Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 69, NWS Phoenix, AZ

August 15, 1998Pinal County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 15, 1998, 6:56 PM MST for Pinal County, Arizona. It was in force for 49 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 15, 1998, 6:56 PM MST (01:56 UTC)
Expired
Aug 15, 1998, 7:45 PM MST
In force
49 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

County Pinal County, AZ

The radar

The Phoenix radar (KIWA), 52 km from the middle of the area, began a volume at 01:59 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 15, 7:15 PM MSTThunderstorm Wind 55Coolidge, AZSeveral palo verde trees blown down. Some homes and businesses in Coolidge received minor damage due to the winds. One resident reported a stored row boat that blew about a quarter mile. Washes near Casa Grande, southwest of Coolidge, were reported running ab

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, 1.9 hours before the alert went out and 92 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 1998-08-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 485 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 1998-08-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 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
485 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
2881 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
34 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.

088 
WUUS1 KPHX 160158 RRA
SVRPHX
AZC021-160245-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
656 PM MST SAT AUG 15 1998


THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

*  SEVERE THUNDERSTORM WARNING FOR
   NORTHWESTERN AND NORTH CENTRAL PINAL COUNTY IN CENTRAL ARIZONA

*  UNTIL 745 PM MST

*  AT 650 MST DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
   5 MIKLES NORTHWEST COOLIDGE.  MOVEMENT WAS TO THE SOUTH
   SOUTHEAST AT 10 MPH.

*  SOME LOCATIONS AFFECTED INCLUDE
   COOLIDGE
   OLBERG
   SACATON

STRONG DAMAGING WINDS ARE LIKELY WITH THIS STORM.

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.

In the hours before

Special weather statement, Aug 15, 1:30 PM MST, 5 hours 26 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
130 PM MST SAT AUG 15 1998

AZZ020>028-161200-
MARICOPA-SOUTHERN GILA-NORTHWEST PINAL-LA PAZ-YUMA

...A MODERATE RISK OF HAZARDOUS WEATHER WILL EXIST LATER THIS
AFTERNOON AND THROUGH THE EVENING HOURS FOR MARICOPA...SOUTHERN
GILA...NORTHWEST PINAL...LA PAZ...AND YUMA COUNTIES...

THUNDERSTORMS HAVE STARTED TO DEVELOP OVER SOUTHWEST ARIZONA...AND
WILL CONTINUE TO DEVELOP THROUGH THE AFTERNOON AND EVENING HOURS. IN
ADDITION THUNDERSTORMS ALONG THE CENTRAL MOUNTAINS ARE EXPECTED TO
MOVE SOUTHWEST INTO THE LOWER DESERT AREAS LATE IN THE DAY. THE
ATMOSPHERE IS WET AND VERY UNSTABLE...A GOOD ENVIRONMENT FOR
PRODUCING THUNDERSTORMS ASSOCIATED WITH STRONG DAMAGING WINDS AND
HEAVY RAIN.

*********************************************************************

HAZARDOUS WEATHER REFERS TO ANY OF THE FOLLOWING...

1)   LOCALLY HEAVY RAINFALL RESULTING IN FLASH FLOODING OR FLOODING
2)   SAND OR DUST STORM REDUCING VISIBILITY TO 1/4 MILE OR LESS
3)   DAMAGING WINDS IN EXCESS OF 57 MPH
4)   HAIL 3/4 INCH OR LARGER IN DIAMETER

CHECK THE PHOENIX STATE FORECAST DISCUSSION FOR MORE INFORMATION.

JP
Special weather statement, Aug 15, 1:30 PM MST, 5 hours 26 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
130 PM MST SAT AUG 15 1998

AZZ020>028-161200-
MARICOPA-SOUTHERN GILA-NORTHWEST PINAL-LA PAZ-YUMA

...A MODERATE RISK OF HAZARDOUS WEATHER WILL EXIST LATER THIS
AFTERNOON AND THROUGH THE EVENING HOURS FOR MARICOPA...SOUTHERN
GILA...NORTHWEST PINAL...LA PAZ...AND YUMA COUNTIES...

THUNDERSTORMS HAVE STARTED TO DEVELOP OVER SOUTHWEST ARIZONA...AND
WILL CONTINUE TO DEVELOP THROUGH THE AFTERNOON AND EVENING HOURS. IN
ADDITION THUNDERSTORMS ALONG THE CENTRAL MOUNTAINS ARE EXPECTED TO
MOVE SOUTHWEST INTO THE LOWER DESERT AREAS LATE IN THE DAY. THE
ATMOSPHERE IS WET AND VERY UNSTABLE...A GOOD ENVIRONMENT FOR
PRODUCING THUNDERSTORMS ASSOCIATED WITH STRONG DAMAGING WINDS AND
HEAVY RAIN.

*********************************************************************

HAZARDOUS WEATHER REFERS TO ANY OF THE FOLLOWING...

1)   LOCALLY HEAVY RAINFALL RESULTING IN FLASH FLOODING OR FLOODING
2)   SAND OR DUST STORM REDUCING VISIBILITY TO 1/4 MILE OR LESS
3)   DAMAGING WINDS IN EXCESS OF 57 MPH
4)   HAIL 3/4 INCH OR LARGER IN DIAMETER

CHECK THE PHOENIX STATE FORECAST DISCUSSION FOR MORE INFORMATION.

JP

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 15, 5:19 PM MSTSevere Thunderstorm WarningPSRGila61 min
Aug 15, 7:29 PM MSTSevere Thunderstorm WarningPSRMaricopa66 min
Aug 15, 7:48 PM MSTSevere Thunderstorm WarningPSRMaricopa62 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.