915  
FXUS66 KSGX 241127  
AFDSGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN DIEGO CA  
327 AM PST WED DEC 24 2025  
   
SYNOPSIS  
 
HEAVY RAIN WILL MOVE SOUTHWARD ACROSS THE AREA TODAY ALONG WITH A  
SLIGHT CHANCE OF THUNDERSTORMS. THE HEAVY RAIN WILL DECREASE FROM  
THE NORTHWEST THIS EVENING WITH SCATTERED SHOWERS CONTINUING  
THROUGH CHRISTMAS DAY. ANOTHER ROUND OF MORE WIDESPREAD SHOWERS IS  
EXPECTED FOR THURSDAY NIGHT AND FRIDAY. GUSTY SOUTH WINDS WILL  
CONTINUE THROUGH THIS EVENING WITH GUSTS TO 40 MPH NEAR THE COAST  
AND TO 55 TO 75 MPH ALONG THE DESERT SLOPES OF THE SAN BERNARDINO  
COUNTY MOUNTAINS. SNOW LEVELS ABOVE 9000 FEET THIS MORNING WILL  
FALL TO AROUND 6500 TO 7500 FEET ON THURSDAY AND THURSDAY NIGHT,  
THEN FALL TO AROUND 5500 FEET FOR THE WEEKEND. CHANCES FOR SHOWERS  
WILL DECREASE FOR THE WEEKEND, THEN MAY INCREASE AGAIN AROUND  
WEDNESDAY AND THURSDAY OF NEXT WEEK.  
 
 
   
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE  
 
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO  
COUNTIES...  
 
KEY POINTS:  
 
* WIDESPREAD MODERATE TO HEAVY RAINFALL TODAY INTO THIS EVENING  
WITH THE POTENTIAL FOR ROADWAY FLOODING AND LOCALIZED FLASH  
FLOODING FROM THE COAST TO DESERTS. RAPID RISES IN SMALL STREAMS  
AND INCREASED FLOW IN MAIN STEM RIVERS EXPECTED.  
 
* THERE IS A HIGH RISK FOR FLASH FLOODING THROUGH THIS EVENING FOR  
FOR THE SAN BERNARDINO COUNTY MOUNTAINS AND ADJACENT FOOTHILL  
AREAS OF THE INLAND EMPIRE, FLASH FLOODING THAT COULD RESULT IN  
DAMAGING AND POTENTIALLY LIFE-THREATENING FLASH FLOODING, MUD  
SLIDES, AND DEBRIS FLOWS.  
 
* GUSTY SOUTH WINDS WILL STRENGTHEN THIS MORNING AND CONTINUE INTO  
THE EVENING WITH GUSTS TO 45 MPH NEAR THE COAST AND TO 55 TO 75  
MPH ALONG AND BELOW THE DESERT SLOPES OF THE SAN BERNARDINO  
COUNTY MOUNTAINS. MAKE SURE TO SECURE OUTDOOR FURNITURE. TREE  
DAMAGE IS POSSIBLE.  
 
* SCATTERED SHOWERS WILL CONTINUE ON CHRISTMAS DAY WITH ANOTHER  
ROUND OF MORE WIDESPREAD SHOWERS SOME TIME DURING THURSDAY NIGHT  
AND FRIDAY. SNOW LEVELS WILL LOWER TO AROUND 7000 FEET FOR  
THURSDAY INTO THURSDAY EVENING, THEN LOWER TO AROUND 6000-6500  
FEET BY LATE FRIDAY CREATING SLICK CONDITIONS ON MOUNTAIN  
HIGHWAYS.  
 
* THERE IS THE POTENTIAL FOR ANOTHER STORM SYSTEM AROUND NEW  
YEAR'S EVE AND NEW YEAR'S DAY, BUT CONFIDENCE IS EXTREMELY LOW  
WITH REGARDS TO TIMING.  
   
