Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 83, NWS Tucson, AZ

September 5, 1998Pinal County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Sep 5, 1998, 3:53 PM MST for Pinal County, Arizona. It was in force for 62 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Sep 5, 1998, 3:53 PM MST (22:53 UTC)
Expired
Sep 5, 1998, 4:55 PM MST
In force
62 min
Issued by
NWS Tucson, AZ
Area
Whole counties

County Pinal County, AZ

What was reported inside it

TimeReportWhereRemark
Sep 5, 4:00 PM MSTThunderstorm Wind 56Oracle, 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

Phoenix, AZ (KPHX), launched 12:00Z, 10.9 hours before the alert went out and 82 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, Phoenix, AZ at 12:00Z on 1998-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 454 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 12:00Z on 1998-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 square meters per square second.193958Sfc1 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
454 J/kg
Mixed-layer CIN
-135 J/kg
Mixed-layer LCL
1195 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
167 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.8

Open this sounding in Storm Lab

The text

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

613 
WUUS1 KTUS 052254 RRA
SVRTUS
AZC021-052355-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
353 PM MST SAT SEP 5 1998

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN PINAL COUNTY IN SOUTH CENTRAL ARIZONA
  INCLUDING ORACLE JUNCTION...ORACLE AND MAMMOTH.

* UNTIL 455 PM MST

* AT 351 PM MST... DOPPLER RADAR INDICATED AN AREA OF SEVERE
  THUNDERSTORMS MOVING FROM NORTHEAST PIMA COUNTY INTO SOUTHEAST
  PINAL COUNTY. MOVEMENT WILL CONTINUE TO THE NORTH AND NORTHWEST
  AT 15 TO 20 MPH.

* THE SEVERE THUNDERSTORMS WILL BE NEAR...
  ORACLE                    BY 400 PM
  MAMMOTH                   BY 405 PM

MEYER

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 5, 2:50 PM MST, 1 hour 3 minutes earlier.

Area forecast discussion, Sep 5, 2:50 PM MST, 1 hour 3 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
250 PM MST SAT SEP 5 1998

SYNOPSIS...A COMBINATION OF RESIDUAL MOISTURE AND SUPPORT FROM A LOW
PRESSURE SYSTEM OVER SOUTHERN CALIFORNIA WILL PROVIDE ANOTHER ROUND
OF SCATTERED SHOWERS AND THUNDERSTORMS THROUGH EARLY TONIGHT. DRIER
AIR WILL MOVE INTO THE REGION THROUGH THE REST OF THE HOLIDAY WEEKEND
FOR A GRADUAL DECREASE IN THUNDERSTORM ACTIVITY. HOWEVER...DEEPER
MOISTURE IS EXPECTED TO RETURN TO THE SOUTHEAST PORTION OF THE GRAND
CANYON STATE BY THE MIDDLE OF NEXT WEEK.

DISCUSSION...SCATTERED SHOWERS AND THUNDERSTORMS REDEVELOPED THIS
AFTERNOON OVER GENERALLY THE SAME AREA WHERE STEADY RAIN FELL EARLY
THIS MORNING. PWATER AND CAPE VALUES SUPPORT STRONG STORMS WITH
HEAVY RAINFALL THIS EVENING MAINLY IN CENTRAL/EASTERN PIMA AND SANTA
CRUZ COUNTIES. EXPECT THESE STORMS TO GRADUALLY TAPER OFF THIS
EVENING WITH MOSTLY CLEAR TO PARTLY CLOUDY SKIES OVERNIGHT. UPPER LOW
SPINNING OVER SOUTHERN CALIFORNIA CONTINUES TO BE A CONCERN AS
WEAK IMPULSES ROTATE INTO THE STATE. AT THIS TIME...DO NOT EXPECT
ANOTHER DISTURBANCE TO IMPACT SOUTHEASTERN ARIZONA LATE TONIGHT AND
EARLY TOMORROW. THEREFORE...WE SHOULD NOT SEE A REPEAT OF THE PAST
TWO MORNINGS WERE SHOWERS DEVELOP ALONG THE SANTA CRUZ VALLEY FROM
NOGALES TO TUCSON. BUT THIS IS SOMETHING FOR LATER SHIFTS TO WATCH.
MODELS CONTINUE TO SHOW DRIER AIR MOVING INTO THE SOUTHEAST THE
NEXT FEW DAYS FOR A GRADUAL DECREASE IN SHOWER AND THUNDERSTORM
ACTIVITY. TUS 3111. DAVIS.

