Alert archive / Arizona / Flash Flood Warnings in 2001
Flash Flood Warning 20, NWS Tucson, AZ
NWS Tucson, AZ issued this flash flood warning at Jul 31, 2001, 1:05 PM MST for Pima County, Arizona. It was in force for 24 hr. No storm report in the archive falls inside the area while it was in force.
The area
The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.
The facts
- Issued
- Jul 31, 2001, 1:05 PM MST (20:05 UTC)
- Expired
- Aug 1, 2001, 12:35 PM MST
- In force
- 24 hr
- Issued by
- NWS Tucson, AZ
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
County Pima County, AZ
The radar
The Tucson radar (KEMX), 41 km from the middle of the area, began a volume at 20:06 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.
The nearest sounding before it
Tuscon, AZ (KTUS), launched 12:00Z, 8.1 hours before the alert went out and 2 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
- 473 J/kg
- Mixed-layer CIN
- -80 J/kg
- Mixed-layer LCL
- 1545 m above ground
- 0-6 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- -6 m²/s²
- 0-3 km storm-relative helicity
- 64 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 WGUS55 KTWC 312003 FFWTUS AZC019-312035- BULLETIN - EAS ACTIVATION REQUESTED FLASH FLOOD WARNING NATIONAL WEATHER SERVICE TUCSON AZ 105 PM MST TUE JUL 31 2001 THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A * FLASH FLOOD WARNING FOR... NORTHEASTERN PIMA COUNTY IN ARIZONA THIS INCLUDES...CATALINA...ORO VALLEY...TUCSON * UNTIL 135 PM MST * AT 105 PM MST...WEATHER SERVICE DOPPLER RADAR INDICATED VERY HEAVY RAIN HAD FALLEN ACROSS THE EASTERN PIMA COUNTY AND THE CITY OF TUCSON. THE STRONGEST STORMS WERE MOVING THROUGH THE NORTHWEST PORTION OF TUCSON. THE HEAVY RAINFALL WILL CONTINUE TO FLOOD WASHES...STREAMS AND CITY STREETS THROUGH 130 PM MST. THE STORMS WERE MOVING NORTHWEST AT 15 MPH. RAIN GAGES ON THE SOUTHEAST SIDE OF TUCSON HAVE SHOWN RAINFALL RATES OF HALF OF AN INCH IN 30 MINUTES...WITH STORM TOTAL PRECIPITATION OF 1 TO 2 INCHES. A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING. DO NOT ATTEMPT TO CROSS SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY AUTOMOBILE. LAT...LON 3193 11121 3194 11049 3252 11050 3251 11120 ZELL
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 Jul 31, 8:45 AM MST, 4 hours 20 minutes earlier.
Area forecast discussion, Jul 31, 8:45 AM MST, 4 hours 20 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 845 AM MST TUE JUL 31 2001 SYNOPSIS...HIGH PRESSURE FROM NEW MEXICO TO THE SOUTHERN PLAINS WILL REMAIN STATIONARY WHILE A WEAK TROUGH REMAINS ON THE WEST COAST. PLENTY OF MOISTURE REMAINS IN SOUTHEAST ARIZONA AND THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER THE AREA TODAY...WITH MORE SHOWERS AND THUNDERSTORMS AGAIN WEDNESDAY. DISCUSSION...SATELLITE PICS SHOWING GENERALLY PARTLY CLOUDY SKIES ACROSS THE CWA ATTM...WITH A LITTLE MORE WIDESPREAD CLOUDINESS OVER THE PHOENIX AREA AND PORTIONS OF COCHISE COUNTY. ALREADY SEEING STORM DEVELOPMENT OVER EXTREME SOUTHEAST COCHISE COUNTY...OUT AHEAD OF STRONG EASTERLY WAVE SOUTH OF THE TEXAS BIG BEND. THIS AREA OF MODERATE TO STRONG STORMS (ALREADY!!!) IS IN AREA OF UPPER DIVERGENCE AHEAD OF THE EASTERLY WAVE. WITH DEVELOPMENT OCCURRING THIS EARLY...THIS TELLS ME THAT THERE IS GOOD DYNAMICS WITH THIS SYSTEM...SINCE IT'S TO EARLY FOR THE STORMS TO BE FEEDING OFF OF DAYTIME HEATING. WITH ALMOST NO DEVELOPMENT ACROSS THE CWA YESTERDAY...THERE WILL BE PLENTY OF CAPE TO WORK WITH. 12Z TUS SOUNDING AND GOES TOTAL PRECIPITABLE WATER IMAGERY BOTH INDICATE PLENTY OF MOISTURE ACROSS SOUTHEAST ARIZONA...WITH VALUES IN THE 1.2 TO 2.0 INCH CATEGORY. SOME DRYING IS NOTED OVER FAR WESTERN ARIZONA AND IN THE WHITE MOUNTAINS...HOWEVER SOUTH TO SOUTHEAST FLOW AHEAD OF EASTERLY WAVE SHOULD MOISTEN WHITES BACK UP TODAY. FORECAST LOOKS ON TRACK WITH STORMS DEVELOPING IN COCHISE AND SANTA CRUZ COUNTIES EARLY...SPREADING INTO THE REST OF THE CWA BY THIS AFTERNOON. NO UPDATES TO CURRENT FORECAST PACKAGE AT THIS TIME. ZELL .TWC...NONE.