SHORT TERM (TODAY THROUGH FRIDAY)  
 
MOVEMENT OF THE HEAVIER AND WIDESPREAD RAINFALL TOWARD  
SOUTHWESTERN CALIFORNIA HAS SLOWED OVERNIGHT. HOWEVER, THE HEAVIER  
RAINFALL WILL BEGIN TO SPREAD INTO ORANGE AND SOUTHWESTERN SAN  
BERNARDINO COUNTIES AROUND DAWN, THEN MOVE SLOWLY EAST AND SOUTH  
DURING THE DAY, THEN MOVE MORE QUICKLY EASTWARD DURING THE  
EVENING. A FLOOD WATCH CONTINUES FOR ALL OF SOUTHWESTERN  
CALIFORNIA TODAY WITH THE HIGHEST RISK FOR FLASH FLOODING FOR THE  
SAN BERNARDINO COUNTY MOUNTAINS AND ADJACENT FOOTHILL AREAS OF THE  
INLAND EMPIRE.  
 
A HIGH WIND WARNING CONTINUES FOR THE SAN BERNARDINO COUNTY  
MOUNTAINS AND ADJACENT HIGH DESERT INTO THURSDAY AFTERNOON. THE  
STRONGEST WINDS ARE EXPECTED THROUGH THIS AFTERNOON ALONG AND NEAR  
THE DESERT SLOPES OF THE MOUNTAINS. THE STRONGEST GUST OVERNIGHT  
HAS BEEN 91 MPH AT BURNS CANYON ON THE NORTHEAST SLOPES OF THE SAN  
BERNARDINO MOUNTAINS. THAT GUST OCCURRED AROUND 11 PM TUESDAY.  
WINDS WILL STRENGTHEN ALONG THE COAST THIS MORNING WITH GUSTS TO  
AROUND 45 MPH NEAR THE COAST FROM LATE MORNING THROUGH THE  
AFTERNOON.  
 
SCATTERED SHOWERS WILL CONTINUE THROUGH CHRISTMAS DAY WITH  
ADDITIONAL RAINFALL MOSTLY ONE-QUARTER INCH OR LESS, THOUGH  
LOCALLY ONE-HALF TO ONE INCH ON THE COASTAL SLOPES TO THE WEST OF  
THE CAJON PASS.  
 
ANOTHER ROUND OF MORE WIDESPREAD SHOWERS IS EXPECTED TO MOVE  
SOUTHWARD ACROSS THE AREA FOR THURSDAY NIGHT AND FRIDAY, THOUGH  
WITH SOME DIFFERENCES IN TIMING AND AMOUNTS.  
 
 
   
LONG TERM (SATURDAY THROUGH TUESDAY)  
 
CHANCES FOR SHOWERS WILL DECREASE OVER THE WEEKEND AND BE LOWEST  
ON SUNDAY WITH THE CHANCE FOR MEASURABLE PRECIPIATION ON SUNDAY  
AROUND 10 TO 15 PERCENT.  
 
A CUTOFF LOW PRESSURE SYSTEM MAY DEVELOP WELL TO THE SOUTHWEST OF  
THE AREA BY EARLY NEXT WEEK, POSSIBLY MOVING TOWARD THE AREA  
DURING THE MIDDLE AND LATTER PART OF NEXT WEEK. THAT WOULD  
INCREASE CHANCES FOR PRECIPITATION TO SPREAD INTO THE AREA FROM  
THE SOUTH AROUND WEDNESDAY AND THURSDAY OF NEXT WEEK, NEW YEAR'S  
EVE AND NEW YEAR'S DAY.  
 
 
   
AVIATION  
 
231000Z...BKN-OVC REGIONWIDE WITH SEVERAL CLOUD LAYERS BASED 2000-  
5000 FT MSL. SCT -SHRA MOVING NORTHEAST ACROSS THE REGION, BRINGING  
LOCAL BASES 2000-3000 FT MSL AND VIS 3-6 SM. SOUTH TO SOUTHEAST  
WINDS STRENGTHEN THIS MORNING, WITH FREQUENT GUSTS 20-35 KT FOR  
COASTAL/VALLEY SITES AND 40-55 KT OVER THE MTNS INTO PARTS OF THE  
HIGH DESERT THROUGH TODAY. MOD TO STRONG UP/DOWNDRAFTS OVER AND NEAR  
HIGHER TERRAIN.  
 
