Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 55, NWS Tucson, AZ

August 7, 1998Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Aug 7, 1998, 5:35 PM MST for Pima County, Arizona. It was in force for 45 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 7, 1998, 5:35 PM MST (00:35 UTC)
Expired
Aug 7, 1998, 6:20 PM MST
In force
45 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 00:36 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, 0.6 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 1998-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 347 joules per kilogram.LCLEL10008507005003002001001 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 1998-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 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
347 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
3195 m above ground
0-6 km bulk shear
2 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
47 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.

243 
WUUS1 KTUS 080037 RRA
SVRTUS
AZC019-080120-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
535 PM MST FRI AUG 7 1998

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

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

* UNTIL 620 PM MST

* AT 535 PM MST...DOPPLER RADAR SHOWED A SEVERE THUNDERSTORM 10
  MILES EAST OF THREE POINTS AND 5 MILES SOUTHEAST OF RYAN FIELD
  MOVING WEST AT 15 MPH. THIS STORM WILL BE CAPABLE OF PRODUCING
  WIND GUST TO 65 MPH AND HEAVY RAIN.

* THIS SEVERE THUNDERSTORM WILL AFFECT...
  RYAN FIELD         BY 545 PM


MCCOLLUM

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 7, 2:30 PM MST, 3 hours 5 minutes earlier.

Area forecast discussion, Aug 7, 2:30 PM MST, 3 hours 5 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST FRI AUG 7 1998

SYNOPSIS...THUNDERSTORM ACTIVITY WILL BE ON THE INCREASE THOUGH THE
WEEKEND AS MORE MOISTURE ENTERS THE STATE.

DISCUSSION...TODAY LUKS VERY SIMILAR TO WED EXCEPT DONT THINK WE
WILL SEE AS MUCH TRAINING ON THE MTNS. LUKS LIKE THING WILL GET
ORGANIZED THIS AFTN AND THERE IS ENUF CAPE TO GET STORMS OFF MTNS
INTO VALLEYS. COLD ALOFT SO HAIL IS A THREAT AND COULD SEE SOME
HEAVY RAIN IN SPOTS BUT NOT EXPECTING A HEAVY RAIN EVENT. STILL HAVE
LEFT WORDING BEEFED UP IN CASE MSTR GETS BETTER BY EVENING. ATTN
THEN TURNS TO TROPICAL MSTR MOVG UP ASSOCD WITH THE DEPRESSION.
MODELS PUSH THIS NWD OVR THE WEEKEND. SO HAVE BROUGHT TEMPS DOWN AND
POPS UP. THIS COULD GET VERY WET IF MODELS MSTR FIELDS ARE CORRECT.
FOR NOW JUST MONITORING. TUS 4344. HOLBROOK

.TWC...NONE.

In the hours before

Special weather statement, Aug 7, 12:45 PM MST, 4 hours 50 minutes before
AZZ019-029>035-080700-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST THU AUG 7 1998...THIS PRODUCT IS NOT UPDATED

...MODERATE RISK OF SEVERE WEATHER AND FLASH FLOODING ACROSS ALL
OF SOUTHEAST ARIZONA EXCEPT FOR GRAHAM AND GREENLEE COUNTIES...

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

COCHISE          20          10          15          5      W  10
GRAHAM           20          10          15          5      SW 10
GREENLEE         20          10          15          5      SW 10
TUCSON/ERN PIMA  40          25          50         20      W  10
TOHONO OODHAM   40          25          40         15      NW 10
WESTERN PIMA     40          20          40         15      NW 10
SOUTHEAST PINAL  40          20          40         15      W  10
SANTA CRUZ       50          30          50         25      W  10

SYNOPSIS...MOISTURE HAS MOVED BACK SOUTHERN ARIZONA FROM THE SOUTH
WHILE THE EASTERN THREE COUNTIES REMAIN RELATIVELY DRY. MID LEVEL
WINDS ARE FAVORABLE TO MOVE STORMS WESTWARD INTO DESERT AND HIGHER
LEVEL WINDS WILL PUSH ANVILS BACK TO THE EAST...ALSO A FAVORABLE
SCENARIO. SO WE ARE EXPECTING AN UPSWING IN THUNDERSTORM ACTIVITY
ACROSS THREE WESTERN ZONES.
*****************************************************************
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/VPH
Special weather statement, Aug 7, 12:45 PM MST, 4 hours 50 minutes before
AZZ019-029>035-080700-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST THU AUG 7 1998...THIS PRODUCT IS NOT UPDATED

...MODERATE RISK OF SEVERE WEATHER AND FLASH FLOODING ACROSS ALL
OF SOUTHEAST ARIZONA EXCEPT FOR GRAHAM AND GREENLEE COUNTIES...

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

COCHISE          20          10          15          5      W  10
GRAHAM           20          10          15          5      SW 10
GREENLEE         20          10          15          5      SW 10
TUCSON/ERN PIMA  40          25          50         20      W  10
TOHONO OODHAM   40          25          40         15      NW 10
WESTERN PIMA     40          20          40         15      NW 10
SOUTHEAST PINAL  40          20          40         15      W  10
SANTA CRUZ       50          30          50         25      W  10

SYNOPSIS...MOISTURE HAS MOVED BACK SOUTHERN ARIZONA FROM THE SOUTH
WHILE THE EASTERN THREE COUNTIES REMAIN RELATIVELY DRY. MID LEVEL
WINDS ARE FAVORABLE TO MOVE STORMS WESTWARD INTO DESERT AND HIGHER
LEVEL WINDS WILL PUSH ANVILS BACK TO THE EAST...ALSO A FAVORABLE
SCENARIO. SO WE ARE EXPECTING AN UPSWING IN THUNDERSTORM ACTIVITY
ACROSS THREE WESTERN ZONES.
*****************************************************************
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/VPH

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 7, 5:20 PM MSTSevere Thunderstorm WarningTWCPima45 min
Aug 7, 6:06 PM MSTSevere Thunderstorm WarningTWCPima44 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.