Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 56, NWS Phoenix, AZ

August 12, 1998Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 12, 1998, 6:10 PM MST for Maricopa County, Arizona. It was in force for 45 min. 2 reports 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 12, 1998, 6:10 PM MST (01:10 UTC)
Expired
Aug 12, 1998, 6:55 PM MST
In force
45 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 77 km from the middle of the area, began a volume at 01:13 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 12, 6:12 PM MSTThunderstorm Wind 65Wickenburg, AZA strong to severe complex of storms formed northeast of Wickenburg and moved to the southwest and intensified. The storms produced severe damage to at least 2 aircraft at the Wickenburg airport. About 6 power poles were blown down, and evaporative coolers wer
Aug 12, 6:30 PM MSTThunderstorm Wind 50Tempe, AZLarge tree limbs downed by winds near Broadway and Rural. Numerous streets in Tempe flooded.

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, 1.2 hours before the alert went out and 198 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 1998-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 245 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 1998-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -11 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
245 J/kg
Mixed-layer CIN
-38 J/kg
Mixed-layer LCL
2671 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
-11 m²/s²
0-3 km storm-relative helicity
-3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 12, 4:00 PM MST, 2 hours 10 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
400 PM MST WED AUG 12 1998

AZZ021>023-026>028-131200-
MARICOPA-NORTHWEST PINAL-LA PAZ-YUMA-

...MODERATE TO HIGH RISK OF HAZARDOUS WEATHER LATE THIS AFTERNOON
AND EARLY TONIGHT IN LA PAZ...YUMA...MARICOPA...AND NORTHWEST
PINAL COUNTIES.

A LINE OF VERY STRONG THUNDERSTORMS DEVELOPING ALONG THE LENGTH OF
THE MOGOLLON RIM WERE MOVING SOUTHWEST TOWARD THE LOWER DESERTS.
THE ATMOSPHERE OVER THE SOUTH CENTRAL AND SOUTHWEST DESERTS IS
VERY UNSTABLE. THUNDERSTORMS MOVING INTO THE DESERTS THIS EVENING
HAVE THE POTENTIAL FOR PRODUCING VERY STRONG POSSIBLY DAMAGING
WINDS...INTENSE LIGHTNING...AND VERY HEAVY RAIN.

THE MODERATE TO HIGH RISK OF HAZARDOUS WEATHER INCLUDES ALL OF
THE GREATER PHOENIX AREA... FLORENCE...CASA GRANDE...GILA BEND...
WICKENBURG...AND OTHER LOCATIONS IN YUMA AND LA PAZ COUNTIES.

STAY TUNED TO THE LATEST FORECASTS AND UPDATES CONCERNING THIS
APPROACHING WEATHER.  TAKE SHELTER IMMEDIATELY IF THREATENING
WEATHER APPROACHES.

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

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.

HV
Special weather statement, Aug 12, 4:00 PM MST, 2 hours 10 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
400 PM MST WED AUG 12 1998

AZZ021>023-026>028-131200-
MARICOPA-NORTHWEST PINAL-LA PAZ-YUMA-

...MODERATE TO HIGH RISK OF HAZARDOUS WEATHER LATE THIS AFTERNOON
AND EARLY TONIGHT IN LA PAZ...YUMA...MARICOPA...AND NORTHWEST
PINAL COUNTIES.

A LINE OF VERY STRONG THUNDERSTORMS DEVELOPING ALONG THE LENGTH OF
THE MOGOLLON RIM WERE MOVING SOUTHWEST TOWARD THE LOWER DESERTS.
THE ATMOSPHERE OVER THE SOUTH CENTRAL AND SOUTHWEST DESERTS IS
VERY UNSTABLE. THUNDERSTORMS MOVING INTO THE DESERTS THIS EVENING
HAVE THE POTENTIAL FOR PRODUCING VERY STRONG POSSIBLY DAMAGING
WINDS...INTENSE LIGHTNING...AND VERY HEAVY RAIN.

THE MODERATE TO HIGH RISK OF HAZARDOUS WEATHER INCLUDES ALL OF
THE GREATER PHOENIX AREA... FLORENCE...CASA GRANDE...GILA BEND...
WICKENBURG...AND OTHER LOCATIONS IN YUMA AND LA PAZ COUNTIES.

STAY TUNED TO THE LATEST FORECASTS AND UPDATES CONCERNING THIS
APPROACHING WEATHER.  TAKE SHELTER IMMEDIATELY IF THREATENING
WEATHER APPROACHES.

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

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.

HV

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 6:07 PM MSTSevere Thunderstorm WarningPSRMaricopa48 min
Aug 12, 6:15 PM MSTFlash Flood WarningPSRMaricopa65 min
Aug 12, 6:55 PM MSTSevere Thunderstorm WarningPSRMaricopa50 min
Aug 12, 7:16 PM MSTFlash Flood WarningPSRMaricopa94 min
Aug 12, 7:42 PM MSTSevere Thunderstorm WarningPSRMaricopa48 min
Aug 12, 8:29 PM MSTSevere Thunderstorm WarningPSRLa Paz46 min
Aug 12, 10:43 PM MSTSevere Thunderstorm WarningPSRYuma92 min
Aug 13, 4:12 PM MSTSevere Thunderstorm WarningPSRMaricopa48 min
Aug 12, 9:34 PM MSTSevere Thunderstorm WarningPSRRiverside46 min
Aug 12, 10:22 PM MSTSevere Thunderstorm WarningPSRImperial, Riverside63 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.