THE MAIN BAND OF PRECIPITATION MOVES INTO NORTHEAST ORANGE CO/INLAND  
EMPIRE AFTER 17Z OR SO, THEN NORTHEAST SAN DIEGO CO AFTER 20Z. THIS  
WILL BRING MODERATE TO HEAVY PRECIPITATION WITH VIS REDUCTIONS 1-3  
SM AND CIGS LOCALLY AS LOW AS 500-700 FT MSL. EMBEDDED THUNDERSTORMS  
WITH LIGHTNING, HEAVY RAIN, AND ERRATIC WINDS ARE ALSO POSSIBLE  
THROUGH THE REGION TODAY. WIDESPREAD PRECIPITATION WILL GIVE WAY TO  
SCT SHRA AFTER ABOUT 06Z, AND WINDS WILL GRADUALLY DECREASE. CIGS  
WILL CONTINUE TO VARY FREQ THROUGH THE PERIOD WITH A VARIETY OF  
CLOUD LAYERS 1000-5000 FT.  
 
 
   
MARINE  
 
WINDS WILL CONTINUE TO INCREASE THIS MORNING TO GALE FORCE, WITH  
WIND GUSTS UPWARDS OF 35 KTS. THIS WILL BRING STEEP COMBINED SEAS OF  
6-9 FEET. PERIODS OF MODERATE TO HEAVY RAIN TODAY WILL LEAD TO AREAS  
OF POOR VISIBILITY AND THUNDERSTORMS WILL BE POSSIBLE OVER THE OPEN  
WATERS. SOME OF THESE MAY CONTAIN SMALL HAIL, GUSTY WINDS, AND A  
WATERSPOUT OR TWO WILL BE POSSIBLE. WINDS DIMINISH SLIGHTLY LATE  
TODAY, BUT WINDS AND SEAS WILL REMAIN HAZARDOUS TO SMALL CRAFT  
THROUGH EARLY THURSDAY MORNING.  
 
SOUTH TO SOUTHWEST WINDS STRENGTHEN SLIGHTLY AGAIN LATE THURSDAY  
INTO EARLY FRIDAY, WITH GUSTS POSSIBLY EXCEEDING 20 KTS. WINDS THEN  
TURN NORTHWEST AND GRADUALLY DECREASE LATE FRIDAY INTO SATURDAY.  
 
 
   
BEACHES  
 
STRENGTHENING SOUTH WINDS TODAY WILL LEAD TO ELEVATED SURF 5 TO 8  
FEET WITH SETS TO 9 FEET, HIGHEST FOR SOUTH-FACING BEACHES. THIS  
WILL LEAD TO HAZARDOUS SWIMMING CONDITIONS. MINOR TIDAL OVERFLOW FOR  
SOUTH-FACING BEACHES IS ALSO POSSIBLE FROM A COMBINATION OF WINDS  
AND ELEVATED SURF TODAY, ESPECIALLY DURING HIGH TIDE THIS MORNING.  
ADDITIONALLY, THERE IS A SLIGHT CHANCE FOR THUNDERSTORMS, WHICH  
WOULD BRING DANGEROUS LIGHTNING.  
 
WINDS DIMINISH ALONG WITH SURF LATE TODAY, BUT MORE BREEZY WINDS  
ALONG WITH LARGE FRESH SWELL WILL LEAD TO SURF BUILDING AGAIN FRIDAY-  
SATURDAY, ESPECIALLY FOR WEST-FACING BEACHES. A SURF ADVISORY IS IN  
EFFECT FROM TONIGHT TO SATURDAY AFTERNOON.  
 
