT SEVERAL DAYS. ALONG WITH THIS DRYING TREND...DAYTIME TEMPERATURES WILL BE ON THE INCREASE AS HIGH PRESSURE BECOMES CENTERED OVER NORTHERN MEXICO. .DISCUSSION...A DRYING AND WARMING TREND WILL BE THE MAIN WEATHER STORY THE REST OF THIS WEEK. A LOW PRESSURE SYSTEM IS FORECAST TO DEEPEN AND DROP SOUTH INTO NORTHERN CALIFORNIA BY THE WEEKEND. AS A RESULT...A SOUTHWESTERLY FLOW ALOFT IS FORECAST TO STRENGTHEN OVER THE REGION BRINGING DRIER AIR INTO THE STATE. THIS DRYING WILL LEAD TO A DECREASE IN THUNDERSTORM ACTIVITY WEDNESDAY INTO THE WEEKEND. MEDIUM RANGE MODELS INDICATE THIS WILL BE A SIGNIFICANT DRYING TREND THAT COULD LEAD TO A LONG STRETCH OF LITTLE OR NO THUNDERSTORM ACTIVITY...AT LEAST THROUGH NEXT WEEK. ALONG WITH THE DRYING... DAYTIME TEMPERATURES WILL BE ON THE INCREASE AS HIGH PRESSURE ALOFT BECOMES CENTERED OVER NORTHERN MEXICO AND BAJA. IN THE MEANTIME...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUED TO DEVELOP THIS AFTERNOON GENERALLY EAST OF TUCSON. THE DRY POCKET OF AIR ALOFT OVER THE WEST CENTRAL AND SOUTHWEST DESERTS THIS MORNING HAD PROGRESSED A LITTLE FARTHER EAST THAN PREVIOUSLY EXPECTED. BEST UPPER DYNAMICS ASSOCIATED WITH THE WEAK UPPER LOW EXITING THE NORTHERN GULF OF CALIFORNIA WERE MAINLY OVER NORTHERN AND EASTERN ARIZONA. THUS...PRESENT THINKING IS THAT FAST MOVING T-STORMS WILL CONTINUE TO DEVELOP INTO THE EARLY EVENING HOURS EAST OF TUCSON ACROSS COCHISE...GRAHAM...GREENLEE COUNTIES WITH AREAS WEST OF TUCSON REMAINING IN THE CLEAR. .TWC...NONE.
In the hours before
Special weather statement, Aug 20, 11:58 AM MST, 4 hours 47 minutes before
AZZ019-029>035-210700- SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TUCSON AZ 1158 AM MST TUE AUG 20 2002 .SYNOPSIS...EXPECT UPPER LEVEL DYNAMIC FORCING TO AID THUNDERSTORM DEVELOPMENT ACROSS ALL OF SOUTHEAST ARIZONA TODAY. THE PRESENCE OF DEEP LOW TO MID-LEVEL MOISTURE TO THE EAST OF TUCSON WILL INCREASE THE PROBABILITY OF HEAVY PRECIPITATION TO VALUES SLIGHTLY ABOVE CLIMATOLOGY. HOWEVER...DRIER AIR FURTHER WEST WILL DECREASE THE THREAT OF HEAVY PRECIPITATION...BUT WILL INCREASE THE PROBABILITY OF DAMAGING THUNDERSTORM WINDS. .DISCUSSION...AN UPPER LEVEL LOW CENTERED OVER THE NORTHERN GULF OF CALIFORNIA WILL CONTINUE TO LIFT NORTHEAST THROUGH SOUTHEAST ARIZONA THIS AFTERNOON AND EVENING...RESULTING IN LARGE SCALE DYNAMIC FORCING ACROSS THE AREA AND AIDING CONVECTIVE INITIATION. TO THE EAST OF TUCSON...A SIGNIFICANT AMOUNT OF MID LEVEL DEBRIS CLOUDINESS THIS MORNING HAS SLOWED SOLAR HEATING. ALTHOUGH THIS WOULD NORMALLY DELAY THUNDERSTORM DEVELOPMENT UNTIL THE LATE AFTERNOON...UPPER LEVEL DYNAMIC FORCING WILL BE STRONG ENOUGH TO OVERCOME THIS LACK OF HEATING. THE WATER VAPOR SATELLITE IMAGERY INDICATED A MID TO UPPER-LEVEL MOISTURE DISCONTINUITY LINE STRETCHING ALONG THE WESTERN FRINGES OF COCHISE AND GRAHAM COUNTIES. EXPECT THUNDERSTORM TO FIRE ALONG THIS DEMARCATION LINE THIS AFTERNOON AS IT CONTINUES TO PUSH EAST. IN ADDITION...PRECIPITABLE