Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 40, NWS Tucson, AZ

July 28, 1998Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Jul 28, 1998, 7:22 PM MST for Pima County, Arizona. It was in force for 63 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 28, 1998, 7:22 PM MST (02:22 UTC)
Expired: Jul 28, 1998, 8:25 PM MST
In force: 63 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 02:22 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, 2.4 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-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: 155 J/kg
Mixed-layer CIN: -46 J/kg
Mixed-layer LCL: 3328 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: -3 m²/s²
0-3 km storm-relative helicity: -15 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.

000 
TTAA00 KTUS 290223 RRA
SVRTUS
AZC019-290325-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
722 PM MST TUE JUL 28 1998

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

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

* UNTIL 825 PM MST

* AT 720 PM MST...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 8
  MILES SOUTH SOUTHEAST OF SELLS MOVING SOUTH SOUTHEAST AT 10 MPH.

* THIS STORM IS EXPECTED TO AFFECT THE SAN MIGUEL AREA BY 810 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 28, 2:30 PM MST, 4 hours 52 minutes earlier.

Area forecast discussion, Jul 28, 2:30 PM MST, 4 hours 52 minutes before

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST TUE JUL 28 1998

SYNOPSIS...MOISTURE MOVING BACK INTO SOUTHEAST ARIZONA WILL LEAD TO
A STRONG INCREASE IN THUNDERSTORM ACTIVITY THROUGH THE WEEK.

DISCUSSION...TWO FACTORS LEADING TO A BIG UPSWING IN THUNDERSTORM
ACTIVITY NEXT 24-36 HOURS. FIRST IS EASTERLY WAVE MOVING ACROSS
NORTHERN MEXICO JUST SOUTH OF DOUGALS. THIS HAS PUSHED MOISTURE
BOUNDRY JUST TO THE WEST OF TUCSON. THIS REFLECTED IN SURFACE DEW
POINTS IN THE UPPER 50S ACROSS THE AREA. SECOND IS GULF SURGE TAKING
PLACE AT THE MOMENT. ITS ONLY MINOR SO FAR BUT EXPECT IT TO INCREASE
NEXT 12 HOURS OR SO DUE TO BIG COMPLEX MOVING UP THE GULF AND LOW
LEVEL PRESSURE GRADIENT FAVORS MOISTURE SURGE. WILL GO WITH
SCATTERED COVERAGE EAST TO ISOLATED FAR WEST TONIGHT AND THEN
GENERALLY SCATTERED COVERAGE ALL AREAS WEDNESDAY AND THURSDAY. WITH
EASTERLY WAVE IN THE PICTURE NEXT 24 HOURS WILL NOT CONFINE
THUNDERSTORMS TO JUST THE AFTERNOON AND EVENING HOURS. NO CHANGE
SEEN IN THE EXTENDED PERIOD.

TUS 4444. COLLINS

.TWC...NONE

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 28, 5:53 PM MST	Severe Thunderstorm Warning	TWC	Cochise	47 min
Jul 28, 6:30 PM MST	Flash Flood Warning	TWC	Cochise	65 min
Jul 28, 6:38 PM MST	Severe Thunderstorm Warning	TWC	Cochise	47 min
Jul 29, 4:13 PM MST	Severe Thunderstorm Warning	TWC	Cochise	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.