Alert archive / California / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 9, NWS Hanford, CA

May 31, 2002Fresno County, California

NWS Hanford, CA issued this severe thunderstorm warning at May 31, 2002, 11:45 PM PDT for Fresno County, California. It was in force for 30 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
May 31, 2002, 11:45 PM PDT (06:45 UTC)
Expired
Jun 1, 2002, 12:15 AM PDT
In force
30 min
Issued by
NWS Hanford, CA
Area
Counties, with a storm outline in the text

County Fresno County, CA

What was reported inside it

TimeReportWhereRemark
Jun 1, 12:05 AM PDTThunderstorm Wind(Fch) Chandler Af, CA

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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Vandenberg AFB, CA (KVBG), launched 00:00Z, 6.8 hours before the alert went out and 231 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, Vandenberg AFB, CA at 00:00Z on 2002-06-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Vandenberg AFB, CA at 00:00Z on 2002-06-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1747 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
37 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.

659 
WUUS56 KHNX 010645
SVRHNX
CAC019-010715-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY CA
1144 PM PDT FRI MAY 31 2002

THE NATIONAL WEATHER SERVICE IN HANFORD CA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL FRESNO COUNTY IN CENTRAL CALIFORNIA
  THIS INCLUDES THE CITIES OF...FRESNO...CLOVIS

* UNTIL 1215 AM PDT

* AT 1137 PM PDT...DOPPLER RADAR SHOWED A SEVERE THUNDERSTORM OVER
  THE CITY OF FRESNO...NEARLY STATIONARY.

* THE SEVERE THUNDERSTORM WILL BE...
  NEAR THE CITY OF FRESNO THROUGH 1215 AM PDT

HAIL...INTENSE RAIN AND STRONG DAMAGING WINDS ARE LIKELY WITH THIS
STORM. TAKE COVER IN A SUBSTANTIAL SHELTER UNTIL THE STORM PASSES.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN HANFORD CA.

LAT...LON 3677 12009 3649 12000 3681 11960 3690 11969

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.

NWS Hanford, CA wrote its last area forecast discussion before this severe thunderstorm warning went out at May 31, 9:15 PM PDT, 2 hours 30 minutes earlier.

Area forecast discussion, May 31, 9:15 PM PDT, 2 hours 30 minutes before
INTERIOR CENTRAL CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
915 PM PDT FRI MAY 31 2002

UPPER LOW ALONG THE SOCAL COAST WAS TRACKING E-NE AT AROUND 20 KTS
THIS EVE...AND RUC APPEARS ON TRACK SHOWING LOW WEAKENING INTO AN
OPEN WAVE AND LIFTING ACROSS THE KERN MTNS/DESERTS LATE TONIGHT.
CAPE HAS BEGUN TO DECREASE OVER THE CWA WITH LOSS OF SURFACE
HEATING...AND DEEPER CONVECTION WAS DIMINISHING. GIVEN TRAJECTORY OF
LOW...WILL MAINTAIN POPS ACROSS MANY AREAS IN THE DISTRICT
OVERNIGHT. HOWEVER WILL MAKE SOME ADJUSTMENTS TO CLOUD COVER WORDING
GIVEN ROTATION OF COOLER TOPS AROUND CIRCULATION AND SOME DRIER AIR
MOVING INTO FAR SOUTHERN PORTIONS OF THE CWA.

OTHER ERN PAC TROUGH WAS MOVING INSIDE 130W THIS EVE AND ONSHORE
GRADS HAVE RESPONDED WITH SFO-SAC APPROACHING 4 MB AND MARINE LAYER
DEPTH NEAR 2K FEET. WILL THEREFORE ALSO MAKE SOME ADJUSTMENTS TO
WINDS IN SJ VALLEY AND KERN MTN/DESERT ZONES.

.HNX...NONE.

JSN

The office that day

Everything else NWS Hanford, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 31, 10:26 PM PDTSevere Thunderstorm WarningHNXFresno34 min
May 31, 10:54 PM PDTSevere Thunderstorm WarningHNXFresno36 min

Nearby

Severe Thunderstorm Warnings in California, 2002Every severe thunderstorm warning in 2002

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.