Alert archive / Arizona / Severe Thunderstorm Warnings in 2001
Severe Thunderstorm Warning 40, NWS Tucson, AZ
NWS Tucson, AZ issued this severe thunderstorm warning at Aug 15, 2001, 5:18 PM MST for Pima County, Santa Cruz County, Arizona. It was in force for 27 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
- Aug 15, 2001, 5:18 PM MST (00:18 UTC)
- Expired
- Aug 15, 2001, 5:45 PM MST
- In force
- 27 min
- Issued by
- NWS Tucson, AZ
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
Counties Pima County, AZ, Santa Cruz County, AZ
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 15, 5:30 PM MST | Thunderstorm Wind | Green Vly, AZ |
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 00:00Z, 0.3 hours before the alert went out and 43 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
- 1307 J/kg
- Mixed-layer CIN
- -8 J/kg
- Mixed-layer LCL
- 2414 m above ground
- 0-6 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- -11 m²/s²
- 0-3 km storm-relative helicity
- 17 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
780 WUUS55 KTWC 160018 SVRTUS AZC019-023-160045- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE TUCSON AZ 518 PM MST WED AUG 15 2001 THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... EXTREME SOUTHEASTERN PIMA COUNTY IN ARIZONA THIS INCLUDES GREEN VALLEY EXTREME NORTH CENTRAL SANTA CRUZ COUNTY IN ARIZONA * UNTIL 545 PM MST * AT 504 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM ABOUT 5 MILES SOUTH OF GREEN VALLEY...MOVING SOUTHWEST AT 5 MPH. * THE SEVERE THUNDERSTORM WILL BE NEAR... NEAR ARIVACA JUNCTION AT 535 PM. HAIL...INTENSE RAIN AND DAMAGING WINDS ARE LIKELY WITH THIS STORM. TAKE COVER IN A SUBSTANTIAL SHELTER UNTIL THE STORM PASSES. LAT...LON 3181 11082 3193 11098 3177 11118 3162 11098 PYTLAK
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 Aug 15, 2:30 PM MST, 2 hours 48 minutes earlier.
Area forecast discussion, Aug 15, 2:30 PM MST, 2 hours 48 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 230 PM MST WED AUG 15 2001 .SYNOPSIS...HIGH PRESSURE WILL BUILD IN FROM THE WEST COAST THE REMAINDER OF THE WEEK. THE RESULTING FLOW WILL GENERALLY DIMINISH THUNDERSTORM COVERAGE...PARTICULARLY WEST OF TUCSON. BY EARLY NEXT WEEK...THE HIGH MOVES EAST OF ARIZONA AND THE FLOW BECOMES FAVORABLE FOR A RETURN TO NORMAL THUNDERSTORM ACTIVITY. .DISCUSSION...AS EXPECTED THE FLOW HAS BECOME NORTHEASTERLY WITH US ON THE EAST SIDE OF THE NOW DOMINANT WEST COAST RIDGE. WEAK DEFORMATION ZONE STRETCHING AND SETTLING INTO SOUTHEAST ARIZONA...BUT RAPIDLY BECOMING NEUTRAL. DRY AIR TRYING WRAP IN FROM THE NORTH AND NORTHEAST...BUT IT LOOKS LIKE WERE HOLDING ON TO MOISTURE ACROSS MOST OF THE AREA. 10 TO 15KT STEERING FLOW NICE FOR STORMS TO COME OFF TERRAIN (OUTFLOW FROM THE RIM?)...BUT EARLY AFTERNOON DEVELOPMENT IS BEHIND WHAT ONE MIGHT EXPECT WITH THE AMOUNT OF MOISTURE STILL AVAILABLE AND CAPE VALUES. EVEN SOUTHEAST ARIZONA SHOULD SEE SOME DRYING EFFECTS TOMORROW AS UPSTREAM DOESNT HAVE MUCH TO OFFER WHILE WERE ON THE WRONG SIDE OF THE RIDGE AXIS. WELL STILL SEE CONVECTION...BUT MORE EMPHASIS WILL BE PLACED ON MOUNTAIN DEVELOPMENT IN THE FORECAST...AND FLASH FLOODING CONCERNS WILL DIMINISH. SYNOPTIC FEATURES WILL ONCE AGAIN BE FAVORABLE FOR INCREASING COVERAGE OF THUNDERSTORMS BY EARLY NEXT WEEK. AT ANY RATE...NORTHWEST MEXICO WILL REMAIN ACTIVE...AND OUTFLOWS FROM COMPLEXES WILL COUNTER MUCH OF ANY ATTEMPTED DRYING TREND THIS FAR SOUTH. M .TWC...NONE.
