Alert archive / Arizona / Severe Thunderstorm Warnings in 2001
Severe Thunderstorm Warning 48, NWS Tucson, AZ
NWS Tucson, AZ issued this severe thunderstorm warning at Aug 17, 2001, 5:20 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
- Aug 17, 2001, 5:20 PM MST (00:20 UTC)
- Expired
- Aug 17, 2001, 6:00 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
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 17, 5:20 PM MST | Thunderstorm Wind 52 M | Oro 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 30 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
- 501 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 2875 m above ground
- 0-6 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- -1 m²/s²
- 0-3 km storm-relative helicity
- 43 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
502 WUUS55 KTWC 180021 SVRTUS AZC019-180100- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE TUCSON AZ 520 PM MST FRI AUG 17 2001 THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... NORTHEASTERN PIMA COUNTY IN ARIZONA THIS INCLUDES...CATALINA...ORO VALLEY * UNTIL 600 PM MST * AT 512 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM OVER CATALINA...MOVING SOUTHWEST AT 15 MPH. REMEMBER...A SEVERE THUNDERSTORM CAN PRODUCE LARGE HAIL...DAMAGING WINDS IN EXCESS OF 60 MPH...DEADLY LIGHTNING...AND HEAVY RAIN. LAT...LON 3249 11099 3250 11073 3229 11099 3241 11114
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 17, 2:10 PM MST, 3 hours 10 minutes earlier.
Area forecast discussion, Aug 17, 2:10 PM MST, 3 hours 10 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 210 PM MST FRI AUG 17 2001 .SYNOPSIS...HIGH PRESSURE OVER NORTHWEST ARIZONA WILL GRADUALLY SHIFT INTO NEW MEXICO THROUGH SUNDAY. MEANWHILE...AN UPPER LEVEL LOW PRESSURE AREA OVER BAJA WILL GRADUALLY MOVE WEST INTO THE PACIFIC. ALTHOUGH STORM COVERAGE THROUGH SUNDAY WILL BE SOMEWHAT LIMITED AND FAVOR THE EVENING HOURS...THEY COULD BE ON THE STRONG SIDE. BY SUNDAY...THE PATTERN WILL FAVOR MORE TYPICAL AFTERNOON AND EVENING THUNDERSTORMS...WHICH WILL CONTINUE INTO THE END OF THE WEEK. .DISCUSSION...TSTMS ALREADY FIRING IN THE WHITES AND SE COCHISE COUNTY. ANVIL DRIFT CONTINUES TO SHOW DIFFLUENCE ALOFT, WITH THE DIFFUENCE AXIS EXTENDING FROM NE SONORA INTO PINAL COUNTY. LAPS DATA SHOWS CONVECTIVE INHIBITION PRETTY MUCH GONE OVER THE E AND WEAKENING RAPIDLY IN THE W. THIS SUPPORTS THE 18Z ETA WHICH COMPLETELY RELOADS OUR BOUNDARY LAYER BY 00Z. I DONT SEE ANY DISTINCT FOCUSING MECHANISM OTHER THAN OUTFLOWS AND IMPRESSIVE UPPER DIVERGENCE, SO WELL HOLD COVERAGE NEAR CLIMO (LOW-MID SCATTERED) WHILE USING HEIGHTENED WORDING. SWODY1 OUTLOOK LOOKS VERY GOOD. 0-6KM SHEAR IS PROGGED TO BE AS HIGH AS 40KTS TONIGHT (IT WAS AROUND 30KTS ON THE 12Z SOUNDING) WHICH MEANS ANY STORMS THAT GET SOME DEPTH WILL TRY TO ORGANIZE INTO SMALL LINES OR BOW SEGMENTS. AT LEAST THAT WILL KEEP THE RISK OF HEAVY RAIN ON THE LOW SIDE. GOES-10 RAPID SCAN UPDATE WILL RUN FROM 22Z-07Z TONIGHT. UPPER HIGH IS CONTINUING TO BRIDGE TO OUR N, AND ONCE THE PLAINS TROUGH LIFTS OUT, IT WILL REFORM OVER THE 4-CORNERS. MODELS INSIST ON RAMPING PRECIP WATERS ABOVE 1.5 BY SUN NIGHT AND TURNING OUR 30KT E FLOW AT 500MB TO 15KT SE. THAT WILL SHIFT US BACK INTO GREATER COVERAGE/HEAVY RAINER MODE IN THE EXTENDED. FORECASTS HAVE BEEN ADVERTISING THIS TREND ALL WEEK, AND I SEE LITTLE REASON TO DEVIATE. ID GO A LITTLE HIGHER WITH POPS SUN, BUT MODELS SUGGEST ANOTHER BIG NIGHT SAT NIGHT, AND WITH THE FLOW WEAKENING ON SUN, WE MAY HAVE A HARDER TIME RELOADING THE DESERTS AND VALLEYS. WELL HAVE TO WATCH THE DAY 6-7 AS MRF CONTINUES TO DROP A TROUGH DOWN THE WEST COAST. THERES ISNT STRONG TELECONNECTIVE SUPPORT FOR SUCH AN AMPLIFIED TROUGH, AND EVEN IF IT HAPPENS, WED PROBABLY TAKE A COUPLE OF DAYS TO DRY DOWN. FOR NOW, IM INCLINED TO LET THE CURRENT EXTENDED RIDE. PYTLAK .TWC...NONE.
