Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 79, NWS Tucson, AZ

August 28, 1998Santa Cruz County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Aug 28, 1998, 5:38 PM MST for Santa Cruz 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
Aug 28, 1998, 5:38 PM MST (00:38 UTC)
Expired
Aug 28, 1998, 6:40 PM MST
In force
62 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 00:41 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.

What was reported inside it

TimeReportWhereRemark
Aug 28, 6:25 PM MSTThunderstorm Wind 61Rio Rico, 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

Tuscon, AZ (KTUS), launched 00:00Z, 0.6 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 00:00Z on 1998-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 103 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 1998-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 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
103 J/kg
Mixed-layer CIN
-247 J/kg
Mixed-layer LCL
2954 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
24 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.

696 
WUUS1 KTUS 290040 RRA
SVRTUS
AZC019-021-023-290140-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
538 PM MST FRI AUG 28 1998

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN PIMA COUNTY IN SOUTHERN ARIZONA
  SOUTHEASTERN PINAL COUNTY IN SOUTH CENTRAL ARIZONA
  SANTA CRUZ COUNTY IN SOUTHERN ARIZONA
  INCLUDING ELOY...GREATER TUCSON...VAIL...GREEN VALLEY AND SONOITA

* UNTIL 640 PM MST

* AT 535 PM MST...THE LINE OF SEVERE THUNDERSTORMS PERSISTED FROM
  NEAR OR SOUTHEAST OF FLORENCE THROUGH EASTERN TUCSON AND SOUTHEAST
  TO VAIL WITH PORTIONS JUST ENTERING FAR NORTHEAST SANTA CRUZ
  COUNTY. MOVEMENT CONTINUED TO THE WEST AND SOUTHWEST AT 15 MPH.

* THE SEVERE THUNDERSTORMS WILL BE NEAR...
  GREEN VALLEY             BY 545 PM
  SONOITA                  BY 547 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 Aug 28, 2:30 PM MST, 3 hours 8 minutes earlier.

Area forecast discussion, Aug 28, 2:30 PM MST, 3 hours 8 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST FRI AUG 28 1998

SYNOPSIS...SOME MOISTURE FROM NEW MEXICO HAS MOVED INTO SOUTHEAST
ARIZONA THIS AFTERNOON CAUSING AN INCREASE IN THUNDERSTORM ACTIVITY
MAINLY EAST OF TUCSON. THIS ADDITIONAL MOISTURE WILL HANG AROUND THE
AREA AT LEAST THROUGH SATURDAY. SOME DRIER AIR MAY MOVE INTO
SOUTHEAST ARIZONA ON SUNDAY FOR A DECREASE IN THUNDERSTORM ACTIVITY.

DISCUSSION...MORE THUNDERSTORM ACTIVITY OVER SOUTHEAST ARIZONA
THIS AFTERNOON THEN EXPECTED DUE TO AN INCREASE IN MOISTURE FROM THE
EAST AND A LITTLE COOL ADVECTION IN THE MID-LEVELS. WILL GO WITH
ISOLATED STORMS WEST TO SCATTERED EAST THIS EVENING

