Alert archive / California / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 30, NWS Phoenix, AZ

August 12, 2003Imperial County, California

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 12, 2003, 5:39 PM PDT for Imperial County, California. It was in force for 36 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 12, 2003, 5:39 PM PDT (00:39 UTC)
Expired
Aug 12, 2003, 6:15 PM PDT
In force
36 min
Issued by
NWS Phoenix, AZ
Area
Counties, with a storm outline in the text

County Imperial County, CA

The radar

The San Diego radar (KNKX), 97 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.

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

San Diego, CA (KNKX), launched 00:00Z, 0.7 hours before the alert went out and 111 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, San Diego, CA at 00:00Z on 2003-08-13Temperature 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, San Diego, CA at 00:00Z on 2003-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 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
3545 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
4 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.

000 
WUUS55 KPSR 130039
SVRPSR
CAC025-130115-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
537 PM PDT TUE AUG 12 2003

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN IMPERIAL COUNTY IN SOUTHEAST CALIFORNIA

* UNTIL 615 PM PDT

* AT 535 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER OCOTILLO...MOVING NORTH AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE AFFECTING INTERSTATE 8 NEAR 
OCOTILLO AND HIGHWAY S2 NORTHWEST OF OCOTILLO.

DAMAGING MICROBURST WINDS ARE LIKELY WITH THIS STORM. VERY HEAVY RAIN
IS ALSO POSSIBLE. TAKE COVER IN A SUBSTANTIAL SHELTER UNTIL THE STORM
PASSES.

VERY LARGE HAIL IS POSSIBLE WITH THIS SEVERE THUNDERSTORM. IF YOU ARE
IN THE PATH OF THE STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A
SUBSTANTIAL SHELTER.

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

LAT...LON 3266 11608 3271 11587 3307 11593 3301 11608

$$

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 Phoenix, AZ wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 12, 4:50 PM PDT, 49 minutes earlier.

Area forecast discussion, Aug 12, 4:50 PM PDT, 49 minutes before
AZZ020>028-CAZ030>033-130545-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
450 PM MST TUE AUG 12 2003

.SYNOPSIS...
STRONG HIGH PRESSURE ALOFT RESPONSIBLE FOR THE RECORD HOT WEATHER
LATELY WILL SLOWLY SHIFT NORTHEAST TO THE NORTHERN GREAT PLAINS AND
THE UPPER MIDWEST THE NEXT FEW DAYS. AT THE SAME TIME...A LOW
PRESSURE SYSTEM FROM LOUISIANA WILL MOVE WEST INTO ARIZONA FRIDAY.
AS THE SYSTEM APPROACHES...CONDITIONS ARE ANTICIPATED TO BECOME
MORE FAVORABLE FOR STORM ACTIVITY BEGINNING WEDNESDAY IN
SOUTH-CENTRAL ARIZONA AND EXPANDING INTO SOUTHEAST CALIFORNIA
THURSDAY AND FRIDAY. IN ADDITION...TEMPERATURES WILL DECREASE
NOTICEABLY...MAINLY IN SOUTH-CENTRAL ARIZONA. OVER THE WEEKEND...THE
UPPER LOW WILL SHIFT NORTHEASTWARD ALLOWING A RIDGE OF HIGH PRESSURE
TO REDEVELOP BY EARLY NEXT WEEK. THIS WILL LEAD TO A GRADUAL WARMING
TREND WITH DECREASING CHANCES FOR STORMS.

.DISCUSSION...
ONLY ISOLATED STORMS OVER EASTERN PARTS OF ARIZONA SO FAR THIS
AFTERNOON. TONIGHT DOES NOT LOOK ANY MORE FAVORABLE FOR STORMS THAN
LAST NIGHT...THUS HAVE POPS CONFINED MAINLY TO THE SOUTH-CENTRAL
HIGHER TERRAIN. THINGS CHANGE BEGINNING WEDNESDAY. GIVEN THE
PREVIOUSLY DISCUSSED UNCERTAINTIES...HAVE MAINTAINED A CONSERVATIVE
APPROACH. MADE SOME MINOR ADJUSTMENTS TO PREVIOUS FORECAST PACKAGE
INCLUDING LESS OF A DOWN TREND IN TEMPS. BY SATURDAY...THE GFS STILL
HAS THE UPPER LOW CIRCULATION OVER ARIZONA...BUT THE STEERING FLOW
IS NOT ESPECIALLY FAVORABLE. NO SIGNIFICANT VERTICAL MOTIONS ARE
PROGGED EITHER. THUS WILL CALL FOR A TREND FOR DECREASING POPS IN
THE EXTENDED.

.PSR...NONE.
Hazardous weather outlook, Aug 12, 6:00 AM PDT, 11 hours 39 minutes before
AZZ020>028-CAZ030>033-130100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
600 AM MST TUE AUG 12 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHWEST AND
SOUTH-CENTRAL ARIZONA...AND SOUTHEAST CALIFORNIA.

.DAY ONE...TODAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. HOWEVER...
SCATTERED THUNDERSTORMS...SOME CAPABLE OF PRODUCING DAMAGING WIND...
HAIL...AND LOCALLY HEAVY RAIN...MAY OCCUR OVER SOUTH CENTRAL ARIZONA
WEDNESDAY EVENING...AND OVER SOUTHWEST AND SOUTH CENTRAL ARIZONA
THURSDAY AFTERNOON AND EVENING. DENSE BLOWING DUST MAY BE GENERATED
BY THUNDERSTORM OUTFLOW OVER THE SOUTH CENTRAL DESERT AREAS.

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.