Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 7, NWS Tucson, AZ

July 4, 1998Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Jul 4, 1998, 6:02 PM MST for Pima County, Arizona. It was in force for 48 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
Jul 4, 1998, 6:02 PM MST (01:02 UTC)
Expired
Jul 4, 1998, 6:50 PM MST
In force
48 min
Issued by
NWS Tucson, AZ
Area
Whole counties

County Pima County, AZ

The radar

The Tucson radar (KEMX), 112 km from the middle of the area, began a volume at 01:06 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 00:00Z, 1.0 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-pSkew-T log-p diagram, Tuscon, AZ at 00:00Z on 1998-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 428 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 00:00Z on 1998-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 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
428 J/kg
Mixed-layer CIN
-138 J/kg
Mixed-layer LCL
2020 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
-15 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.

162 
WUUS1 KTUS 050104 RRA
SVRTUS
AZC019-050150-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
602 PM MST SAT JUL 4 1998

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN PIMA COUNTY IN SOUTHERN ARIZONA

* UNTIL 650 PM MST

* AT 559 PM MST... DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 19
  MILES SOUTHWEST OF SELLS OR 17 MILES WEST NORTHWEST OF SAN MIGUEL
  MOVING NORTH AT 10 MPH.



VPH

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 Jul 4, 2:30 PM MST, 3 hours 32 minutes earlier.

Area forecast discussion, Jul 4, 2:30 PM MST, 3 hours 32 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST SAT JUL 4 1998

SYNOPSIS...AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BUILD OVER
SOUTHERN AND CENTRAL ARIZONA. FLOW ALOFT WILL BECOME MORE
SOUTHEASTERLY. THIS WILL REGENERATE AFTERNOON AND EVENING
THUNDERSTORM ACTIVITY THROUGH MONDAY.

DISCUSSION...AREAS THAT HAD SIGNIFICANT CLOUD COVER THIS MORNING
SHOWING LITTLE THUNDRESTORM ACTIVITY SO FAR. WILL DROP THESE AREAS
FROM SCATTERED TO ISOLATED FOR THIS EVENING.  MODEL MOISTURE FIELDS
ARE OF LITTLE USE. AT 500 MB THE RIDGE BEGINS BUILDING OVER
SOUTHEAST ARIZONA ON SUNDAY...AND BY MONDAY THE AVN HAS IT NORTH OF
TUCSON. THE 6-10 AVERAGE HAS THE HIGH CENTER NEAR THE FOUR CORNERS
AREA. NO STRONG SURFACE WINDS TO BLOW OUT THE MOISTURE. SO ISOLATED
THUNDERSTORMS WEST AND SCATTERED EAST. AFTERNOON TEMPERATURES WILL
DEPEND ON CLOUD COVER. SO GOING WITH STANDARD MONSOON FORECAST
THROUGH 5 DAYS.

TUS 3222.

4.TWC...NONE.

In the hours before

Special weather statement, Jul 4, 12:13 PM MST, 5 hours 49 minutes before
AZZ019-026>030-050700-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST SAT JUL 04 1998...THIS PRODUCT IS NOT UPDATED

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

COCHISE          20          30          40         20     N 15
GRAHAM           40          30          40         20     N 15
GREENLEE         50          50          60         20     N 15
TUCSON/ERN PIMA  50          50          60         30     N 15
TOHONO OODHAM   40          50          50         20     N 15
WESTERN PIMA     30          30          20         10     N 15
SOUTHEAST PINAL  30          50          50         20     N 15
SANTA CRUZ       60          50          60         30     N 15

SYNOPSIS...
THE ATMOSPHERE IS QUITE MOIST AND UNSTABLE...ALLOWING THUNDERSTORMS
TO DEVELOP EARLIER IN THE DAY. THEY WILL DEVELOP OVER THE MOUNTAINS
FIRST THEN MOVE INTO VALLEY LOCATIONS. STRONG WINDS AND LOCAL FLASH
FLOODING IS POSSIBLE.
*****************************************************************
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/

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 4, 6:31 PM MSTFlash Flood WarningTWCPima119 min
Jul 5, 7:46 AM MSTFlash Flood WarningTWCCochise119 min
Jul 5, 7:57 AM MSTFlash Flood WarningTWCPima2 hr

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.