Flash Flood in California, August 26, 2003

Name: Flash Flood in California, August 26, 2003
Start: 2003-08-26T13:31
End: 2003-08-26T14:00
Location: California

August 26, 2003 · NWS SGX · 1 event in 1 county or zone

Heavy rain caused one foot of water across Highway 78 near Yaqui Pass road and also on Montezuma road (S22), and mud slides 4 feet deep across San Felipe road (S2) at mile marker 8.

Where it happened

Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

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Floods
Wind
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Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
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The toll

Deaths: 0
Injuries: 0
Property damage: $50,000
Crop damage: None recorded
Events: 1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS SGX wrote it up.

Heavy rain caused one foot of water across Highway 78 near Yaqui Pass road and also on Montezuma road (S22), and mud slides 4 feet deep across San Felipe road (S2) at mile marker 8. Two vehicles were trapped

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS San Diego, CA wrote its last area forecast discussion before the first event at Aug 26, 1:00 PM PST, 31 minutes earlier.

Area forecast discussion, Aug 26, 1:00 PM PST, 31 minutes before

EXTREME SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CALIFORNIA
200 PM PDT TUE AUG 26 2003

.SYNOPSIS...MONSOONAL MOISTURE WILL BRING SCATTERED THUNDERSTORMS TO
THE MOUNTAINS AND DESERTS AGAIN TOMORROW AND THURSDAY. OTHERWISE...
FAIR AND HUMID...WITH AREAS OF LATE NIGHT AND MORNING LOW CLOUDS AND
FOG NEAR THE COAST. HIGH PRESSURE ALOFT MAY DECREASE THUNDERSTORM
ACTIVITY A BIT LATE IN THE WEEK...BUT WE WILL REMAIN CLOSE ENOUGH TO
THE MOISTURE TO KEEP A THREAT EACH AFTERNOON IN THE MOUNTAINS INTO
THE HOLIDAY WEEKEND.

DISCUSSION...STRONG THUNDERSTORMS DEVELOPED AROUND NOON OVER THE SAN
BERNARDINO MOUNTAINS AND NOW ARE OCCURRING OVER ALL MOUNTAIN AREAS.
MIRAMAR INVERSION BASE FROM 12Z A BIT HIGHER THAN YESTERDAY WITH
SIMILAR ONSHORE GRADIENTS TO THE LOWER DESERTS. STRATUS QUICKLY
DISSIPATED THIS AM LEAVING SUNNY SKIES AT THE COAST. A SEVERE
THUNDERSTORM WATCH HAS BEEN ISSUED BY SPC AND INCLUDES ALL MTN AND
DESERT AREAS DUE TO VERY HIGH MOISTURE CONTENT AND INSTABILITY IN
THE ATMOSPHERE. VERY HEAVY RAINFALL RATES HAVE BEEN OBSERVED WITH
THE RADAR HYBRID REFLECTIVITY PRODUCTS THIS AFTERNOON EVEN THOUGH
ALERT GAGES AND SPOTTER REPORTS HAVE NOT BEEN EXCESSIVE UP TO NOW.

AVN MODEL SHOWS A CONTINUATION OF WEAK FLOW ALOFT AND SOME MONSOONAL
MOISTURE THROUGH THURSDAY...FOLLOWED BY BUILDING HIGH PRESSURE ALOFT
JUST OFF THE COAST ON FRI. THIS BRINGS IN INCREASINGLY DRY NW FLOW
AS WE HEAD INTO THE WEEKEND. THERE SEEMS TO BE SOME SUPPORT TO THIS
SOLUTION WITH THE UK MODEL. REMNANTS OF IGNACIO FCST TO REMAIN
TRAPPED NEAR THE BAJA SPUR BUT COULD MAKE A SLOW ADVANCE ON SW CA IF
THE HIGH WEAKENS ENOUGH OR SLIPS BACK TO THE EAST. THE JURY IS NOT
IN...AND THE VERDICT MAY TAKE SOME TIME AND A FEW MORE MODEL RUNS.
IT WILL BE DIFFICULT TO REMOVE THE CHANCE OF STORMS FOR THE MTNS AND
DESERTS UNTIL WE ACTUALLY SEE A MAJOR SHIFT IN THE UPPER LEVEL
REGIME...ESPECIALLY SINCE STORMS ARE CLIMATOLOGICALLY FAVORED THIS
TIME OF YEAR.

LOOKING AHEAD...THE LONGER RANGE GFS MODEL BUILDS THE UPPER HIGH
BACK NEAR THE FOUR CORNERS AREA AND TRIES TO BRING THE REMNANTS OF
IGNACIO NORTH EARLY NEXT WEEK. BASED ON THIS SOLUTION...THE THREAT
FOR MTN THUNDERSTORMS WILL CONTINUE FOR THE FORESEEABLE FUTURE.

SAN...FLOOD WATCH...SEE LAXFLSSGX.
   ...SEVERE THUNDERSTORM WATCH...LAXSEL6

Hazardous weather outlook, Aug 26, 1:05 PM PST, 26 minutes before

CAZ042-043-048-050-055>058-060>062-271300-

HAZARDOUS WEATHER OUTLOOK...UPDATE
NATIONAL WEATHER SERVICE SAN DIEGO CA
205 PM PDT TUE AUG 26 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR
EXTREME SOUTHWESTERN CALIFORNIA.

.DAY ONE... TODAY THROUGH TONIGHT

SEVERE THUNDERSTORM WATCH NUMBER 896 UNTIL 700 PM PDT THIS EVENING
FOR THE MOUNTAINS AND DESERTS OF EXTREME SOUTHWEST CALIFORNIA. REFER
TO LAXSLSCA WWUS66 KLOX OR SEL6 WWWUS20 KWNS FOR DETAILS.

FLASH FLOOD WATCH FOR THE MOUNTAINS AND DESERTS OF EXTREME SOUTHWEST
CALIFORNIA FROM NOON THROUGH 800 PM TONIGHT. REFER TO LAXFLSSGX
WGUS86 KSGX FOR DETAILS.

.DAYS TWO THROUGH SEVEN... WEDNESDAY THROUGH MONDAY

POSSIBLE THUNDERSTORMS WITH LOCAL HEAVY RAIN FOR...
SAN BERNARDINO COUNTY MOUNTAINS...
RIVERSIDE COUNTY MOUNTAINS...
SAN DIEGO COUNTY MOUNTAINS...
APPLE AND YUCCA VALLEYS...
COACHELLA VALLEY...
SAN DIEGO COUNTY DESERTS...
TUESDAY THROUGH WEDNESDAY.

.SPOTTER INFORMATION STATEMENT...

SKYWARN ACTIVATION MAY BE REQUIRED TODAY.

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

1 flash flood. Local standard time, as filed.

Flash Flood, San Diego

When: August 26, 1:31 PM PST to 2:00 PM PST
Where: San Diego County, 8 mi E of Santa Ysabel
Property damage: $50,000
Reported by: LAW ENFORCEMENT
Coordinates: 33.028, -116.770 (the zone’s center; the record gives no point)

What these are

Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in California in 2003 Every state in 2003 This day in weather history Warnings in California, August 2003

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5369440.