Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 14, NWS Tucson, AZ

July 17, 1998Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Jul 17, 1998, 6:25 PM MST for Pima County, Arizona. It was in force for 60 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 17, 1998, 6:25 PM MST (01:25 UTC)
Expired
Jul 17, 1998, 7:25 PM MST
In force
60 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 01:25 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, 1.4 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 1998-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 979 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 1998-07-18The 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
979 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
3214 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
38 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

The text

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

456 
WUUS1 KTUS 180126 RRA
SVRTUS
AZC019-180225-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
625 PM MST FRI JUL 17 1998

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

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

* UNTIL 725 PM MST...THIS DOES NOT INCLUDE METROPOLITAN TUCSON

* AT 625 PM MST... DOPPLER RADAR AND SPOTTER REPORTS INDICATED AN
  AREA OF SEVERE THUNDERSTORMS ALONG HIGHWAY 86 NEAR THREE POINTS
  AND RYAN FIELD. THIS AREA EXTENDED SOUTHWARD TO THE SIERRITA
  MOUNTAINS WEST OF GREEN VALLEY. STORM MOVEMENT WAS TO THE
  SOUTHWEST AT 15 TO 25 MPH.

* THE SEVERE THUNDERSTORMS WILL BE NEAR...
  THREE POINTS BY 640 PM
  KITT PEAK BY 700 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 Jul 17, 2:30 PM MST, 3 hours 55 minutes earlier.

Area forecast discussion, Jul 17, 2:30 PM MST, 3 hours 55 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST FRI JUL 17 1998

SYNOPSIS...AN EASTERLY AIRFLOW AROUND AN UPPER HIGH CENTERED OVER
SOUTHERN NEVADA AND SOUTHWEST UTAH WILL CONTINUE TO INCREASE THE
MOISTURE OVER SOUTHEAST ARIZONA FOR AN UPSWING IN THUNDERSTORM
ACTIVITY THROUGH THE WEEKEND.

DISCUSSION...THE AIR MASS IS A LITTLE MORE MOIST TODAY THAN
YESTERDAY PER TUCSON SOUNDING THIS MORNING AND A LITTLE HIGHER
SURFACE DEW POINTS. THIS MOISTENING TREND WILL CONTINUE NEXT 24
HOURS AS HIGHER MOISTURE VALUES RESIDING TO OUR EAST IN NEW MEXICO
WILL BE ADVECTED INTO SOUTHEAST ARIZONA IN THE EASTERLY FLOW.
MODIFIED SOUNDING SHOWS CAPE AROUND 1100J/KG THIS AFTERNOON WHICH IS
A LITTLE HIGHER THAN YESTERDAY SO SHOULD SEE ANOTHER GOOD FIREWORKS
SHOW THIS EVENING ON THE LOWER DESERTS AS OUTFLOWS FROM THE RIM
COUNTRY PROPAGATE INTO THE LOWER DESERTS THIS EVENING AND INITIATE
THUNDERSTORMS. MAIN CONCERN AGAIN WILL BE STRONG DOWNBURST WINDS DUE
TO INVERTED V TYPE SOUNDING. ANOTHER THING THAT WILL HELP BEEF UP
THUNDERSTORM ACTIVITY LATE THIS AFTERNOON AND EVENING IS A CYCLONIC
CIRCULATION SEEN IN WATER VAPOR IMAGERY OVER WEST CENTRAL NEW MEXICO
WHICH WILL ADD DYNAMICAL SUPPORT TO THUNDERSTORM FORMATION AS IT
MOVES ACROSS SOUTHEAST ARIZONA THIS EVENING. SATURDAY AND SUNDAY
WILL CONTINUE TO BE ACTIVE AS THIS EASTERLY FLOW CONTINUES. THIS
SAME PATTERN CONTINUES THROUGH MIDWEEK.

TUS 5343. COLLINS

.TWC...NONE.

