156
FGUS76 KSGX 232254
ESFSGX

Hydrologic Forecast for Extreme Southwestern California
National Weather Service San Diego CA
354 PM PDT Sat Aug 23 2025

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

.SYNOPSIS...
Monsoonal moisture will remain in place through Tuesday followed
by gradual drying for Wednesday through Friday.

There will be greater chances for afternoon and early evening
showers and thunderstorms, mostly for the mountains and deserts
each day through Tuesday. Daily chances for one-half inch or more
of rainfall at Big Bear are generally between 15 and 20 percent
each day.

For this afternoon and early evening and again for Sunday
afternoon and early evening, thunderstorms could cause isolated
flash flooding, mainly for the mountains of San Bernardino and
Riverside Counties and for the Lucerne Valley.

$$

CAZ055-056-060-241315-
San Bernardino County Mountains-Riverside County Mountains-
Apple and Lucerne Valleys-
Including the cities of Crestline, Lake Arrowhead, Big Bear City,
Big Bear Lake, Running Springs, Wrightwood, Idyllwild-Pine Cove,
Victorville, Hesperia, Apple Valley, and Lucerne Valley
354 PM PDT Sat Aug 23 2025

.TONIGHT...Moderate...thunderstorms are expected to develop and
isolated flash flooding is possible.
.SUNDAY...Moderate...thunderstorms are expected to develop and
isolated flash flooding is possible.
.MONDAY...Moderate...thunderstorms are expected to develop and
isolated flash flooding is possible.

$$

CAZ058-061-062-065-241315-
San Diego County Mountains-Coachella Valley-
San Diego County Deserts-San Gorgonio Pass near Banning-
Including the cities of Julian, Pine Valley, Indio, Palm Springs,
Cathedral City, Palm Desert, Palm Desert Country, La Quinta,
Coachella, and Borrego Springs
354 PM PDT Sat Aug 23 2025

.TONIGHT...Low...the risk of flash flooding is minimal.
.SUNDAY...Low...the risk of flash flooding is minimal.
.MONDAY...Low...the risk of flash flooding is minimal.

$$

CAZ048-241315-
San Bernardino and Riverside County Valleys-The Inland Empire-
Including the cities of Riverside, San Bernardino, Ontario,
Moreno Valley, Fontana, Rancho Cucamonga, and Corona
354 PM PDT Sat Aug 23 2025

.TONIGHT...Low...the risk of flash flooding is minimal.
.SUNDAY...Low...the risk of flash flooding is minimal.
.MONDAY...Low...the risk of flash flooding is minimal.

$$

CAZ050-241315-
San Diego County Valleys-
Including the cities of Escondido, El Cajon, San Marcos, La Mesa,
Santee, and Poway
354 PM PDT Sat Aug 23 2025

.TONIGHT...Low...the risk of flash flooding is minimal.
.SUNDAY...Low...the risk of flash flooding is minimal.
.MONDAY...Low...the risk of flash flooding is minimal.

$$

CAZ043-057-552-554-241315-
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
354 PM PDT Sat Aug 23 2025

.TONIGHT...None...no flash flooding is expected.
.SUNDAY...None...no flash flooding is expected.
.MONDAY...None...no flash flooding is expected.

$$