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FGUS76 KSGX 170947
ESFSGX

Hydrologic Forecast for Extreme Southwestern California
National Weather Service San Diego CA
247 AM PDT Thu Jul 17 2025

...Flash Flood Potential Index for Extreme Southwestern California...

.SYNOPSIS...
Monsoonal moisture will increase today, decrease slightly on
Friday, with a greater decrease over the weekend. This will bring
a chance of showers and thunderstorms through Friday, most
likely over the mountains and during the afternoons.

Chances for measurable rainfall have increased to 25 to 45
percent for the mountains today and remaining in that range for
the San Bernardino Mountains and Riverside County mountains for
Friday. Chances for one-quarter inch or more of rainfall has
increased to 10 to 20 percent with chances for one-half inch or
more of 5 to 10 percent.

For today, increasing mid and high cloud cover may limit daytime
heating with afternoon convection more elevated and less tied to
terrain with lesser chances for thunderstorms and isolated heavier
rainfall.

For Friday, there may be greater clearing of the mid and high
clouds, but with sufficient remaining moisture for thunderstorm
development over the San Bernardino Mountains and Riverside County
mountains during the afternoon with isolated brief heavier
rainfall.

$$

CAZ055-056-058-180230-
San Bernardino County Mountains-Riverside County Mountains-
San Diego County Mountains-
Including the cities of Crestline, Lake Arrowhead, Big Bear City,
Big Bear Lake, Running Springs, Wrightwood, Idyllwild-Pine Cove,
Julian, and Pine Valley
247 AM PDT Thu Jul 17 2025

.TODAY...Low...the risk of flash flooding is minimal.
.FRIDAY...Low...the risk of flash flooding is minimal.

$$

CAZ060>062-065-180230-
Apple and Lucerne Valleys-Coachella Valley-
San Diego County Deserts-San Gorgonio Pass near Banning-
Including the cities of Victorville, Hesperia, Apple Valley,
Lucerne Valley, Indio, Palm Springs, Cathedral City, Palm Desert,
Palm Desert Country, La Quinta, Coachella, and Borrego Springs
247 AM PDT Thu Jul 17 2025

.TODAY...None...no flash flooding is expected.
.FRIDAY...None...no flash flooding is expected.

$$

CAZ048-050-180230-
San Bernardino and Riverside County Valleys-The Inland Empire-
San Diego County Valleys-
Including the cities of Riverside, San Bernardino, Ontario,
Moreno Valley, Fontana, Rancho Cucamonga, Corona, Escondido,
El Cajon, San Marcos, La Mesa, Santee, and Poway
247 AM PDT Thu Jul 17 2025

.TODAY...None...no flash flooding is expected.
.FRIDAY...None...no flash flooding is expected.

$$

CAZ043-057-552-554-180230-
San Diego County Coastal Areas-Santa Ana Mountains and Foothills-
Orange County Coastal Areas-Orange County Inland Areas-
Including the cities of Oceanside, Vista, Carlsbad, Encinitas,
Chula Vista, National City, San Diego, Huntington Beach,
Costa Mesa, Newport Beach, Laguna Beach, San Clemente, Santa Ana,
Anaheim, Garden Grove, Irvine, Orange, Fullerton,
and Mission Viejo
247 AM PDT Thu Jul 17 2025

.TODAY...None...no flash flooding is expected.
.FRIDAY...None...no flash flooding is expected.

$$

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