In the hours before
Special weather statement, Aug 15, 11:30 AM MST, 5 hours 48 minutes before
AZZ019-029>035-150700- SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TUCSON AZ 1155 AM MST TUE AUG 14 2001 .SYNOPSIS...EXPECT A STRONG THUNDERSTORM DAY TODAY...FOLLOWED BY HIGH PRESSURE BUILDING IN FROM WEST TOMORROW. THE RESULTING FLOW WILL GENERALLY DIMINISH THUNDERSTORM COVERAGE...PARTICULARLY WEST OF TUCSON. BY EARLY NEXT WEEK...THE HIGH MOVES EAST OF ARIZONA AND THE FLOW BECOMES FAVORABLE FOR A RETURN TO NORMAL THUNDERSTORM ACTIVITY. .DISCUSSION...MODELS STILL SHOWING STRONG THUNDERSTORMS WILL DEVELOP TO THE NORTH AND MOVE SOUTH AND SOUTHWEST ACROSS THE AREA THIS AFTERNOON. LOTS OF MINOR ISSUES...FIRST IS HOW MUCH MOISTURE CAN WE HOLD ONTO TODAY. DRYING NOTED ON PRECIPITABLE WATER FIELDS IS DUE TO MID LEVEL MOISTURE BUT BELOW 5000 FEET THERE IS STILL PLENTY OF MOISTURE. THIS ACTUALLY PLAYS INTO INCREASED SEVERE THREAT SINCE DRY MID LEVELS WILL HAVE AN ACCELERATING EFFECT...IN THE VERTICAL..ON STORMS. MODELS ALSO SHOW SEVERAL DEGREES OF COOLING WHICH WILL MAKE ATMOSPHERE MORE UNSTABLE. OF MORE IMPORTANCE IS THAT WE ARE UNDER THE ANTICYCLONIC CURVATURE AT THE CIRRUS LEVEL THAT WILL MAKE IT A MORE FAVORABLE ENVIRONMENT FOR ORGANIZED THUNDERSTORMS AND NOT JUST THE RANDOM EVENT WE HAD LAST NIGHT. THIS SAME TYPE OF CURVATURE WAS EVIDENT IN THE STORMS WHICH AFFECTED PHX AND THE WESTERN DESERTS LAST NIGHT. STORM SPEED MAY BE 15 MPH WHICH USUALLY WOULD ELIMINATE FLASH FLOODING BUT STORMS MAY BE LARGE WHICH WILL EQUALLY OFFSET THE SPEED PROBLEM. SINCE THERE IS LESS MOISTURE TO THE NORTH STORMS MAY NOT BE IMPRESSIVE LOOKING UNTIL THEY GET FARTHER SOUTH SO INCREASED THREAT IS FROM TUCSON TO WILLCOX AND FARTHER SOUTH. STORM MOTION WILL BE TO THE SOUTH AND SOUTHWEST AT 15 MPH. HOLBROOK
Special weather statement, Aug 15, 11:55 AM MST, 5 hours 23 minutes before
AZZ019-029>035-160700- SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TUCSON AZ 1155 AM MST WED AUG 15 2001 .SYNOPSIS...EXPECT A STRONG THUNDERSTORM DAY TODAY...FOLLOWED BY HIGH PRESSURE BUILDING IN FROM WEST TOMORROW. THE RESULTING FLOW WILL GENERALLY DIMINISH THUNDERSTORM COVERAGE...PARTICULARLY WEST OF TUCSON. BY EARLY NEXT WEEK...THE HIGH MOVES EAST OF ARIZONA AND THE FLOW BECOMES FAVORABLE FOR A RETURN TO NORMAL THUNDERSTORM ACTIVITY. .DISCUSSION...MODELS STILL SHOWING STRONG THUNDERSTORMS WILL DEVELOP TO THE NORTH AND MOVE SOUTH AND SOUTHWEST ACROSS THE AREA THIS AFTERNOON. LOTS OF MINOR ISSUES...FIRST IS HOW MUCH MOISTURE CAN WE HOLD ONTO TODAY. DRYING NOTED ON PRECIPITABLE WATER FIELDS IS DUE TO MID LEVEL MOISTURE BUT BELOW 5000 FEET THERE IS STILL PLENTY OF MOISTURE. THIS ACTUALLY PLAYS INTO INCREASED SEVERE THREAT SINCE DRY MID LEVELS WILL HAVE AN ACCELERATING EFFECT...IN THE VERTICAL..ON STORMS. MODELS ALSO SHOW SEVERAL DEGREES OF COOLING WHICH WILL MAKE ATMOSPHERE