Alert archive / California / Severe Thunderstorm Warnings in 2003
Severe Thunderstorm Warning 45, NWS Phoenix, AZ
NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 20, 2003, 3:21 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 20, 2003, 3:21 PM PDT (22:21 UTC)
- Expired
- Aug 20, 2003, 4:15 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 San Diego radar (KNKX), 151 km from the middle of the area, began a volume at 22:21 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
Yuma Intl Airpor, AZ (KYUM), launched 12:00Z, 10.4 hours before the alert went out and 160 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.
- Mixed-layer CAPE
- 4 J/kg
- Mixed-layer CIN
- -263 J/kg
- Mixed-layer LCL
- 1937 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 44 m²/s²
- 0-3 km storm-relative helicity
- 33 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 WUUS55 KPSR 202221 SVRPSR CAC065-202315- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE PHOENIX AZ 320 PM PDT WED AUG 20 2003 THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... CENTRAL RIVERSIDE COUNTY IN SOUTHEAST CALIFORNIA * UNTIL 415 PM PDT * AT 320 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 11 MILES NORTHEAST OF CHIRIACO SUMMIT...OR ABOUT 8 MILES WEST OF DESERT CENTER. THE STORM IS MOVING SLOWLY TO THE NORTH. * THE SEVERE THUNDERSTORM WILL BE NEAR...INTERSTATE 10...FROM DESERT CENTER NORTHWESTWARD INTO THE SOUTHERN PORTION OF JOSHUA TREE NATIONAL PARK. DAMAGING MICROBURST WINDS ARE LIKELY WITH THIS STORM. VERY HEAVY RAIN IS ALSO POSSIBLE. 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. LAT...LON 3360 11557 3377 11539 3393 11600 3374 11616 $$
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 20, 3:15 PM PDT, 6 minutes earlier.
Area forecast discussion, Aug 20, 3:15 PM PDT, 6 minutes before
AZZ020>028-CAZ030>033-210545-
SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
WEATHER SERVICE PHOENIX AZ
315 PM MST WED AUG 20 2003
.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTH ACROSS SOUTHERN CALIFORNIA
AND SOUTHWEST ARIZONA THIS EVENING. THIS MEANS SCATTERED SHOWERS AND
THUNDERSTORMS MAINLY OVER SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA
WITH LOCALLY HEAVY RAIN THERE THIS AFTERNOON THROUGH THIS EVENING.
HIGH PRESSURE ALOFT OVER NEW MEXICO WILL MOVE NORTH TO COLORADO BY
THURSDAY...AND STAY TO THE NORTH THROUGH MONDAY. THIS MEANS A MOIST
FLOW OF AIR FROM THE EAST WITH A CHANCE OF AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS THROUGH EARLY NEXT WEEK.
.DISCUSSION...
A FLASH FLOOD WATCH IS IN EFFECT FOR SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA UNTIL 9 PM MST OR 9 PM PDT THIS EVENING. A MOIST AND
UNSTABLE AIRMASS...AND A WEAK LOW PRESSURE SYSTEM MOVING NORTH OVER
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA ARE RESPONSIBLE FOR THE
FLASH FLOOD PRODUCING STORMS. AS A RESULT...TEMPERATURES WERE MUCH
COOLER BY MID AFTERNOON IN PORTIONS OF THOSE AREAS. MEANWHILE...IT
WAS MUCH WARMER IN THE GREATER PHOENIX AREA TODAY DUE TO SUNNY SKIES
COMPARED WITH MOSTLY CLOUDY SKIES YESTERDAY. THERE IS STILL A CHANCE
OF SHOWERS AND THUNDERSTORMS DEVELOPING IN WESTERN MARICOPA COUNTY
WITH A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS DEVELOPING FROM
THE SOUTH IN THE REST OF THE SOUTH-CENTRAL ARIZONA DESERT AREAS
INCLUDING PHOENIX THIS EVENING. HIGH PRESSURE ALOFT CENTERED OVER
NEW MEXICO WILL MOVE NORTH TO COLORADO BY THURSDAY...AND STAY TO THE
NORTH THROUGH MONDAY. THIS MEANS A MOIST FLOW OF AIR FROM THE EAST
WITH A CHANCE OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
THROUGH EARLY NEXT WEEK. WEAK LOW PRESSURE SYSTEMS IN THIS FLOW ARE
EXPECTED TO ENHANCE THE CHANCE OF SHOWERS AND THUNDERSTORMS AT TIMES
MAINLY IN THE ARIZONA PORTION WHICH IS EXPECTED TO BE THE CASE
THURSDAY NIGHT INTO FRIDAY MORNING.
ELLIS
.PSR...FLASH FLOOD WATCH FOR SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA UNTIL 9 PM MST OR 9 PM PDT...INCLUDING AZ ZONES
20...21...25...AND 26...AND CA ZONES 30...31...32...AND 33.Hazardous weather outlook, Aug 20, 12:40 PM PDT, 2 hours 41 minutes before
AZZ020>028-CAZ030>033-210100- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PHOENIX AZ 1240 PM MST WED AUG 20 2003 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHWEST AND SOUTH-CENTRAL ARIZONA...AND SOUTHEAST CALIFORNIA. .DAY ONE...TODAY A FLASH FLOOD WATCH IS IN EFFECT FOR SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA UNTIL 9 PM THIS EVENING. PLEASE SEE THE FLASH FLOOD WATCH PRODUCT PHXHWOPSR OR WMO HEADER WGUS65 KPSR FFAPSR. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .INSTRUCTIONS TO SPOTTERS... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. ELLIS
The office that day
Everything else NWS Phoenix, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 4:24 PM PDT | Severe Thunderstorm Warning | PSR | Riverside | 51 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.