Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 51, NWS Tucson, AZ

August 5, 1998Pima County, Santa Cruz County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Aug 5, 1998, 7:20 PM MST for Pima County, Santa Cruz County, Arizona. It was in force for 75 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 5, 1998, 7:20 PM MST (02:20 UTC)
Expired
Aug 5, 1998, 8:35 PM MST
In force
75 min
Issued by
NWS Tucson, AZ
Area
Whole counties

Counties Pima County, AZ, Santa Cruz County, AZ

The radar

The Tucson radar (KEMX), 66 km from the middle of the area, began a volume at 02:20 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, 2.3 hours before the alert went out and 56 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 1998-08-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.1000850700500300200100-30°-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 1998-08-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
7202 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
97 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.

971 
WUUS1 KTUS 060221 RRA
SVRTUS
AZC019-023-060335-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
720 PM MST WED AUG 5 1998

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

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

*  UNTIL 835 PM MST

...THIS REPLACES THE SEVERE THUNDERSTORM WARNING THAT IS NOW IN
EFFECT FOR EASTERN PIMA COUNTY...

...THIS WARNING DOES NOT INCLUDE THE TUCSON METRO AREA...


* AT 715 PM MST... DOPPLER RADAR INDICATED LINE OF SEVERE
THUNDERSTORMS FROM NORTHEAST SANTA CRUZ COUNTY WESTWARD TO TUBAC
THEN NORTHWEST ACROSS PIMA COUNTY TO THE THREE POINTS AREA THEN
NORTHWARD TO THE SILVER BELL MOUNTAINS. TOWNS IN THE PATH OF THE
LINE OF SEVERE THUNDERSTORMS ARE PATAGONIA...TUBAC...AMADO...AND
ARIVACA.

* THE SEVERE THUNDERSTORMS WILL BE NEAR...


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 Aug 5, 2:30 PM MST, 4 hours 50 minutes earlier.

Area forecast discussion, Aug 5, 2:30 PM MST, 4 hours 50 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST WED AUG 5 1998

SYNOPSIS...A SURGE ON MOISTURE FROM THE GULF OF CALIFORNIA HAS
MOVED INTO SOUTHERN ARIZONA THIS MORNING. NORTHERLY FLOW ALOFT WILL
BECOME EASTERLY BY FRIDAY FOR AN UPSWING IN THUNDERSTORM ACTIVITY
THROUGH THE END OF THE WORK WEEK.

DISCUSSION...GULF SURGE FROM THIS MORNING HAS WEAKENED AT YUMA BUT
SURFACE DEWPOINT VALUES HAVE NOT MIXED OUT AND REMAIN IN THE UPPER
50S TO LOWER 60S. WATER VAPOR PICTURE SHOWS THIS WEDGE OF MID-LVL
MOISTURE ACROSS THE WHITE MOUNTAINS. THIS AREA WAS THE FIRST TO
START WITH CONVECTION EARLIER THIS AFTERNOON AND ANSWERED ONE OF MY
QUESTIONS FROM MORNING DISCUSSION. AS OF 2PM/21Z THE BIGGEST STORMS
WERE JUST SOUTH OF THE BORDER IN NORTHERN MEXICO WHERE THE MOISTURE
IS MUCH RICHER. MODELS PROG WEAK SHORT WAVE TO MOVE SOUTH TO DOUGLAS
TONIGHT AND WITH COOL POOL ALOFT (-10C AIR) MAY HELP INITIATE
CONVECTION TONIGHT. WILL PUT HIGHEST POPS EAST AND SOUTH OF TUCSON.

UPPER HIGH CURRENTLY NW OF LAS VEGAS WILL DRIFT EAST TOWARD THE FOUR
CORNERS REGION BY FRIDAY. UPPER WINDS WILL BECOME NELY THURSDAY THAN
EASTERLY ON FRIDAY. LOW-LEVEL MOISTURE INTRUSION WILL CONTINUE WITH
TODAY ONLY SETTING CONDITIONS UP. CONCERN FOR THURSDAY IS POSSIBLE
SEVERE WEATHER EVENT WITH LAPSE RATES CONTINUING RATHER STEEP FOR
POSSIBLE MICROBURST ACTIVITY. SPC (STORMS PREDICTION CENTER) ALREADY
HAS PORTIONS OF SE AZ IN SLIGHT RISK CATEGORY. WILL HIGHLIGHT STRONG
WINDS IN AFTERNOON ZONE PACKAGE. TUS 2343. GLUECK

.TWC...NONE.

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 5, 5:24 PM MSTFlash Flood WarningTWCPima2 hr
Aug 5, 5:43 PM MSTSevere Thunderstorm WarningTWCPima62 min
Aug 5, 6:38 PM MSTFlash Flood WarningTWCPima52 min
Aug 5, 6:38 PM MSTSevere Thunderstorm WarningTWCPima52 min
Aug 5, 8:54 PM MSTFlash Flood WarningTWCPima96 min
Aug 5, 11:56 PM MSTSevere Thunderstorm WarningTWCPinal49 min
Aug 6, 2:44 AM MSTSevere Thunderstorm WarningTWCPima61 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.