MORE UNSTABLE. OF MORE IMPORTANCE IS THAT WE ARE UNDER THE ANTICYCLONIC CURVATURE AT THE CIRRUS LEVEL THAT WILL MAKE IT A MORE FAVORABLE ENVIRONMENT FOR ORGANIZED THUNDERSTORMS AND NOT JUST THE RANDOM EVENT WE HAD LAST NIGHT. THIS SAME TYPE OF CURVATURE WAS EVIDENT IN THE STORMS WHICH AFFECTED PHX AND THE WESTERN DESERTS LAST NIGHT. STORM SPEED MAY BE 15 MPH WHICH USUALLY WOULD ELIMINATE FLASH FLOODING BUT STORMS MAY BE LARGE WHICH WILL EQUALLY OFFSET THE SPEED PROBLEM. SINCE THERE IS LESS MOISTURE TO THE NORTH STORMS MAY NOT BE IMPRESSIVE LOOKING UNTIL THEY GET FARTHER SOUTH SO INCREASED THREAT IS FROM TUCSON TO WILLCOX AND FARTHER SOUTH. STORM MOTION WILL BE TO THE SOUTH AND SOUTHWEST AT 15 MPH. HOLBROOK
Special weather statement, Aug 15, 1:17 PM MST, 4 hours 1 minute before
AZZ019-029>035-160700- SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TUCSON AZ 1155 AM MST WED AUG 15 2001 .SYNOPSIS...EXPECT A STRONG THUNDERSTORM DAY TODAY...FOLLOWED BY HIGH PRESSURE BUILDING IN FROM WEST TOMORROW. THE RESULTING FLOW WILL GENERALLY DIMINISH THUNDERSTORM COVERAGE...PARTICULARLY WEST OF TUCSON. BY EARLY NEXT WEEK...THE HIGH MOVES EAST OF ARIZONA AND THE FLOW BECOMES FAVORABLE FOR A RETURN TO NORMAL THUNDERSTORM ACTIVITY. .DISCUSSION...MODELS STILL SHOWING STRONG THUNDERSTORMS WILL DEVELOP TO THE NORTH AND MOVE SOUTH AND SOUTHWEST ACROSS THE AREA THIS AFTERNOON. LOTS OF MINOR ISSUES...FIRST IS HOW MUCH MOISTURE CAN WE HOLD ONTO TODAY. DRYING NOTED ON PRECIPITABLE WATER FIELDS IS DUE TO MID LEVEL MOISTURE BUT BELOW 5000 FEET THERE IS STILL PLENTY OF MOISTURE. THIS ACTUALLY PLAYS INTO INCREASED SEVERE THREAT SINCE DRY MID LEVELS WILL HAVE AN ACCELERATING EFFECT...IN THE VERTICAL..ON STORMS. MODELS ALSO SHOW SEVERAL DEGREES OF COOLING WHICH WILL MAKE ATMOSPHERE MORE UNSTABLE. OF MORE IMPORTANCE IS THAT WE ARE UNDER THE ANTICYCLONIC CURVATURE AT THE CIRRUS LEVEL THAT WILL MAKE IT A MORE FAVORABLE ENVIRONMENT FOR ORGANIZED THUNDERSTORMS AND NOT JUST THE RANDOM EVENT WE HAD LAST NIGHT. THIS SAME TYPE OF CURVATURE WAS EVIDENT IN THE STORMS WHICH AFFECTED PHX AND THE WESTERN DESERTS LAST NIGHT. STORM SPEED MAY BE 15 MPH WHICH USUALLY WOULD ELIMINATE FLASH FLOODING BUT STORMS MAY BE LARGE WHICH WILL EQUALLY OFFSET THE SPEED PROBLEM. SINCE THERE IS LESS MOISTURE TO THE NORTH STORMS MAY NOT BE IMPRESSIVE LOOKING UNTIL THEY GET FARTHER SOUTH SO INCREASED THREAT IS FROM TUCSON TO WILLCOX AND FARTHER SOUTH. STORM MOTION WILL BE TO THE SOUTH AND SOUTHWEST AT 15 MPH. HOLBROOK
The office that day
Everything else NWS Tucson, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 15, 6:01 PM MST | Severe Thunderstorm Warning | TWC | Pima | 29 min |
| Aug 15, 7:20 PM MST | Severe Thunderstorm Warning | TWC | Pima | 40 min |
| Aug 16, 4:51 PM MST | Severe Thunderstorm Warning | TWC | Pima | 54 min |
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.