Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 76, NWS Phoenix, AZ

August 28, 1998Maricopa County, Pinal County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 28, 1998, 5:39 PM MST for Maricopa County, Pinal County, Arizona. It was in force for 31 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 28, 1998, 5:39 PM MST (00:39 UTC)
Expired
Aug 28, 1998, 6:10 PM MST
In force
31 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

Counties Maricopa County, AZ, Pinal County, AZ

The radar

The Phoenix radar (KIWA), 29 km from the middle of the area, began a volume at 00:38 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.

What was reported inside it

TimeReportWhereRemark
Aug 28, 6:09 PM MSTThunderstorm Wind 52Scottsdale, AZLarge area in the East Valley hit with high winds; 7 large trees knocked down in East Mesa and several power poles downed in Gilbert. Phoenix Sky Harbor Airport(PHX) recorded a peak gust of 53 mph at 1811 MST.

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, 0.7 hours before the alert went out and 143 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 1998-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 103 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 00:00Z on 1998-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 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
103 J/kg
Mixed-layer CIN
-247 J/kg
Mixed-layer LCL
2954 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
24 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.

701 
WUUS1 KPHX 290041 RRA
SVRPHX

AZC013-021-290110-
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
539 PM MST FRI AUG 28 1998


THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

*  SEVERE THUNDERSTORM WARNING FOR...
   EAST CENTRAL MARICOPA COUNTY IN CENTRAL ARIZONA
   NORTH CENTRAL PINAL COUNTY IN CENTRAL ARIZONA

*  UNTIL 610 PM MST

*  AT 540 PM MST DOPPLER RADAR INDICATED A SEVERE
   THUNDERSTORMS NEAR APACHE JUNCTION. MOVEMENT WAS TO
   THE WEST AT 10 MPH.

*  SOME LOCATIONS AFFECTED INCLUDE
    APACHE JUNCTION
    EAST MESA
    GILBERT

STRONG DAMAGING WINDS TO 65 MPH ARE LIKELY WITH THIS STORM AS WELL
AS DENSE BLOWING DUST AND HEAVY RAIN

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 28, 2:39 PM MST, 3 hours before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
245 PM MST SAT AUG 15 1998

AZZ023-024-028-291200-
EASTERN MARICOPA-SOUTHERN GILA-NORTHWEST PINAL

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

THUNDERSTORMS DEVELOPED OVER THE WHITE MOUNTAINS DURING THE LATE
MORNING AND EARLY AFTERNOON HOURS...AND HAVE STARTED TO MOVE
SOUTHWEST TOWARD THE DESERT AREAS. STRONG GUSTY WINDS HAVE BEEN
REPORTED WITH THE STORMS...AND HAIL COVERED THE GROUND EARLIER IN THE
AFTERNOON AT FORT APACHE.

ALTHOUGH LOCAL HEAVY RAINS MAY TAKE PLACE THE MAIN THREAT WILL BE
STRONG GUSTY WINDS...POSSIBLY TO OVER 50 MPH IN LOCAL GUSTS.

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

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 28, 2:45 PM MST, 2 hours 54 minutes before
HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE PHOENIX AZ
245 PM MST FRI AUG 28 1998

AZZ023-024-028-291200-
EASTERN MARICOPA-SOUTHERN GILA-NORTHWEST PINAL

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

THUNDERSTORMS DEVELOPED OVER THE WHITE MOUNTAINS DURING THE LATE
MORNING AND EARLY AFTERNOON HOURS...AND HAVE STARTED TO MOVE
SOUTHWEST TOWARD THE DESERT AREAS. STRONG GUSTY WINDS HAVE BEEN
REPORTED WITH THE STORMS...AND HAIL COVERED THE GROUND EARLIER IN THE
AFTERNOON AT FORT APACHE.

ALTHOUGH LOCAL HEAVY RAINS MAY TAKE PLACE THE MAIN THREAT WILL BE
STRONG GUSTY WINDS...POSSIBLY TO OVER 50 MPH IN LOCAL GUSTS.

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

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 28, 2:45 PM MST, 2 hours 54 minutes before
HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE PHOENIX AZ
245 PM MST FRI AUG 28 1998

AZZ023-024-028-291200-
EASTERN MARICOPA-SOUTHERN GILA-NORTHWEST PINAL

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

THUNDERSTORMS DEVELOPED OVER THE WHITE MOUNTAINS DURING THE LATE
MORNING AND EARLY AFTERNOON HOURS...AND HAVE STARTED TO MOVE
SOUTHWEST TOWARD THE DESERT AREAS. STRONG GUSTY WINDS HAVE BEEN
REPORTED WITH THE STORMS...AND HAIL COVERED THE GROUND EARLIER IN THE
AFTERNOON AT FORT APACHE.

ALTHOUGH LOCAL HEAVY RAINS MAY TAKE PLACE THE MAIN THREAT WILL BE
STRONG GUSTY WINDS...POSSIBLY TO OVER 50 MPH IN LOCAL GUSTS.

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

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 28, 6:04 PM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal86 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.