 
   
HYDROLOGY  
 
A HIGH RISK FOR FLASH FLOODING CONTINUES FOR THE SAN BERNARDINO  
COUNTY MOUNTAINS AND ADJACENT FOOTHILL AREAS OF THE INLAND EMPIRE  
FROM 4 AM TODAY TO 4 AM THURSDAY WITH THE GREATEST RISK THROUGH  
THROUGH EARLY EVENING WITH A GREATER RISK FOR DAMAGING AND  
POTENTIALLY LIFE-THREATENING FLASH FLOODING. A MODERATE RISK FOR  
FLASH FLOODING EXTENDS SOUTHWARD FROM THE HIGH RISK AREA INTO FAR  
NORTHERN SAN DIEGO COUNTY.  
 
MORE WIDESPREAD AND HEAVIER RAINFALL WILL BEGIN TO SPREAD INTO  
ORANGE AND SOUTHWESTERN SAN BERNARDINO COUNTIES AROUND 6 AM, THEN  
MOVE SLOWLY EAST AND SOUTH DURING THE DAY, THEN MOVE MORE QUICKLY  
EASTWARD DURING THE EVENING.  
 
FOR ORANGE AND SOUTHWESTERN SAN BERNARDINO COUNTIES THROUGH  
TONIGHT, RAINFALL WILL RANGE FROM 1.5 TO 2.5 INCHES NEAR THE COAST  
TO 6 TO 8 INCHES IN THE MOUNTAINS WITH LOCAL AMOUNTS EXCEEDING 10  
INCHES IN THE EASTERN SAN GABRIEL MOUNTAINS. AMOUNTS WILL DECREASE  
FROM NORTH TO SOUTH WITH AMOUNTS ACROSS FAR SOUTHERN SAN DIEGO  
COUNTY RANGING FROM AROUND ONE INCH NEAR THE COAST TO 1.5 TO 2  
INCHES IN THE MOUNTAINS. FOR THE HIGH DESERT, 1.5 TO 2.5 INCHES IS  
EXPECTED WITH AS MUCH AS 3 TO 5 INCHES IN THE DESERT FOOTHILL  
AREAS BELOW WRIGHTWOOD. FOR THE LOWER DESERTS, ONE-QUARTER TO ONE-  
HALF INCH IS EXPECTED.  
 
THE HIGHEST RAINFALL RATES TODAY ARE EXPECTED ON THE COASTAL  
SLOPES OF THE SAN BERNARDINO COUNTY MOUNTAINS TODAY. FOR THE  
EASTERN SAN GABRIEL MOUNTAINS, RAINFALL RATES TO ONE-HALF INCH PER  
HOUR ARE EXPECTED TO BEGIN BY DAWN WITH SEVERAL HOURS OF RAINFALL  
RATES AROUND 1 INCH PER HOUR BETWEEN 8 AM AND 4 PM WITH RAINFALL  
RATES TO AROUND ONE-HALF INCH PER HOUR CONTINUING UNTIL EARLY THIS  
EVENING. FOR THE SAN BERNARDINO MOUNTAINS, RAINFALL RATES OF  
AROUND ONE-HALF INCH PER HOUR WILL BEGIN BY LATE MORNING AND  
CONTINUE THROUGH THE AFTERNOON, LOCALLY TO AROUND ONE INCH PER  
HOUR DURING THE AFTERNOON.  
 
SCATTERED SHOWERS WILL CONTINUE THROUGH CHRISTMAS DAY WITH  
ADDITIONAL RAINFALL MOSTLY ONE-QUARTER INCH OR LESS, THOUGH  
LOCALLY ONE-HALF TO ONE INCH ON THE COASTAL SLOPES TO THE WEST OF  
THE CAJON PASS.  
 
