Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 66, NWS Tucson, AZ

August 13, 1998Santa Cruz County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Aug 13, 1998, 2:35 PM MST for Santa Cruz County, Arizona. It was in force for 65 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 13, 1998, 2:35 PM MST (21:35 UTC)
Expired
Aug 13, 1998, 3:40 PM MST
In force
65 min
Issued by
NWS Tucson, AZ
Area
Whole counties

County Santa Cruz County, AZ

The radar

The Tucson radar (KEMX), 46 km from the middle of the area, began a volume at 21:34 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, 9.6 hours before the alert went out and 72 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-pSkew-T log-p diagram, Tuscon, AZ at 12:00Z on 1998-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 25 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tuscon, AZ at 12:00Z on 1998-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
25 J/kg
Mixed-layer CIN
-277 J/kg
Mixed-layer LCL
1762 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
44 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.

633 
WUUS1 KTUS 132138 RRA
SVRTUS
AZC023-132240-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
235 PM MST THU AUG 13 1998

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL AND SOUTHERN SANTA CRUZ COUNTY IN SOUTHERN ARIZONA

* UNTIL 340 PM MST

* AT 234 PM MST... DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM IN
  THE VICINITY OF RIO RICO...OR 8 MILES NORTH NORTHWEST OF NOGALES
  MOVING SOUTH AT 10 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  NOGALES                 BY 307 PM MST


T

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 13, 2:30 PM MST, 5 minutes earlier.

Area forecast discussion, Aug 13, 2:30 PM MST, 5 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST THU AUG 13 1998

SYNOPSIS...HIGH PRESSURE ALOFT OVER THE WESTERN GREAT BASIN WILL
DRIFT SLOWLY EAST DURING THE REMAINDER OF THIS WEEK. AN EAST TO
NORTHEAST WIND FLOW AROUND THIS HIGH PRESSURE SYSTEM WILL ALLOW
MONSOONAL MOISTURE AND THUNDERSTORMS TO PERSIST OVER SOUTHEAST
ARIZONA INTO THE UPCOMING WEEKEND.

DISCUSSION...THUNDERSTORM ACTIVITY BEGAN RATHER EARLY TODAY...BEFORE
NOON. EXPECTED TO SEE MORE ACTIVITY OVER THE FAR EASTERN RIM AREA
THAN SHOWING UP ON SATELLITE AT THIS TIME.  WITH INVERTED V SOUNDING
SEVERE WIND GUSTS POSSIBLE TONIGHT. SEE NO MECHANISM THROUGH 48
HOURS TO DECREASE MOISTURE ALREADY PRESENT. UPPER LEVEL HIGH
PRESSURE REMAINS CENTERED NORTH OF TUCSON FOR EAST TO NORTHEAST
STEERING FLOW. THIS IS FAVORABLE FOR STORMS MOVING OFF THE RIM
COUNTRY AND INTO THE VALLEYS.

TUS 534.

.TWC...SEVERE THUNDERSTORM WATCH 3 PM TO 9 PM.

In the hours before

Special weather statement, Aug 13, 12:45 PM MST, 1 hour 50 minutes before
AZZ019-029>035-140800-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST THU AUG 13 1998...THIS PRODUCT IS NOT UPDATED

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

COCHISE          40          30          60         40      SW 10
GRAHAM           50          40          60         40      SW 10
GREENLEE         50          40          60         45      SW 10
TUCSON/ERN PIMA  30          30          40         20      SW 10
TOHONO O'ODHAM   20          20          30         20      SW 10
WESTERN PIMA     20          20          30         20      SW 10
SOUTHEAST PINAL  20          30          30         20      SW 10
SANTA CRUZ       30          30          40         30      SW 10

SYNOPSIS...THE ATMOSPHERE ACROSS ALL OF SOUTHEAST ARIZONA IS MORE
UNSTABLE THAN YESTERDAY. AN UPPER LEVEL TROUGH OVER NORTHEAST
ARIZONA MAY ENHANCE THUNDERSTORM ACTIVITY OVER GRAHAM AND GREENLEE
COUNTIES. NORTH TO NORTHEAST WINDS WILL LIKELY PUSH THUNDERSTORMS
OFF THE MOGOLLON RIM INTO VALLEY LOCATIONS...THIS MAY ALLOW
THUNDERSTORMS TO CONTINUE INTO THE LATE NIGHT. BOTH SEVERE WIND
GUSTS AND FLASH FLOODING ARE POSSIBLE TODAY AND TONIGHT.
*****************************************************************
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 12:45 PM 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. CORRESPONDING GRAPHICS MAY BE @FOUND ON THE NWS
TUCSON INTERNET PAGE AT
HTTP://NIMBO.WRH.NOAA.GOV/TUCSON/SWO/SWO.SHTML

END/
Special weather statement, Aug 13, 12:45 PM MST, 1 hour 50 minutes before
AZZ019-029>035-140800-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST THU AUG 13 1998...THIS PRODUCT IS NOT UPDATED

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

COCHISE          40          30          60         40      SW 10
GRAHAM           50          40          60         40      SW 10
GREENLEE         50          40          60         45      SW 10
TUCSON/ERN PIMA  30          30          40         20      SW 10
TOHONO O'ODHAM   20          20          30         20      SW 10
WESTERN PIMA     20          20          30         20      SW 10
SOUTHEAST PINAL  20          30          30         20      SW 10
SANTA CRUZ       30          30          40         30      SW 10

SYNOPSIS...THE ATMOSPHERE ACROSS ALL OF SOUTHEAST ARIZONA IS MORE
UNSTABLE THAN YESTERDAY. AN UPPER LEVEL TROUGH OVER NORTHEAST
ARIZONA MAY ENHANCE THUNDERSTORM ACTIVITY OVER GRAHAM AND GREENLEE
COUNTIES. NORTH TO NORTHEAST WINDS WILL LIKELY PUSH THUNDERSTORMS
OFF THE MOGOLLON RIM INTO VALLEY LOCATIONS...THIS MAY ALLOW
THUNDERSTORMS TO CONTINUE INTO THE LATE NIGHT. BOTH SEVERE WIND
GUSTS AND FLASH FLOODING ARE POSSIBLE TODAY AND TONIGHT.
*****************************************************************
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 12:45 PM 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. CORRESPONDING GRAPHICS MAY BE @FOUND ON THE NWS
TUCSON INTERNET PAGE AT
HTTP://NIMBO.WRH.NOAA.GOV/TUCSON/SWO/SWO.SHTML

END/

Nearby

Severe Thunderstorm Warnings in Arizona, 1998Every severe thunderstorm warning in 1998

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.