In the hours before
Special weather statement, Jul 31, 11:01 AM MST, 2 hours 4 minutes before
AZZ019-029>035-010700- SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TUCSON AZ 1200 PM MST TUE JUL 31 2001 .SYNOPSIS...ABUNDANT MOISTURE IN COMBINATION WITH A STRONG UPPER LEVEL SYSTEM OVER NORTHERN MEXICO WILL PROVIDE A NEAR CLIMATOLOGICAL THREAT OF FLASH FLOODING ACROSS THE REGION. THE THREAT FOR SEVERE THUNDERSTORMS IS LOW ALTHOUGH BRIEF WIND GUSTS AND SMALL HAIL MAY ACCOMPANY THE STRONGER STORMS. .DISCUSSION...A DEEP INVERTED TROUGH MOVING TO THE WEST OVER NORTHERN MEXICO WILL PROVIDE THE LIFT NECESSARY FOR THUNDERSTORM DEVELOPMENT ACROSS SOUTHEAST ARIZONA THIS AFTERNOON AND TONIGHT. 12Z TUS SOUNDING AND GOES TOTAL PRECIPITABLE WATER IMAGERY INDICATE PLENTY OF MOISTURE ACROSS SOUTHEAST ARIZONA...WITH VALUES IN THE 1.2 TO 2.0 INCH CATEGORY. SOME DRYING IS NOTED OVER FAR WESTERN ARIZONA AND ACROSS THE WHITE MOUNTAINS. HOWEVER INCREASING SOUTHEAST FLOW AHEAD OF THE INVERTED TROUGH SHOULD INCREASE MOISTURE OVER THE WHITES TODAY. THE THREAT FOR SEVERE THUNDERSTORMS IS LOW...ALTHOUGH BRIEF WIND GUSTS IN EXCESS OF 40 MPH AND SMALL HAIL MAY OCCUR WITH THE STRONGER STORMS. THE FLASH FLOOD THREAT WILL BE NEAR CLIMATOLOGY ACROSS THE ENTIRE OUTLOOK AREA DUE TO THE AMPLE MOISTURE AND WIDESPREAD COVERAGE OF STORMS. STORM MOVEMENT WILL BE TO THE NORTHWEST AT 15 MPH.
Special weather statement, Jul 31, 12:00 PM MST, 1 hour 5 minutes before
AZZ019-029>035-010700- SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TUCSON AZ 1200 PM MST TUE JUL 31 2001 .SYNOPSIS...ABUNDANT MOISTURE IN COMBINATION WITH A STRONG UPPER LEVEL SYSTEM OVER NORTHERN MEXICO WILL PROVIDE A NEAR CLIMATOLOGICAL THREAT OF FLASH FLOODING ACROSS THE REGION. THE THREAT FOR SEVERE THUNDERSTORMS IS LOW ALTHOUGH BRIEF WIND GUSTS AND SMALL HAIL MAY ACCOMPANY THE STRONGER STORMS. .DISCUSSION...A DEEP INVERTED TROUGH MOVING TO THE WEST OVER NORTHERN MEXICO WILL PROVIDE THE LIFT NECESSARY FOR THUNDERSTORM DEVELOPMENT ACROSS SOUTHEAST ARIZONA THIS AFTERNOON AND TONIGHT. 12Z TUS SOUNDING AND GOES TOTAL PRECIPITABLE WATER IMAGERY INDICATE PLENTY OF MOISTURE ACROSS SOUTHEAST ARIZONA...WITH VALUES IN THE 1.2 TO 2.0 INCH CATEGORY. SOME DRYING IS NOTED OVER FAR WESTERN ARIZONA AND ACROSS THE WHITE MOUNTAINS. HOWEVER INCREASING SOUTHEAST FLOW AHEAD OF THE INVERTED TROUGH SHOULD INCREASE MOISTURE OVER THE WHITES TODAY. THE THREAT FOR SEVERE THUNDERSTORMS IS LOW...ALTHOUGH BRIEF WIND GUSTS IN EXCESS OF 40 MPH AND SMALL HAIL MAY OCCUR WITH THE STRONGER STORMS. THE FLASH FLOOD THREAT WILL BE NEAR CLIMATOLOGY ACROSS THE ENTIRE OUTLOOK AREA DUE TO THE AMPLE MOISTURE AND WIDESPREAD COVERAGE OF STORMS. STORM MOVEMENT WILL BE TO THE NORTHWEST AT 15 MPH.
The office that day
Everything else NWS Tucson, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 31, 12:05 PM MST | Flash Flood Warning | TWC | Pima | |
| Jul 31, 12:20 PM MST | Severe Thunderstorm Warning | TWC | Pima | 40 min |
| Jul 31, 1:25 PM MST | Flash Flood Warning | TWC | Pima | 5 min |
| Jul 31, 1:40 PM MST | Flash Flood Warning | TWC | Pinal |
Nearby
Flash Flood Warnings in Arizona, 2001Every flash flood warning in 2001
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.