THE FORECAST FOR THE NEXT COUPLE OF DAYS IS NOT CLEAR CUT. IF YOU
WENT STRICTLY BY THE MODELS(A FOOLISH THING THIS TIME OF YEAR) YOU
WOULD GO WITH A BIG DECREASE IN THUNDERSTORM ACTIVITY OVER THE
WEEKEND AS MODELS GRAB DRY AIR CURRENTLY OVER THE MIDWEST AND BRING
IT INTO SOUTHEAST ARIZONA BEGINNING SATURDAY AFTERNOON AND
CONTINUING THROUGH SUNDAY FOR HARDLY ANY OR NO THUNDERSTORM
ACTIVITY. HOWEVER THE THUNDERSTORM ACTIVITY THATS DEVELOPING TODAY
WILL ADD MOISTURE TO THE ATMOSPHERE AND I AM NOT SURE IF THE DRY AIR
THE MODELS WANT TO PUSH IN OVER THE WEEKEND WILL BE ENOUGH TO
COMPLETELY OR NEARLY SQUASH ALL THUNDERSTORM ACTIVITY PARTICULARLY
ON SATURDAY. WITH THAT IN MIND THINK THE PRUDENT COURSE WILL BE TO
CONTINUE WITH ISOLATED COVERAGE WEST AND LOW SCATTERED COVERAGE EAST
SATURDAY THEN SCALE IT BACK TO SLIGHT CHANCE WORDING WEST ON SUNDAY
AND ISOLATED EAST. A LITTLE COOLER TEMPERATURES SATURDAY(JUST A FEW
DEGREES) DUE TO LOWERING HEIGHTS AS UPPER HIGHS MOVES FURTHER AWAY
THEN ABOUT THE SAME SUNDAY DUE TO DRIER AIR EVEN THOUGH HEIGHTS
DECREASE A LITTLE MORE.

TUS 3221. COLLINS

.TWC...NONE.

In the hours before

Special weather statement, Aug 28, 12:45 PM MST, 4 hours 53 minutes before
AZZ019-029>035-290700-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST FRI AUG 28 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          30          20         10      W 15
GRAHAM           30          30          20         10      W 15
GREENLEE         30          20          20         10      W 15
TUCSON/ERN PIMA  20          20          10          0      W 15
TOHONO OODHAM   10          20          10          0      W 15
WESTERN PIMA      5          20           5          0      W 15
SOUTHEAST PINAL  10          20           5          0      W 15
SANTA CRUZ       30          30          20         10      W 15

SYNOPSIS...SOME MOISTURE FROM NEW MEXICO WILL MOVE INTO SOUTHEAST
ARIZONA THIS AFTERNOON FOR BETTER THUNDERSTORM ACTIVITY COMPARED TO
YESTERDAY. HOWEVER STRONG UPPER HIGH IN THE VICINITY OF SOUTHEAST
ARIZONA WILL INHIBIT THUNDERSTORM DEVELOPMENT TO SOME EXTENT SO
EXPECTING ONLY ISOLATED ACTIVITY IN THE WEST AND SCATTERED ACTIVITY
IN THE EAST.
*****************************************************************
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/CEC
Special weather statement, Aug 28, 12:45 PM MST, 4 hours 53 minutes before
AZZ019-029>035-290700-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST FRI AUG 28 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          30          20         10      W 15
GRAHAM           30          30          20         10      W 15
GREENLEE         30          20          20         10      W 15
TUCSON/ERN PIMA  20          20          10          0      W 15
TOHONO OODHAM   10          20          10          0      W 15
WESTERN PIMA      5          20           5          0      W 15
SOUTHEAST PINAL  10          20           5          0      W 15
SANTA CRUZ       30          30          20         10      W 15

SYNOPSIS...SOME MOISTURE FROM NEW MEXICO WILL MOVE INTO SOUTHEAST
ARIZONA THIS AFTERNOON FOR BETTER THUNDERSTORM ACTIVITY COMPARED TO
YESTERDAY. HOWEVER STRONG UPPER HIGH IN THE VICINITY OF SOUTHEAST
ARIZONA WILL INHIBIT THUNDERSTORM DEVELOPMENT TO SOME EXTENT SO
EXPECTING ONLY ISOLATED ACTIVITY IN THE WEST AND SCATTERED ACTIVITY
IN THE EAST.
*****************************************************************
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/CEC

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 28, 5:03 PM MSTSevere Thunderstorm WarningTWCPima37 min
Aug 28, 5:38 PM MSTSevere Thunderstorm WarningTWCPima, Pinal62 min
Aug 28, 6:44 PM MSTSevere Thunderstorm WarningTWCSanta Cruz46 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; radar from the NEXRAD Level II archive.