Alert archive / Arizona / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 34, NWS Tucson, AZ

August 4, 1997Pima County, Santa Cruz County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Aug 4, 1997, 1:39 PM MST for Pima County, Santa Cruz County, Arizona. It was in force for 51 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: Aug 4, 1997, 1:39 PM MST (20:39 UTC)
Expired: Aug 4, 1997, 2:30 PM MST
In force: 51 min
Issued by: NWS Tucson, AZ
Area: Whole counties

Counties Pima County, AZ, Santa Cruz County, AZ

The radar

The Tucson radar (KEMX), 66 km from the middle of the area, began a volume at 20:41 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, 8.7 hours before the alert went out and 56 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: 481 J/kg
Mixed-layer CIN: -166 J/kg
Mixed-layer LCL: 1666 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 9 m²/s²
0-3 km storm-relative helicity: 68 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KTUS 042043 RRA
SVRTUS
AZC019-023-042130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
139 PM MST MON AUG 4 1997

THE NATIONAL WEATHER SERVICE IN TUCSON AZ HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 230 PM MST
FOR PEOPLE IN THE FOLLOWING LOCATIONS...

IN SOUTHERN ARIZONA

   ...SOUTHEASTERN PIMA COUNTY
   ...NORTHERN SANTA CRUZ COUNTY
 
AT 140 PM MST...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 31
MILES SOUTH OF SOUTHWEST TUCSON OR 7 MILES EAST OF ARIVACA JUNCTION
MOVING NORTH NORTHWEST AT 10 MPH.

THIS STORM WILL AFFECT...
INTERSTATE 19 ABOUT 8 MILES NORTH OF ARIVACA JUNCTION
BY 154 PM MST

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 4, 9:49 AM MST, 3 hours 50 minutes earlier.

Area forecast discussion, Aug 4, 9:49 AM MST, 3 hours 50 minutes before

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
930 AM MST MON AUG 4 1997

INTERESTING DAY SHAPING UP FOR SOUTHEAST ARIZONA.  TUS SOUNDING
UNSTABLE WITH A CONVECTIVE TEMPERATURE OF 95 DEGREES AND PERHAPS MORE
CAPE THAN ANY DAY THIS SUMMER.  WILL CERTAINLY HEAT MORE TODAY THAN
PAST COUPLE OF DAYS SO EXPECT MORE AND STRONGER CONVECTION THIS
AFTERNOON OVER SOUTHEAST ARIZONA THAN OVER THE WEEKEND.

COUPLE OF ITEMS OF INTEREST INCLUDE THE EASTERLY WAVE VISIBLE ON
WATER VAPOR PICTURES AROUND 104 W...LARGE CONVECTIVE SYSTEM THAT
DEVELOPED AND PROPAGATED OVER THE GULF OF CALIFORNIA LAST NIGHT...AND
SHORT WAVE OVER WESTERN ARIZONA WHICH MOVED NORTHWARD FROM BAJA OVER
THE WEEKEND.  WATER VAPOR LOOPS SHOWS THAT THE AFFECT OF THE EASTERLY
WAVE TO BECOME THE DOMINANT FEATURE OVER SOUTHERN AZ...NORTHERN MX AS
DEFORMATION ZONE/MOISTURE BOUNDARY PROPAGATING WESTWARD WITH TIME.

WILL CONTINUE TO ASSIMILATE ABOVE INFORMATION FOR THE CONVECTIVE
OUTLOOK AND BECOME MORE DEFINITIVE REGARDING TIMING/PLACEMENT OF
CONVECTION...BUT EXPECT A VERY ACTIVE CONVECTIVE DAY OVER TUCSON CWA
DURING THIS AFTERNOON AND EVENING.

NO CHANGES TO ZONE/LOCAL FORECASTS ATTM. TUS 353. DRB|

TUS...NONE.

In the hours before

Special weather statement, Aug 4, 11:56 AM MST, 1 hour 43 minutes before

AZZ019-026>030-042300-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1145 AM MST MON AUG 4 1997...THIS PRODUCT IS NOT UPDATED.