In the hours before
Special weather statement, Aug 17, 11:57 AM MST, 5 hours 23 minutes before
AZZ019-029>035-180700- SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TUCSON AZ 12 NOON MST FRI AUG 17 2001 .SYNOPSIS...SOUTHEAST ARIZONA WILL REMAIN WEDGED BETWEEN AN UPPER LEVEL LOW OVER BAJA AND HIGH PRESSURE OVER NORTHERN ARIZONA. THIS HAS BEEN A FAVORED AREA FOR STRONG THUNDERSTORM DEVELOPMENT ALL WEEK...AND MAY ONCE AGAIN LEAD TO SIGNIFICANT DEVELOPMENT LATE THIS AFTERNOON AND ESPECIALLY TONIGHT. .DISCUSSION...MOST OF SOUTHEAST ARIZONA RECEIVED THUNDERSTORMS THURSDAY EVENING. NORMALLY...THIS WOULD LEAD TO A DECREASE ON BOTH STORM COVERAGE AND STRENGTH TODAY. IN FACT...THE MORNING SOUNDINGS ACROSS ARIZONA REFLECTED A STABILIZED ATMOSPHERE. HOWEVER...THE EAST WIND FLOW TODAY REMAINS RATHER STRONG...ESPECIALLY IN THE MID LEVELS. THIS IS IMPORTING ADDITIONAL MOISTURE FROM SOUTHWEST NEW MEXICO AND WILL CAUSE THE ATMOSPHERE TO DESTABILIZE FAIRLY RAPIDLY LATER THIS AFTERNOON. ISOLATED THUNDERSTORMS WERE ALREADY DEVELOPING OVER THE WHITE MOUNTAINS. THAT AREA WAS SPARED FROM THE STRONGER STORMS YESTERDAY. ALTHOUGH IT WILL TAKE SEVERAL MORE HOURS FOR THE VALLEYS TO RECOVER...ABOVE NORMAL AFTERNOON TEMPERATURES...BELOW NORMAL TEMPERATURES ABOVE 15000 FEET...RATHER STRONG STEERING WINDS...AND THE PRESENCE OF DIVERGENCE ALOFT ALL SUGGEST ANOTHER ACTIVE LATE AFTERNOON AND EVENING. VALLEY DEVELOPMENT WILL NOT OCCUR UNTIL LATE IN THE AFTERNOON OR THIS EVENING...BUT SOME OF THE STORMS COULD LAST WELL PAST MIDNIGHT...ESPECIALLY OVER THE WESTERN DESERTS. LIKE THE PAST COUPLE OF DAYS...STORM COVERAGE WILL NOT BE AS GREAT AS USUAL FOR MID AUGUST BECAUSE PRECIPITABLE WATERS ARE A BIT LOW. HOWEVER... ANY STORMS THAT DEVELOP WILL BE ABLE TO FORM INTO SHORT LINES OR BOW SEGMENTS WHICH WOULD BE CAPABLE OF DAMAGING WINDS. THE MID LEVEL TEMPERATURES ARE ALSO COLD ENOUGH TO SUPPORT HAIL UP TO AROUND AN INCH IN DIAMETER. THE RISK OF FLASH FLOODING IS BELOW CLIMATOLOGY BECAUSE OF THE RAPID STORM MOTIONS WHICH ARE EXPECTED. STORM MOVEMENT WILL BE GENERALLY SOUTHWEST AT 20 TO 25 MPH. PYTLAK
The office that day
Everything else NWS Tucson, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 17, 5:44 PM MST | Severe Thunderstorm Warning | TWC | Pima | 61 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.