.TWC...NONE.

In the hours before

Special weather statement, Sep 5, 10:50 AM MST, 5 hours 3 minutes before
AZZ019-029>035-060700-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1050 AM MST SAT SEP 5 1998...THIS PRODUCT IS NOT UPDATED

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

COCHISE          30          20          40          0     NW 15
GRAHAM           30          20          40          0     NW 15
GREENLEE         30          20          40          0     NW 15
TUCSON/ERN PIMA  30          20          40          0     NW 15
TOHONO OODHAM   30          40          60          0     NW 15
WESTERN PIMA     30          40          60          0     NW 15
SOUTHEAST PINAL  30          20          40          0     NW 15
SANTA CRUZ       30          20          40          0     NW 15

SYNOPSIS...A WEAK DISTURBANCE ROTATING AROUND A LOW PRESSURE
SYSTEM OVER SOUTHERN CALIFORNIA WILL INTERACT WITH RESIDUAL LOW
LEVEL MOISTURE ACROSS THE REGION TO PRODUCE AFTERNOON AND EVENING
THUNDERSTORMS. A COMBINATION OF SUFFICIENT DAYTIME HEATING...DEEPER
MOISTURE...AND LARGE SCALE LIFT WILL FOCUS STRONGER STORMS OVER
CENTRAL AND WESTERN PIMA COUNTY TODAY. OTHER THUNDERSTORMS WILL
INITIALLY FORM OVER THE MOUNTAINS AND HIGHER TERRAIN OF THE
SOUTHEAST...WITH A FEW MAKING THEIR WAY INTO THE LOWER DESERT
VALLEYS LATE THIS AFTERNOON AND EVENING.
*****************************************************************
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/JTD
Special weather statement, Sep 5, 10:50 AM MST, 5 hours 3 minutes before
AZZ019-029>035-060700-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1050 AM MST SAT SEP 5 1998...THIS PRODUCT IS NOT UPDATED

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

COCHISE          30          20          40          0     NW 15
GRAHAM           30          20          40          0     NW 15
GREENLEE         30          20          40          0     NW 15
TUCSON/ERN PIMA  30          20          40          0     NW 15
TOHONO OODHAM   30          40          60          0     NW 15
WESTERN PIMA     30          40          60          0     NW 15
SOUTHEAST PINAL  30          20          40          0     NW 15
SANTA CRUZ       30          20          40          0     NW 15

SYNOPSIS...A WEAK DISTURBANCE ROTATING AROUND A LOW PRESSURE
SYSTEM OVER SOUTHERN CALIFORNIA WILL INTERACT WITH RESIDUAL LOW
LEVEL MOISTURE ACROSS THE REGION TO PRODUCE AFTERNOON AND EVENING
THUNDERSTORMS. A COMBINATION OF SUFFICIENT DAYTIME HEATING...DEEPER
MOISTURE...AND LARGE SCALE LIFT WILL FOCUS STRONGER STORMS OVER
CENTRAL AND WESTERN PIMA COUNTY TODAY. OTHER THUNDERSTORMS WILL
INITIALLY FORM OVER THE MOUNTAINS AND HIGHER TERRAIN OF THE
SOUTHEAST...WITH A FEW MAKING THEIR WAY INTO THE LOWER DESERT
VALLEYS LATE THIS AFTERNOON AND EVENING.
*****************************************************************
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/JTD

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 5, 2:17 PM MSTSevere Thunderstorm WarningTWCPima48 min
Sep 5, 3:03 PM MSTSevere Thunderstorm WarningTWCPima62 min

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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.