WATER IMAGERY INDICATED THAT DEEPER LOW TO MID-LEVEL MOISTURE RESIDES EAST OF TUCSON. THIS WILL INCREASE THE PROBABILITY OF HEAVY PRECIPITATION ACROSS THE EASTERN COUNTIES. HOWEVER...A STRONG NORTHEAST STEERING FLOW AT 15 MPH WILL LIMIT THE TIME THAT THESE THUNDERSTORMS HAVE TO DROP PRECIPITATION IN ANY GIVEN LOCATION. THEREFORE...THE PROBABILITY FOR RECEIVING PRECIPITATION IN EXCESS OF ONE INCH WILL BE ONLY BY SLIGHTLY HIGHER THAN CLIMATOLOGY TO THE EAST. DRIER AIR TO THE WEST OF TUCSON SUGGESTS A GREATER RISK OF DAMAGING THUNDERSTORM WINDS ACROSS PORTIONS OF CENTRAL AND WESTERN PIMA COUNTY. THEREFORE...THE PROBABILITY FOR A SEVERE THUNDERSTORM WILL INCREASE TOWARDS THE WEST. SINCE EASTERN PIMA AND SANTA CRUZ COUNTY LIE IN BETWEEN THE DRIER AIR TO THE WEST AND THE MOIST AIR TO THE EAST...THESE AREAS WILL BE FAVORABLE FOR BOTH STRONG THUNDERSTORM WINDS AND LOCALLY HEAVY RAINFALL.
Special weather statement, Aug 20, 12:12 PM MST, 4 hours 33 minutes before
AZZ019-029>035-210700- SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK...CORRECTION NATIONAL WEATHER SERVICE TUCSON AZ 1212 AM MST TUE AUG 20 2002 .SYNOPSIS...EXPECT UPPER LEVEL DYNAMIC FORCING TO AID THUNDERSTORM DEVELOPMENT ACROSS ALL OF SOUTHEAST ARIZONA TODAY. THE PRESENCE OF DEEP LOW TO MID-LEVEL MOISTURE TO THE EAST OF TUCSON WILL INCREASE THE PROBABILITY OF HEAVY PRECIPITATION TO VALUES SLIGHTLY ABOVE CLIMATOLOGY. HOWEVER...DRIER AIR FURTHER WEST WILL DECREASE THE THREAT OF HEAVY PRECIPITATION...BUT WILL INCREASE THE PROBABILITY OF DAMAGING THUNDERSTORM WINDS. .DISCUSSION...AN UPPER LEVEL LOW CENTERED OVER THE NORTHERN GULF OF CALIFORNIA WILL CONTINUE TO LIFT NORTHEAST THROUGH SOUTHEAST ARIZONA THIS AFTERNOON AND EVENING...RESULTING IN LARGE SCALE DYNAMIC FORCING ACROSS THE AREA AND AIDING CONVECTIVE INITIATION. TO THE EAST OF TUCSON...A SIGNIFICANT AMOUNT OF MID LEVEL DEBRIS CLOUDINESS THIS MORNING HAS SLOWED SOLAR HEATING. ALTHOUGH THIS WOULD NORMALLY DELAY THUNDERSTORM DEVELOPMENT UNTIL THE LATE AFTERNOON...UPPER LEVEL DYNAMIC FORCING WILL BE STRONG ENOUGH TO OVERCOME THIS LACK OF HEATING. THE WATER VAPOR SATELLITE IMAGERY INDICATED A MID TO UPPER-LEVEL MOISTURE/DENSITY DISCONTINUITY LINE STRETCHING ALONG THE WESTERN FRINGES OF COCHISE AND GRAHAM COUNTIES. LOOK FOR THUNDERSTORM TO FIRE ALONG THIS DEMARCATION LINE THIS AFTERNOON AS IT CONTINUES TO PUSH EAST. PRECIPITABLE WATER IMAGERY INDICATED THAT THE DEEPER LOW TO MID LEVEL MOISTURE RESIDES EAST OF TUCSON. ALTHOUGH THIS WILL INCREASE THE PROBABILITY OF RECEIVING PRECIPITATION IN EXCESS OF ONE INCH ACROSS THE EASTERN COUNTIES...A STRONGER STORM MOTION...TOWARDS THE NORTHEAST AT 15 MPH...WILL LIMIT THE TIME THAT THESE THUNDERSTORMS HAVE TO DROP PRECIPITATION IN ANY GIVEN LOCATION. THEREFORE...THE PROBABILITY FOR RECEIVING PRECIPITATION IN EXCESS OF ONE INCH WILL BE ONLY BY SLIGHTLY HIGHER THAN CLIMATOLOGY. DRIER AIR TO THE WEST OF TUCSON SUGGESTS A GREATER RISK OF DAMAGING THUNDERSTORM WINDS