ANOTHER ROUND OF MORE WIDESPREAD SHOWERS IS EXPECTED TO MOVE  
SOUTHWARD ACROSS THE AREA FOR THURSDAY NIGHT AND FRIDAY, THOUGH  
WITH SOME DIFFERENCES IN TIMING AND AMOUNTS. FOR ORANGE AND  
SOUTHWESTERN SAN BERNARDINO COUNTIES FOR THURSDAY NIGHT AND FRIDAY,  
RAINFALL COULD RANGE FROM 0.5 TO 1 INCH NEAR THE COAST TO 1.5 TO  
2.5 INCHES IN THE MOUNTAINS WITH LOCALLY GREATER AMOUNTS. AMOUNTS  
WILL DECREASE FROM NORTH TO SOUTH WITH AMOUNTS ACROSS FAR  
SOUTHERN SAN DIEGO COUNTY AROUND ONE-THIRD INCH. FOR THE HIGH  
DESERT, 0.25 TO 0.50 INCH IS EXPECTED WITH ONE-TENTH INCH OR LESS  
FOR THE LOWER DESERTS.  
 
THE SNOW LEVEL WILL RISE ABOVE 9000 FEET EARLY THIS MORNING, FALL  
TO AROUND 6500 TO 7000 FEET FOR LATE TONIGHT THROUGH THURSDAY,  
RISE TO AROUND 7500 FEET FOR LATE THURSDAY NIGHT, THEN FALL TO  
AROUND 5000 FEET FOR THE WEEKEND.  
 
 
   
SKYWARN  
 
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE  
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.  
 
 
   
SGX WATCHES/WARNINGS/ADVISORIES  
 
CA...HIGH SURF ADVISORY UNTIL 11 AM PST SATURDAY FOR ORANGE COUNTY  
COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.  
 
WIND ADVISORY UNTIL 10 PM PST THIS EVENING FOR ORANGE COUNTY  
COASTAL AREAS-ORANGE COUNTY INLAND AREAS-SAN BERNARDINO AND  
RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO COUNTY  
COASTAL AREAS-SAN DIEGO COUNTY VALLEYS-SANTA ANA MOUNTAINS  
AND FOOTHILLS.  
 
FLOOD WATCH THROUGH LATE TONIGHT FOR SAN DIEGO COUNTY COASTAL  
AREAS-SAN DIEGO COUNTY DESERTS-SAN DIEGO COUNTY MOUNTAINS-  
SAN DIEGO COUNTY VALLEYS.  
 
FLOOD WATCH THROUGH THIS EVENING FOR APPLE AND LUCERNE VALLEYS-  
COACHELLA VALLEY-ORANGE COUNTY COASTAL AREAS-ORANGE COUNTY  
INLAND AREAS-RIVERSIDE COUNTY MOUNTAINS-SAN BERNARDINO  
COUNTY MOUNTAINS-SAN BERNARDINO AND RIVERSIDE COUNTY  
VALLEYS-THE INLAND EMPIRE-SAN GORGONIO PASS NEAR BANNING-  
SANTA ANA MOUNTAINS AND FOOTHILLS.  
 
HIGH WIND WARNING UNTIL 3 PM PST THURSDAY FOR APPLE AND LUCERNE  
VALLEYS-SAN BERNARDINO COUNTY MOUNTAINS.  
 
PZ...GALE WARNING UNTIL 4 PM PST THIS AFTERNOON FOR COASTAL WATERS  
FROM SAN MATEO POINT TO THE MEXICAN BORDER AND OUT TO 10 NM-  
WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING  
10 TO 60 NM OUT INCLUDING SAN CLEMENTE ISLAND.  
 
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM PST  
THURSDAY FOR COASTAL WATERS FROM SAN MATEO POINT TO THE  
MEXICAN BORDER AND OUT TO 10 NM-WATERS FROM SAN MATEO POINT  
TO THE MEXICAN BORDER EXTENDING 10 TO 60 NM OUT INCLUDING  
SAN CLEMENTE ISLAND.  
 
 
 
 
 
PUBLIC/HYDROLOGY...17  
AVIATION/MARINE/BEACHES...CSP  
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