Alert archive / California / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 59, NWS Phoenix, AZ

August 26, 2003Riverside County, California

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 26, 2003, 4:06 PM PDT for Riverside County, California. It was in force for 54 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 26, 2003, 4:06 PM PDT (23:06 UTC)
Expired
Aug 26, 2003, 5:00 PM PDT
In force
54 min
Issued by
NWS Phoenix, AZ
Area
Counties, with a storm outline in the text

County Riverside County, CA

The radar

The Yuma radar (KYUX), 166 km from the middle of the area, began a volume at 23:05 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 26, 1:55 PM PDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Yuma Intl Airpor, AZ (KYUM), launched 12:00Z, 11.1 hours before the alert went out and 154 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 2003-08-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 111 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, Yuma Intl Airpor, AZ at 12:00Z on 2003-08-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -18 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
111 J/kg
Mixed-layer CIN
-261 J/kg
Mixed-layer LCL
2175 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
-18 m²/s²
0-3 km storm-relative helicity
22 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS55 KPSR 262306
SVRPSR
CAC065-270000-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
403 PM PDT TUE AUG 26 2003

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL RIVERSIDE COUNTY IN SOUTHEAST CALIFORNIA

* UNTIL 500 PM PDT

* AT 400 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR             
  INDICATED SEVERE THUNDERSTORM 7 MILES WEST OF DESERT               
  CENTER...MOVING SLOWLY TO THE NORTHEAST. THE EAGLE MOUNTAIN        
  AREA...AS WELL AS DESERT CENTER...MAY BE AFFECTED BY THIS STORM.

DAMAGING MICROBURST WINDS IN EXCESS OF 60 MPH...LARGE HAIL...AND 
VERY HEAVY RAIN 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 PHOENIX.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 700 PM PDT
TUESDAY EVENING FOR WEST CENTRAL ARIZONA AND SOUTHEAST CALIFORNIA.

LAT...LON 3385 11570 3364 11566 3368 11531 3390 11536

$$

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 26, 3:15 PM PDT, 51 minutes earlier.

Area forecast discussion, Aug 26, 3:15 PM PDT, 51 minutes before
AZZ020>028-CAZ030>033-270545-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
WEATHER SERVICE PHOENIX AZ
315 PM MST TUE AUG 26 2003

.SYNOPSIS...
A FLOW ALOFT FROM THE EAST THEN SOUTH IS EXPECTED TONIGHT THROUGH
WEDNESDAY. IN ADDITION...MOISTURE FROM FORMER HURRICANE IGNACIO WILL
CONTINUE INCREASING TONIGHT THROUGH WEDNESDAY. THIS MEANS AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS TONIGHT...WITH SOME
HEAVY RAIN POSSIBLE AND COOLER WEATHER THROUGH WEDNESDAY. HIGH
PRESSURE ALOFT FROM THE PACIFIC IS EXPECTED TO BRING A REDUCTION IN
THUNDERSTORMS BY FRIDAY.

.DISCUSSION...
A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA UNTIL 7 PM MST AND PDT OR 0200 GMT. A FLASH
FLOOD WATCH IS IN EFFECT FOR SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA UNTIL 10 PM MST AND PDT OR 0500 GMT THIS EVENING...AND
FOR SOUTH-CENTRAL ARIZONA INCLUDING THE GREATER PHOENIX AREA THROUGH
WEDNESDAY. MOISTURE FROM FORMER HURRICANE IGNACIO IS INCREASING AND
THERE WAS EVEN A STRONG GULF SURGE BELOW 5 THOUSAND FEET INTO YUMA
THIS MORNING WITH WIND GUSTING TO 35 MPH AND VISIBILITY DOWN TO 4
MILES IN BLOWING DUST AROUND 5 AND 6 AM MST. THE AIRMASS IS GETTING
TO THE POINT WHERE IT IS HOLDING NEARLY AS MUCH MOISTURE AS IT EVER
HOLDS IN SOUTHEAST CALIFORNIA...SOUTHWEST AND SOUTH-CENTRAL ARIZONA.
EXPECT AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS TONIGHT
WITH SOME HEAVY RAIN...AND COOLER WEATHER THROUGH WEDNESDAY WITH A
HIGH FLASH FLOOD POTENTIAL. THUS...THE REASON FOR THE FLASH
FLOOD WATCHES. HIGH PRESSURE ALOFT FROM THE PACIFIC IS EXPECTED TO
BRING A REDUCTION IN THUNDERSTORMS BY FRIDAY. THEN...THE WEAK LOW
PRESSURE SYSTEM ASSOCIATED WITH IGNACIO IS EXPECTED TO MOVE NORTH
CONTINUING A CHANCE AND SHOWERS AND THUNDERSTORMS MAINLY OVER THE
HIGHER TERRAIN THROUGH THIS COMING LABOR DAY WEEKEND...

.PSR...FLASH FLOOD WATCH FOR SOUTHWEST ARIZONA AND SOUTHEAST
       CALIFORNIA ZONES 20...21...25...26...30...31...32...AND 33
       YUMA COUNTY...LA PAZ COUNTY...IMPERIAL COUNTY AND EASTERN
       RIVERSIDE COUNTY INCLUDING ALL OF JOSHUA TREE NATIONAL PARK
       10 PM MST THIS EVENING OR 27/0500 GMT....AND FOR SOUTH-CENTRAL
       ARIZONA ZONES 22...23...24...27...AND 28 MARICOPA COUNTY...
       NORTH CENTRAL AND NORTHWEST PINAL COUNTY AND SOUTHERN GILA
       COUNTY THROUGH WEDNESDAY.
       SEVERE THUNDERSTORM WATCH FOR SOUTHWEST ARIZONA AND
       SOUTHEAST CALIFORNIA UNTIL 7 PM MST AND PDT OR 0200 GMT
       THIS EVENING.

ELLIS
Hazardous weather outlook, Aug 26, 6:00 AM PDT, 10 hours 6 minutes before
AZZ020>028-CAZ030>033-270100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
600 AM MST TUE AUG 26 2003

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

.DAY ONE...TODAY

THE AIRMASS OVER ARIZONA AND SOUTHEAST CALIFORNIA REMAINS VERY
MOIST AND UNSTABLE...AND ADDITIONAL MOISTURE IS EXPECTED TO MOVE
INTO ARIZONA FROM FORMER HURRICANE IGNACIO. THUS SCATTERED
THUNDERSTORMS ARE FORECAST TO DEVELOP TODAY...MAINLY IN THE LATE
AFTERNOON AND EVENING HOURS. HEAVY RAIN IS POSSIBLE WITH ANY
THUNDERSTORM...AS WELL AS SOME BLOWING DUST AND STRONG GUSTY WINDS.
HEAVY RAIN COULD LEAD TO FLOODING OF ROADS...WASHES AND OTHER LOW
SPOTS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THERE WILL BE AN INCREASED THREAT FOR SHOWERS AND THUNDERSTORMS WITH
HEAVY RAIN WEDNESDAY AND WEDNESDAY NIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...AS MOISTURE FROM IGNACIO CONTINUES TO SPREAD
INTO ARIZONA. STAY AWAY FROM FLOODED AREAS INCLUDING ROADWAYS AND
WASHES...AND BE PREPARED TO MOVE TO HIGHER GROUND SHOULD A WARNING
BE ISSUED.

.INSTRUCTIONS TO SPOTTERS...
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

BRECKENRIDGE

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 26, 3:03 PM PDTFlash Flood WarningPSRRiverside, San Bernardino117 min

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.