Alert archive / Arizona / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 99, NWS Tucson, AZ

September 7, 1997Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Sep 7, 1997, 5:31 PM MST for Pima County, Arizona. It was in force for 29 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Sep 7, 1997, 5:31 PM MST (00:31 UTC)
Expired: Sep 7, 1997, 6:00 PM MST
In force: 29 min
Issued by: NWS Tucson, AZ
Area: Whole counties

County Pima County, AZ

The nearest sounding before it

Tuscon, AZ (KTUS), launched 00:00Z, 0.5 hours before the alert went out and 84 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 957 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 2606 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 0 m²/s²
0-3 km storm-relative helicity: 106 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

227 
WUUS1 KTUS 080032 RRA
SVRTUS
AZC019-080100-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
531 PM MST SUN SEP 7 1997

THE NATIONAL WEATHER SERVICE IN TUCSON AZ HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 600 PM MST
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN SOUTHERN ARIZONA

   ...SOUTH CENTRAL PIMA COUNTY
 
AT 527 PM MST...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 4
MILES NORTHEAST OF SASABE MOVING WEST NORTHWEST AT 15 MPH.
THIS STORM WILL MOVE ACROSS HIGHWAY 286 BY 540 PM. THIS STORM WAS
CAPABLE OF PRODUCING WIND GUSTS IN EXCESS OF 60 MPH...BRIEF HEAVY
RAIN...AND FREQUENT LIGHTNING.

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 Sep 7, 2:35 PM MST, 2 hours 56 minutes earlier.

Area forecast discussion, Sep 7, 2:35 PM MST, 2 hours 56 minutes before

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST SUN SEP 7 1997

STORMS FIRING ON MTNS NOW...A LITTLE LATER THAN SAT...ISOLD AND
SMALL. AND AS ALWAYS THE QUESTION IS WHETHER THEY WILL GET OFF
MTNS AND INTO VALLEY. TEMPS ARE RUNNING 2 TO 3C HIGHER TODAY IN
VALLEYS AND STILL MAY SEE 1 OR 2C MORE BEFORE STORMS START MOVG
IN. STILL HAVE NOT STARTED WEST SFC WND BUT XPCT THAT TO KICK IN
WITHIN THE NEXT HOUR. AS PER EARLIER DISCUSSION...MSTR
HEATING...AND UPR LVL DIVERGENCE FAVORABLE FOR MAKING STRONG TO
POSSIBLY SVR STORMS. SLOW MOVEMENT ALSO POSES FLASH FLOOD THREAT.

IF IT IS BIG TODAY THEN MON SHOULD BE A DOWN DAY...AND HAVE
BACKED OFF ON POPS...THEN BACK TO STANDARD PACKAGE FOR TUE.
TUS 5222. HOLBROOK

TUS...FFA ZONES 26>28 TIL 04Z.

In the hours before

Special weather statement, Sep 7, 11:41 AM MST, 5 hours 50 minutes before

AZZ019-026>030-072300-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1145 AM MST SUN SEP 7 1997...THIS PRODUCT IS NOT UPDATED

...MODERATE RISK OF SEVERE STORMS WITH HEAVY RAIN ESPECIALLY OVER
PIMA...SOUTHEAST PINAL...AND SANTA CRUZ COUNTIES...

                AREAL    PROBABILITY   RAIN GREATER THAN   STORM
              COVERAGE    OF SEVERE     1.00       2.00    MOTION

COCHISE          30          30          40         20      W 12
GRAHAM           30          30          40         20      W 10
GREENLEE         30          30          40         10     SW  8
TUCSON/ERN PIMA  50          50          70         50     NW 10
TOHONO OODHAM   50          40          60         30     NW 10
WESTERN PIMA     40          30          60         30     NW 10
SOUTHEAST PINAL  50          40          60         40     NW 10
SANTA CRUZ       70          50          75         50     NW 10

SYNOPSIS...VERY SIMILAR TODAY THAN YESTERDAY...WITH MOIST AIRMASS
OVER WESTERN AREA AND SOME DRY AIR IN EASTERN AREA. LIMITING
FACTOR ON SATURDAY WAS COOLING EFFECT FROM WEST WINDS BLOWING IN
OFF OF DESERT. THIS WILL NOT HAPPEN TODAY AND STORMS WILL FORM ON
MOUNTAINS AND WORK OUT INTO VALLEYS THROUGH THE AFTERNOON AND
EVENING. POTENTIAL FOR BOTH SEVERE STORMS AND HEAVY RAIN EXISTS.

*****************************************************************
KEY...
AREAL COVERAGE - PERCENT OF COUNTY OR AREA THAT WILL EXPERIENCE
                  THUNDERSTORMS
PROB OF SEVERE - THE PROBABILITY THAT ANY ONE OF THE STORMS WILL
                  REACH SEVERE LEVELS (DAMAGING WIND AND/OR
                  LARGE HAIL)
RAIN GRTR THAN - THE PROBABILITY THAT ANY ONE OF THE STORMS WILL
                  PRODUCE RAIN EXCEEDING 1 INCH OR 2 INCHES IN
                  ANY LOCATION
STORM MOTION   - GENERAL DIRECTION TO WHICH THE STORMS WILL
                  LIKELY MOVE AND SPEED IN MPH

NOTE...
VALID TIME IS FROM 12 NOON TO 12 MIDNIGHT OF THE DAY OF ISSUANCE
THIS PRODUCT IS NOT TO BE USED IN PLACE OF SEVERE THUNDERSTORM OR
FLASH FLOOD WARNINGS OR WATCHES. THIS PRODUCT IS ONLY USED FOR
OUTLOOK PURPOSES.

END/HOLBROOK

The office that day

Everything else NWS Tucson, AZ issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 8, 3:27 PM MST	Severe Thunderstorm Warning	TWC	Pima	48 min
Sep 8, 3:50 PM MST	Severe Thunderstorm Warning	TWC	Pinal	75 min

Nearby

Severe Thunderstorm Warnings in Arizona, 1997 Every severe thunderstorm warning in 1997

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.