In the hours before

Special weather statement, Jul 17, 12:45 PM MST, 5 hours 40 minutes before
AZZ019-029>035-180700-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST FRI JUL 17 1998...THIS PRODUCT IS NOT UPDATED

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

COCHISE          50          25          50         10     SW 20
GRAHAM           55          30          50         10     SW 20
GREENLEE         65          25          50         10     SW 15
TUCSON/ERN PIMA  50          35          50         10     SW 20
TOHONO OODHAM   45          30          40          5     SW 20
WESTERN PIMA     30          30          30          0     SW 20
SOUTHEAST PINAL  45          40          45         10     SW 20
SANTA CRUZ       50          35          45         10     SW 20

SYNOPSIS...MOIST AND UNSTABLE. STORMS WILL FORM OVER HIGHER
TERRAIN...ESPECIALLY THE MOGOLLON RIM...AND MOVE DOWN INTO VALLEY
LOCATIONS WITH A STRONG NORTHEASTERLY FLOW ALOFT. DYNAMICS WILL
ENHANCE THUNDERSTORMS INTO THE EVENING HOURS WITH A MODERATE CHANCE
OF SEVERE THUNDERSTORMS ALONG WITH RAINFALL AMOUNTS AT 1 INCH NOT
UNCOMMON. STORMS MAY BE SUSTAINED INTO THE LATE 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/CEC
Special weather statement, Jul 17, 12:45 PM MST, 5 hours 40 minutes before
AZZ019-029>035-180700-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST FRI JUL 17 1998...THIS PRODUCT IS NOT UPDATED

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

COCHISE          50          25          50         10     SW 20
GRAHAM           55          30          50         10     SW 20
GREENLEE         65          25          50         10     SW 15
TUCSON/ERN PIMA  50          35          50         10     SW 20
TOHONO OODHAM   45          30          40          5     SW 20
WESTERN PIMA     30          30          30          0     SW 20
SOUTHEAST PINAL  45          40          45         10     SW 20
SANTA CRUZ       50          35          45         10     SW 20

SYNOPSIS...MOIST AND UNSTABLE. STORMS WILL FORM OVER HIGHER
TERRAIN...ESPECIALLY THE MOGOLLON RIM...AND MOVE DOWN INTO VALLEY
LOCATIONS WITH A STRONG NORTHEASTERLY FLOW ALOFT. DYNAMICS WILL
ENHANCE THUNDERSTORMS INTO THE EVENING HOURS WITH A MODERATE CHANCE
OF SEVERE THUNDERSTORMS ALONG WITH RAINFALL AMOUNTS AT 1 INCH NOT
UNCOMMON. STORMS MAY BE SUSTAINED INTO THE LATE 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/CEC
Local storm report, Jul 17, 6:10 PM MST, 15 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON ARIZONA
610 PM MST FRI JUL 17 1998

TIME(MST)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

605  PM    RYAN FIELD                AZ   WIND DAMAGE
07/17/98   PIMA                           94 MPH WIND GUST

600  PM    TUCSON                    AZ   WIND DAMAGE
07/17/98   PIMA                           MOBILE HOME ROOF DESTROYED

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 17, 5:41 PM MSTSevere Thunderstorm WarningTWCPima49 min
Jul 17, 7:25 PM MSTSevere Thunderstorm WarningTWCPima45 min
Jul 17, 7:33 PM MSTSevere Thunderstorm WarningTWCGreenlee47 min
Jul 17, 8:09 PM MSTSevere Thunderstorm WarningTWCPima61 min
Jul 17, 8:17 PM MSTSevere Thunderstorm WarningTWCGraham48 min
Jul 17, 11:14 PM MSTSevere Thunderstorm WarningTWCPinal46 min
Jul 18, 12:15 AM MSTSevere Thunderstorm WarningTWCPima90 min
Jul 18, 1:44 AM MSTSevere Thunderstorm WarningTWCPima46 min
Jul 18, 1:37 PM MSTSevere Thunderstorm WarningTWCSanta Cruz48 min
Jul 18, 2:08 PM MSTSevere Thunderstorm WarningTWCPima, Santa Cruz62 min
Jul 18, 2:44 PM MSTSevere Thunderstorm WarningTWCPima46 min
Jul 18, 3:25 PM MSTSevere Thunderstorm WarningTWCPima45 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.