...THERE IS A MODERATE RISK OVER SEVERE THUNDERSTORMS WITH HEAVY RAIN
OVER PARTS OF SOUTHEAST ARIZONA THIS AFTERNOON...

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

COCHISE          40          30          50         20     NW 12
GRAHAM           40          35          60         30     NW 10
GREENLEE         50          20          50         25     NW  8
TUCSON/ERN PIMA  40          50          70         40     NW 10
TOHONO OODHAM   35          40          70         40     NW  7
WESTERN PIMA     25          15          40         20     NW  4
SOUTHEAST PINAL  35          45          70         40     NW 10
SANTA CRUZ       50          50          70         40     NW 10

SYNOPSIS...
ABUNDANT SUNSHINE...LOW LEVEL MOISTURE...AND MODERATE INSTABILITY
WILL PRODUCE STRONG AND LOCALLY SEVERE CONVECTION OVER SOUTHEAST
ARIZONA THIS AFTERNOON.  DEVELOPMENT SHOULD OCCUR OVER THE HIGHER
TERRAIN FROM AROUND BISBEE TOWARD SAFFORD AND PROPAGATE WESTWARD
DURING THE LATE AFTERNOON.  DUE TO THE HIGH LOW LEVEL MOISTURE AND
RELATIVELY SLOW MOVEMENT OF THE STORMS LOCALLY HEAVY RAINFALL IS
LIKELY.  SOME STORMS WILL LIKELY PRODUCE SEVERE WIND.

*****************************************************************
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/BRIGHT

Special weather statement, Aug 4, 12:32 PM MST, 1 hour 7 minutes before

AZZ019-026>030-042300-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1145 AM MST MON AUG 4 1997...THIS PRODUCT IS NOT UPDATED...RETRAN

...THERE IS A MODERATE RISK OVER SEVERE THUNDERSTORMS WITH HEAVY RAIN
OVER PARTS OF SOUTHEAST ARIZONA THIS AFTERNOON...

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

COCHISE          40          30          50         20     NW 12
GRAHAM           40          35          60         30     NW 10
GREENLEE         50          20          50         25     NW  8
TUCSON/ERN PIMA  40          50          70         40     NW 10
TOHONO OODHAM   35          40          70         40     NW  7
WESTERN PIMA     25          15          40         20     NW  4
SOUTHEAST PINAL  35          45          70         40     NW 10
SANTA CRUZ       50          50          70         40     NW 10
SYNOPSIS...
ABUNDANT SUNSHINE...LOW LEVEL MOISTURE...AND MODERATE INSTABILITY
WILL PRODUCE STRONG AND LOCALLY SEVERE CONVECTION OVER SOUTHEAST
ARIZONA THIS AFTERNOON.  DEVELOPMENT SHOULD OCCUR OVER THE HIGHER
TERRAIN FROM AROUND BISBEE TOWARD SAFFORD AND PROPAGATE WESTWARD
DURING THE LATE AFTERNOON.  DUE TO THE HIGH LOW LEVEL MOISTURE AND
RELATIVELY SLOW MOVEMENT OF THE STORMS LOCALLY HEAVY RAINFALL IS
LIKELY.  SOME STORMS WILL LIKELY PRODUCE SEVERE WIND.

*****************************************************************
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/BRIGHT

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 3, 5:20 PM MST	Flash Flood Warning	TWC	Cochise	55 min
Aug 3, 5:20 PM MST	Flash Flood Warning	TWC	Cochise	85 min
Aug 4, 1:02 PM MST	Severe Thunderstorm Warning	TWC	Pima	48 min
Aug 4, 2:06 PM MST	Severe Thunderstorm Warning	TWC	Pima	44 min
Aug 4, 2:39 PM MST	Severe Thunderstorm Warning	TWC	Pinal	46 min
Aug 4, 3:22 PM MST	Severe Thunderstorm Warning	TWC	Pinal	33 min
Aug 4, 4:17 PM MST	Severe Thunderstorm Warning	TWC	Pima	63 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; radar from the NEXRAD Level II archive.