Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 32, NWS Tucson, AZ

July 20, 1998Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Jul 20, 1998, 12:36 PM MST for Pima County, Arizona. It was in force for 64 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 20, 1998, 12:36 PM MST (19:36 UTC)
Expired: Jul 20, 1998, 1:40 PM MST
In force: 64 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 19:38 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 12:00Z, 7.6 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1677 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -24 m²/s²
0-3 km storm-relative helicity: 31 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.

825 
WUUS1 KTUS 201938 RRA
SVRTUS
AZC019-202040-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
1236 PM MST MON JUL 20 1998

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

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

* UNTIL 140 PM MST

* AT 1234 PM MST... DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
  ABOUT 10 MILES NORTH OF SASABE ALONG HIGHWAY 286. MOVEMENT WAS TO
  THE WEST AT 5 TO 10 MPH.

* FURTHER DEVELOPMENT IS LIKELY IN THIS AREA AND MAY AFFECT THE
  TOWNS OF SASABE...SAN MIGUEL AND SELLS.


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 20, 9:15 AM MST, 3 hours 21 minutes earlier.

Area forecast discussion, Jul 20, 9:15 AM MST, 3 hours 21 minutes before

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
915 AM MST MON JUL 20 1998

SYNOPSIS...A MOIST AND UNSTABLE ATMOSPHERE COMBINED WITH DAYTIME
HEATING WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS. SOME
OF THESE STORMS WILL PRODUCE HEAVY RAIN.

DISCUSSION...COMPLEX DECAYING IMMEDIATELY SOUTH OF DOUGLAS AND
SPREADING DEBRIS NORTH AND NORTHWEST WITH OUTFLOW PUSHING THROUGH
COCHISE AND SANTA CRUZ COUNTIES. ELSEWHERE DEBRIS CLOUD FROM
OVERNIGHT SLOWLY DISSIPATING. WE'LL NEED HEATING BUT ANOTHER ROUND
OF STORMS POSSIBLE TODAY (LIKELY NOT QUITE AS WIDESPREAD AS
YESTERDAY). 12Z TUS SOUNDING NOT COMPLETELY SPENT. SOME BOUNDARIES
STILL BOUNCING AROUND OUT THERE. HIGH CENTER TO THE NORTH LEAVES
FLOW STILL FAVORABLE FOR STORMS MOVING WESTWARD OFF OF EASTERN
MOUNTAINS AND SOME MID LEVEL DRYING IS EVIDENT ACROSS EAST CENTRAL
AREAS ON WATER VAPOR IMAGERY. BOTTOM LINE IS WE'LL HAVE TO KEEP AN
EYE ON THE RADAR ALL DAY...EVEN THE MORNING HOURS. THUNDERSTORM
COVERAGE SHOULD BE A LITTLE LESS...BUT RAINFALL SHOULD BE HEAVIER
WITH BETTER MOISTURE TO WORK WITH...FLASH FLOODING MAY BECOME A
CONCERN. LETTING A HEAVY SCATTERED THUNDERSTORM POP RIDE THROUGH
THIS EVENING. ~TUS 553. MEYER

.TWC...NONE.

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 19, 6:45 PM MST	Flash Flood Warning	TWC	Pima	2 hr
Jul 19, 6:52 PM MST	Flash Flood Warning	TWC	Pima	68 min
Jul 19, 6:52 PM MST	Severe Thunderstorm Warning	TWC	Pima	68 min
Jul 19, 7:58 PM MST	Severe Thunderstorm Warning	TWC	Pima	32 min

Nearby

Severe Thunderstorm Warnings in Arizona, 1998 Every 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.