ACROSS PORTIONS OF CENTRAL AND WESTERN PIMA COUNTY. THEREFORE...THE PROBABILITY FOR A SEVERE THUNDERSTORM WILL INCREASE TOWARDS THE WEST. SINCE EASTERN PIMA AND SANTA CRUZ COUNTY LIE IN BETWEEN THE DRIER AIR TO THE WEST AND THE MOIST AIR TO THE EAST...THESE AREAS WILL BE FAVORABLE FOR BOTH STRONG THUNDERSTORM WINDS AND LOCALLY HEAVY RAINFALL. WWUS85 KTWC 201912 CCA SPSTWC AZZ019-029>035-210700- SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK...CORRECTION NATIONAL WEATHER SERVICE TUCSON AZ 1212 PM MST TUE AUG 20 2002 .SYNOPSIS...EXPECT UPPER LEVEL DYNAMIC FORCING TO AID THUNDERSTORM DEVELOPMENT ACROSS ALL OF SOUTHEAST ARIZONA TODAY. THE PRESENCE OF DEEP LOW TO MID-LEVEL MOISTURE TO THE EAST OF TUCSON WILL INCREASE THE PROBABILITY OF HEAVY PRECIPITATION TO VALUES SLIGHTLY ABOVE CLIMATOLOGY. HOWEVER...DRIER AIR FURTHER WEST WILL DECREASE THE THREAT OF HEAVY PRECIPITATION...BUT WILL INCREASE THE PROBABILITY OF DAMAGING THUNDERSTORM WINDS. .DISCUSSION...AN UPPER LEVEL LOW CENTERED OVER THE NORTHERN GULF OF CALIFORNIA WILL CONTINUE TO LIFT NORTHEAST THROUGH SOUTHEAST ARIZONA THIS AFTERNOON AND EVENING...RESULTING IN LARGE SCALE DYNAMIC FORCING ACROSS THE AREA AND AIDING CONVECTIVE INITIATION. TO THE EAST OF TUCSON...A SIGNIFICANT AMOUNT OF MID LEVEL DEBRIS CLOUDINESS THIS MORNING HAS SLOWED SOLAR HEATING. ALTHOUGH THIS WOULD NORMALLY DELAY THUNDERSTORM DEVELOPMENT UNTIL THE LATE AFTERNOON...UPPER LEVEL DYNAMIC FORCING WILL BE STRONG ENOUGH TO OVERCOME THIS LACK OF HEATING. THE WATER VAPOR SATELLITE IMAGERY INDICATED A MID TO UPPER-LEVEL MOISTURE/DENSITY DISCONTINUITY LINE STRETCHING ALONG THE WESTERN FRINGES OF COCHISE AND GRAHAM COUNTIES. LOOK FOR THUNDERSTORM TO FIRE ALONG THIS DEMARCATION LINE THIS AFTERNOON AS IT CONTINUES TO PUSH EAST. PRECIPITABLE WATER IMAGERY INDICATED THAT THE DEEPER LOW TO MID LEVEL MOISTURE RESIDES EAST OF TUCSON. ALTHOUGH THIS WILL INCREASE THE PROBABILITY OF RECEIVING PRECIPITATION IN EXCESS OF ONE INCH ACROSS THE EASTERN COUNTIES...A STRONGER STORM MOTION...TOWARDS THE NORTHEAST AT 15 MPH...WILL LIMIT THE TIME THAT THESE THUNDERSTORMS HAVE TO DROP PRECIPITATION IN ANY GIVEN LOCATION. THEREFORE...THE PROBABILITY FOR RECEIVING PRECIPITATION IN EXCESS OF ONE INCH WILL BE ONLY BY SLIGHTLY HIGHER THAN CLIMATOLOGY. DRIER AIR TO THE WEST OF TUCSON SUGGESTS A GREATER RISK OF DAMAGING THUNDERSTORM WINDS ACROSS PORTIONS OF CENTRAL AND WESTERN PIMA COUNTY. THEREFORE...THE PROBABILITY FOR A SEVERE THUNDERSTORM WILL INCREASE TOWARDS THE WEST. SINCE EASTERN PIMA AND SANTA CRUZ COUNTY LIE IN BETWEEN THE DRIER AIR TO THE WEST AND THE MOIST AIR TO THE EAST...THESE AREAS WILL BE FAVORABLE FOR BOTH STRONG THUNDERSTORM WINDS AND LOCALLY HEAVY RAINFALL.
The office that day
Everything else NWS Tucson, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 4:42 PM MST | Flash Flood Warning | TWC | Cochise | 33 min |
Nearby
Flash Flood Warnings in Arizona, 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.