Alert archive / California / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 86, NWS Phoenix, AZ

September 9, 1998Imperial County, Riverside County, California

NWS Phoenix, AZ issued this severe thunderstorm warning at Sep 9, 1998, 4:38 PM PDT for Imperial County, Riverside County, California. It was in force for 52 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
Sep 9, 1998, 4:38 PM PDT (23:38 UTC)
Expired
Sep 9, 1998, 5:30 PM PDT
In force
52 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

Counties Imperial County, CA, Riverside County, CA

The radar

The San Diego radar (KNKX), 137 km from the middle of the area, began a volume at 23:42 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

Yuma Intl Airpor, AZ (KYUM), launched 12:00Z, 11.6 hours before the alert went out and 130 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, Yuma Intl Airpor, AZ at 12:00Z on 1998-09-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 516 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Yuma Intl Airpor, AZ at 12:00Z on 1998-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 49 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
516 J/kg
Mixed-layer CIN
-210 J/kg
Mixed-layer LCL
2063 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
49 m²/s²
0-3 km storm-relative helicity
46 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 KPHX 092339 RRA
SVRPHX
CAC025-065-100030-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
438 PM MST (438 PM PDT) WED SEP 9 1998

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

*  SEVERE THUNDERSTORM WARNING FOR
   EXTREME NORTHEASTERN IMPERIAL COUNTY IN SOUTHEASTERN CALIFORNIA
   EASTERN RIVERSIDE COUNTY IN SOUTHEASTERN CALIFORNIA

*  UNTIL 530 PM PDT (530 PM MST)

*  AT 435 PM PDT DOPPLER RADAR INDICATED AN AREA OF SEVERE
   THUNDERSTORMS EXTENDING FROM PALO VERDE TO 10 MILES NORTHWEST OF
   BLYTHE. MOVEMENT WAS TO THE NORTHEAST AT 20 MPH.

*  SOME LOCATIONS AFFECTED INCLUDE
   MIDLAND
   INTERSTATE 10
   US 95
   BLYTHE

DAMAGING WINDS IN EXCESS OF 57 MPH...DENSE BLOWING DUST...AND
HEAVY RAIN ARE LIKELY WITH THIS STORM.

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 9, 3:52 PM PDTSevere Thunderstorm WarningPSRImperial38 min

Nearby

Severe Thunderstorm Warnings in California, 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.