Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 13, NWS Phoenix, AZ

July 17, 1998Gila County, Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 17, 1998, 4:14 PM MST for Gila County, Maricopa County, Arizona. It was in force for 66 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, 4:14 PM MST (23:14 UTC)
Expired
Jul 17, 1998, 5:20 PM MST
In force
66 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

Counties Gila County, AZ, Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 32 km from the middle of the area, began a volume at 23:17 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, 11.2 hours before the alert went out and 171 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 12:00Z on 1998-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 39 joules per kilogram.LCLLFCEL10008507005003002001001 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 12:00Z on 1998-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -50 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
39 J/kg
Mixed-layer CIN
-292 J/kg
Mixed-layer LCL
2735 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
-50 m²/s²
0-3 km storm-relative helicity
60 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

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

770 
WUUS1 KPHX 172316 RRA
SVRPHX
AZC007-013-180020-

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


THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

*  SEVERE THUNDERSTORM WARNING FOR
   SOUTHWESTERN GILA COUNTY IN CENTRAL ARIZONA
   NORTHEASTERN MARICOPA COUNTY IN CENTRAL ARIZONA

*  UNTIL 520 PM MST

*  AT 410 PM MST DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
   12 MILES NORTHEAST OF SUNFLOWER.  MOVEMENT WAS TO THE SOUTHWEST AT
   20 MPH.

*  SOME LOCATIONS AFFECTED INCLUDE
   ROOSEVELT LAKE
   SUNFLOWER
   PUNKIN CENTER
   BEELINE HIGHWAY SOUTH OF MT. ORD

STRONG DAMAGING WINDS IN EXCESS OF 57 MPH ARE LIKELY WITH THIS STORM
...AS WELL AS HAIL UP TO ONE INCH IN DIAMETER.

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, Jul 17, 1:30 PM MST, 2 hours 44 minutes before
AZZ020>028-CAZ030>033-181200-
MARICOPA-SOUTHERN GILA-NORTHWEST PINAL-YUMA-LA PAZ-IMPERIAL-
CENTRAL/EASTERN RIVERSIDE-JOSHUA TREE NATIONAL PARK-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
130 PM MST FRI JUL 17 1998

...MODERATE RISK FOR HAZARDOUS WEATHER OVER SOUTHWEST AND SOUTH-
CENTRAL ARIZONA TONIGHT...

THE PRIMARY WEATHER THREAT TONIGHT WILL BE STRONG GUSTY WINDS...
POSSIBLY TO AROUND 60 MPH WITH A FEW OF THE EXPECTED THUNDERSTORMS.
AND BLOWING DUST ON THE DESERT MAY BRIEFLY RESTRICT VISIBILITY TO
LESS THAN A QUARTER MILE.
*********************************************************************
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.
Special weather statement, Jul 17, 1:30 PM MST, 2 hours 44 minutes before
AZZ020>028-CAZ030>033-181200-
MARICOPA-SOUTHERN GILA-NORTHWEST PINAL-YUMA-LA PAZ-IMPERIAL-
CENTRAL/EASTERN RIVERSIDE-JOSHUA TREE NATIONAL PARK-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
130 PM MST FRI JUL 17 1998

...MODERATE RISK FOR HAZARDOUS WEATHER OVER SOUTHWEST AND SOUTH-
CENTRAL ARIZONA TONIGHT...

THE PRIMARY WEATHER THREAT TONIGHT WILL BE STRONG GUSTY WINDS...
POSSIBLY TO AROUND 60 MPH WITH A FEW OF THE EXPECTED THUNDERSTORMS.
AND BLOWING DUST ON THE DESERT MAY BRIEFLY RESTRICT VISIBILITY TO
LESS THAN A QUARTER MILE.
*********************************************************************
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.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 16, 7:45 PM MSTSevere Thunderstorm WarningPSRPinal60 min
Jul 16, 8:09 PM MSTSevere Thunderstorm WarningPSRPinal51 min
Jul 17, 4:45 PM MSTSevere Thunderstorm WarningPSRMaricopa75 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.