Alert archive / California / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 3, NWS Hanford, CA

August 20, 2003Tulare County, California

NWS Hanford, CA issued this severe thunderstorm warning at Aug 20, 2003, 9:22 PM PDT for Tulare County, California. It was in force for 28 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 20, 2003, 9:22 PM PDT (04:22 UTC)
Expired
Aug 20, 2003, 9:50 PM PDT
In force
28 min
Issued by
NWS Hanford, CA
Area
Counties, with a storm outline in the text

County Tulare County, CA

The radar

The San Joaquin Valley radar (KHNX), 38 km from the middle of the area, began a volume at 04:24 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.

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, 4.4 hours before the alert went out and 202 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 2003-08-21Temperature 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 2003-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 163 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
898 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
163 m²/s²
0-3 km storm-relative helicity
166 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 
WUUS56 KHNX 210422
SVRHNX
CAC107-210450-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY CA
918 PM PDT WED AUG 20 2003

THE NATIONAL WEATHER SERVICE IN HANFORD CA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WEST CENTRAL TULARE COUNTY IN CENTRAL CALIFORNIA
  THIS INCLUDES THE CITY OF VISALIA

* UNTIL 950 PM PDT

* AT 909 PM PDT...DOPPLER RADAR SHOWED A SEVERE THUNDERSTORM OVER
  LINDSAY...OR ABOUT 11 MILES NORTHWEST OF PORTERVILLE...MOVING      
  NORTHWEST AT 15 MPH. STRONG AND GUSTY WINDS MAY REDUCE             
  VISIBILITIES TO LESS THAN 1/4 MILE AT TIMES.

* THE SEVERE THUNDERSTORM WILL BE...
NEAR VISALIA AT 940 PM PDT

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 3615 11935 3608 11899 3638 11910 3636 11933

$$
BINGHAM

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 Aug 20, 3:29 PM PDT, 5 hours 53 minutes earlier.

Area forecast discussion, Aug 20, 3:29 PM PDT, 5 hours 53 minutes before
INTERIOR CENTRAL CALIFORNIA FORECAST DISCUSSION...RETRANSMIT ONLY
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
200 PM PDT WED AUG 20 2003

KHNX 88D INDICATING CONVECTION BEGINNING NEAR THE SIERRA CREST. 18Z
MESO IS STRONGER WITH CAPES OVER THE MOUNTAINS AND KERN DESERTS THAN
PREVIOUS MODEL RUNS. INSTABILITY IS ALSO MORE PRONOUNCED WITH THE 18Z
MESO AS LI/S ACROSS THE MOUNTAINS AND KERN DESERTS ARE PROGGED TO BE
IN THE -1 TO -4 RANGE. THUNDERSTORMS HAVE ALREADY BEEN GOING ON FOR
THE PAST COUPLE OF HOURS OVER SOUTHERN SAN BERNARDINO COUNTY...AND WV
LOOP INDICATING ADDITIONAL MOISTURE IS ON IT/S WAY FROM THE
SOUTHEAST...SO WILL KEEP MENTION OF ISOLATED TO SCATTERED T-STORMS
ACROSS THE HIGHER ELEVATIONS FOR TONIGHT. THE OFFSHORE CUTOFF LOW
WHICH HAS BEEN OUR MAIN WEATHER FEATURE...HAS ACTUALLY BEEN
RETROGRADING TODAY...WHICH IS NOTHING NEW AS THE 12Z AND 18Z MESO...
AS WELL AS THE 12Z GFS...HAVE BEEN INDICATING THIS HAPPENING. THE LOW
IS EXPECTED TO MAKE AN EASTWARD TURN THURSDAY AS IT GETS SCOOPED UP
BY AN OPEN WAVE TROUGH WHICH WILL TURN THE UPPER FLOW OVER CENTRAL CA
TO THE SOUTH THEN TO THE SOUTHWEST. THE TIMING OF THIS TAKING PLACE
WILL BE CRITICAL IN TERMS OF CONVECTIVE DEVELOPMENT THURSDAY. AT THIS
TIME WITH CONFIDENCE LOW...WILL KEEP MENTION OF ISOLATED TO SCATTERED
POPS ACROSS THE ENTIRE CWFA THURSDAY...IN CASE OF A SLOWER TIMING.
TEMPERATURES THURSDAY WILL BE HIGHLY DEPENDENT ON THE AMOUNT OF CLOUD
COVER THAT SPREADS ACROSS THE AREA. COMPROMISED BETWEEN MET AND MAV
TEMPERATURE GUIDANCE. AS THE TROUGH SWINGS BY ACROSS NORCAL FRIDAY...
EXPECT SURFACE P-GRADS TO STRENGTHEN ENOUGH TO ALLOW FOR SOME MARINE
AIR TO SPILL INTO THE SAN JOAQUIN VALLEY. MEANWHILE...HIGHER
ELEVATIONS WILL BEGIN TO WARM UP AS SKIES CLEAR OUT. HIGH PRESSURE IS
EXPECTED TO BUILD INTO CENTRAL CA FROM THE DESERTS SOUTHWEST FRIDAY
NIGHT AND SATURDAY FOR MOSTLY CLEAR SKIES AND A DRYING TREND.

