Alert archive / Arizona / Severe Thunderstorm Warnings in 2001
Severe Thunderstorm Warning 24, NWS Tucson, AZ
NWS Tucson, AZ issued this severe thunderstorm warning at Jul 31, 2001, 12:20 PM MST for Pima County, Arizona. It was in force for 40 min. 1 report came from 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, with what was reported inside it.
The facts
- Issued
- Jul 31, 2001, 12:20 PM MST (19:20 UTC)
- Expired
- Jul 31, 2001, 1:00 PM MST
- In force
- 40 min
- 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), 46 km from the middle of the area, began a volume at 19:21 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 31, 12:30 PM MST | Thunderstorm Wind 50 M | Tucson, AZ | At 1230 MST, pima county dispatch reported a 8 inch diamter tree blown down in a residental area. A spotter reported a measured wind gust of 58 mph at 1240 MST. |
NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.
The nearest sounding before it
Tuscon, AZ (KTUS), launched 12:00Z, 7.3 hours before the alert went out and 6 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 WUUS55 KTWC 311918 SVRTUS AZC019-312000- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE TUCSON AZ 1220 PM MST TUE JUL 31 2001 THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... NORTHEASTERN PIMA COUNTY IN ARIZONA THIS INCLUDES...CATALINA...ORO VALLEY...TUCSON * UNTIL 100 PM MST * AT 1220 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM OVER TUCSON...OR ABOUT 5 MILES SOUTHEAST OF TUCSON...MOVING NORTHWEST AT 15 MPH. REMEMBER...A SEVERE THUNDERSTORM CAN PRODUCE LARGE HAIL...DAMAGING WINDS IN EXCESS OF 58 MPH...DEADLY LIGHTNING...AND HEAVY RAIN. LAT...LON 3196 11104 3215 11050 3253 11075 3249 11133
What forecasters said that day
The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at Jul 31, 8:45 AM MST, 3 hours 35 minutes earlier.
Area forecast discussion, Jul 31, 8:45 AM MST, 3 hours 35 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, 1 hour 19 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, 20 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, 1:05 PM MST | Flash Flood Warning | TWC | Pima | 24 hr |
| 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
Severe Thunderstorm Warnings in Arizona, 2001Every severe thunderstorm 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.