935
FGUS76 KSGX 170959
ESFSGX
HYDROLOGIC FORECAST FOR EXTREME SOUTHWESTERN CALIFORNIA
NATIONAL WEATHER SERVICE SAN DIEGO CA
259 AM PDT WED SEP 17 2025
..FLASH FLOOD POTENTIAL INDEX FOR EXTREME SOUTHWESTERN CALIFORNIA
SYNOPSIS
MOISTURE FROM THE REMNANTS OF TROPICAL STORM MARIO WILL INCREASE
INTO THURSDAY WITH CHANCES SHOWERS AND THUNDERSTORMS GREATEST ON
THURSDAY, ESPECIALLY FOR THE MOUNTAINS AND DESERTS. THE GREATEST
POTENTIAL FOR HEAVIER RAINFALL ON THURSDAY IS MAINLY FOR THE
MOUNTAINS AND HIGH DESERT, POSSIBLY EXTENDING INTO THE INLAND
EMPIRE AND INTO THE LOWER DESERTS. BANDS OF THUNDERSTORMS
TRACKING ACROSS THE SAME AREA WOULD BE THE MOST LIKELY SCENARIO
FOR PRODUCING HEAVIER RAINFALL TOTALS. THERE COULD BE ISOLATED
HOURLY RAINFALL ON THURSDAY OF 0.75 TO 1 INCH.
CAZ056-058-180245-
RIVERSIDE COUNTY MOUNTAINS-SAN DIEGO COUNTY MOUNTAINS-
INCLUDING THE CITIES OF IDYLLWILD-PINE COVE, JULIAN,
AND PINE VALLEY
259 AM PDT WED SEP 17 2025
TODAY...MODERATE
THUNDERSTORMS ARE EXPECTED TO DEVELOP AND
ISOLATED FLASH FLOODING IS POSSIBLE.
THURSDAY...MODERATE
THUNDERSTORMS ARE EXPECTED TO DEVELOP AND
ISOLATED FLASH FLOODING IS POSSIBLE.
CAZ055-060>062-065-180245-
SAN BERNARDINO COUNTY MOUNTAINS-APPLE AND LUCERNE VALLEYS-
COACHELLA VALLEY-SAN DIEGO COUNTY DESERTS-
SAN GORGONIO PASS NEAR BANNING-
INCLUDING THE CITIES OF CRESTLINE, LAKE ARROWHEAD, BIG BEAR CITY,
BIG BEAR LAKE, RUNNING SPRINGS, WRIGHTWOOD, VICTORVILLE,
HESPERIA, APPLE VALLEY, LUCERNE VALLEY, INDIO, PALM SPRINGS,
CATHEDRAL CITY, PALM DESERT, PALM DESERT COUNTRY, LA QUINTA,
COACHELLA, AND BORREGO SPRINGS
259 AM PDT WED SEP 17 2025
TODAY...LOW
THE RISK OF FLASH FLOODING IS MINIMAL.
THURSDAY...MODERATE
THUNDERSTORMS ARE EXPECTED TO DEVELOP AND
ISOLATED FLASH FLOODING IS POSSIBLE.
CAZ048-180245-
SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-
INCLUDING THE CITIES OF RIVERSIDE, SAN BERNARDINO, ONTARIO,
MORENO VALLEY, FONTANA, RANCHO CUCAMONGA, AND CORONA
259 AM PDT WED SEP 17 2025
TODAY...LOW
THE RISK OF FLASH FLOODING IS MINIMAL.
THURSDAY...MODERATE
THUNDERSTORMS ARE EXPECTED TO DEVELOP AND
ISOLATED FLASH FLOODING IS POSSIBLE.
CAZ050-180245-
SAN DIEGO COUNTY VALLEYS-
INCLUDING THE CITIES OF ESCONDIDO, EL CAJON, SAN MARCOS, LA MESA,
SANTEE, AND POWAY
259 AM PDT WED SEP 17 2025
TODAY...LOW
THE RISK OF FLASH FLOODING IS MINIMAL.
THURSDAY...MODERATE
THUNDERSTORMS ARE EXPECTED TO DEVELOP AND
ISOLATED FLASH FLOODING IS POSSIBLE.
CAZ043-057-552-554-180245-
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
259 AM PDT WED SEP 17 2025
TODAY...LOW
THE RISK OF FLASH FLOODING IS MINIMAL.
THURSDAY...LOW
THE RISK OF FLASH FLOODING IS MINIMAL.
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