IN THE EXTENDED-FORECAST PERIOD...SUNDAY THROUGH WEDNESDAY...THE
MEDIUM-RANGE MODELS ARE IN GENERAL AGREEMENT WITH A WEAK SHORT-WAVE
TROUGH MOVING INTO THE PACIFIC NORTHWEST EARLY NEXT WEEK...ALTHOUGH
THERE ARE MINOR TIMING DIFFERENCES. THE TROUGH WILL HAVE LITTLE
IMPACT ON THE STRONG UPPER-LEVEL RIDGE OVER MUCH OF THE CONTINENTAL
UNITED STATES. 500-MB HEIGHTS ARE FORECAST TO REMAIN ABOVE 5880
METERS THROUGH THE PERIOD...WITH DRY WEATHER AND ABOVE-NORMAL HIGH
TEMPERATURES. BY MIDWEEK...THE GFS HAS A STRONGER SHORT-WAVE TROUGH
DROPPING OUT OF THE GULF OF ALASKA INTO THE PACIFIC NORTHWEST. THIS
TROUGH IS FORECAST TO WEAKEN THE RIDGE FOR THE LATTER HALF OF THE
WEEK.

THE GFS FORECASTS SOME HIGH-LEVEL MOISTURE TO WRAP AROUND THE RIDGE
INTO SOUTHERN CALIFORNIA BEGINNING TUESDAY...SO HAVE INCREASED CLOUD
COVER OVER THE MOUNTAINS AND DESERTS FOR SOME CIRRUS PER NEIGHBORING
OFFICES.

.HNX...NONE.

DS/SANGER
Hazardous weather outlook, Aug 20, 5:30 AM PDT, 15 hours 52 minutes before
CAZ089>099-211230-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HANFORD CA
530 AM PDT WED AUG 20 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE CENTRAL CALIFORNIA
INTERIOR.

.DAY ONE...TODAY.

THERE IS A CHANCE OF THUNDERSTORMS IN THE AFTERNOON AND A SLIGHT
CHANCE IN THE EVENING FOR THE SIERRA NEVADA FROM YOSEMITE TO KINGS
CANYON...FOR THE TULARE COUNTY MOUNTAINS...FOR THE KERN COUNTY
MOUNTAINS AND THE SOUTHEASTERN KERN COUNTY DESERT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

A SLIGHT CHANCE OF THUNDERSTORMS ARE FORECAST...FOR THURSDAY FOR THE
SAN JOAQUIN VALLEY, THE FRESNO COUNTY AND TULARE COUNTY FOOTHILLS,
THE KERN COUNTY MOUNTAINS AND THE KERN COUNTY DESERT...THERE IS A
CHANCE FOR THUNDERSTORMS...FOR THURSDAY FOR THE SIERRA NEVADA FROM
YOSEMITE TO KINGS CANYON, THE TULARE COUNTY MOUNTAINS AND THE
SOUTHEASTERN KERN COUNTY DESERT.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS TO THEIR LOCAL NATIONAL WEATHER SERVICE OFFICE.

Nearby

Severe Thunderstorm Warnings in California, 2003Every severe thunderstorm warning in 2003

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.