251
FXUS66 KSGX 102029
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
129 PM PDT WED SEP 10 2025
SYNOPSIS
A LOW MOVING INTO CALIFORNIA IS USHERING IN COOLER TEMPERATURES
WITH HIGHS FOR INLAND AREAS 10 TO 15 DEGREES BELOW AVERAGE TODAY
AND THURSDAY. THERE WILL BE INLAND WARMING OF AROUND 5 DEGREES FOR
FRIDAY AND SATURDAY WITH NOT MUCH CHANGE FOR SUNDAY, BEFORE
BETTER WARMING INTO WEDNESDAY. MONSOONAL MOISTURE MAY MAKE A
RETURN DURING THE MIDDLE AND LATTER PART OF NEXT WEEK.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
SKIES CLEARED QUICKLY TODAY DESPITE A DEEPER MARINE LAYER THAT
RESULTED IN SOME PATCHY DRIZZLE THIS MORNING. COOLER WEATHER AND A
DEEP MARINE LAYER WILL PREVAIL THE NEXT TWO DAYS AS AN UPPER LEVEL
LOW MOVES DOWN INTO CENTRAL CALIFORNIA. 850MB TEMPS WILL RANGE FROM
12-14C THROUGH THE END OF THE WEEK, INDICATING HIGHS IN THE 60S AND
70S FOR THE COAST, VALLEYS, AND INLAND AREAS, 60S FOR THE MOUNTAINS,
AND LOW 90S FOR THE DESERTS. WHILE NOT AS PREVALENT AS THE PREVIOUS
DAYS, A TIGHTER GRADIENT WILL USHER IN SOME GUSTIER WINDS FOR THE
DESERT SLOPES OF THE MOUNTAINS AND MOUNTAIN PASSES INTO THURSDAY
MORNING, GUSTING NEAR 50 MPH AT TIMES. DESPITE THE WINDS, THE COOLER
WEATHER IS A WELCOME BREAK AFTER AN ABOVE-NORMAL START TO SEPTEMBER,
WITH TEMPERATURES FOR THE END OF THE WEEK AROUND 7-15 DEGREES BELOW
NORMAL. BY FRIDAY, A WEAK RIDGE IN BETWEEN TWO LOWS WILL INCH
INLAND, PUSHING THE AFOREMENTIONED LOW UP INTO IDAHO/MONTANA. THE
THERMAL RIDGE AXIS WILL BE POSITIONED OVER CALIFORNIA BY SATURDAY,
RETURNING THE REGION TO A WARMING TREND, ALTHOUGH HIGHS MAY STILL BE
SLIGHTLY BELOW NORMAL. BEFORE THE WARMER WEATHER CAN START
CRANKING, A SHORTWAVE TROUGH OFF THE COAST OF LA WILL MOVE
EASTWARD AND INTO CALIFORNIA EARLY SUNDAY, STUNTING THE INFLUENCE
FROM THE WEAK RIDGE. THEREFORE, HIGHS ON SUNDAY LOOK TO REMAIN
STAGNANT FROM SATURDAY, IN THE 70S FOR COASTAL AREAS, LOW TO MID
80S FOR INLAND AREAS, 70S FOR THE MOUNTAINS, AND UPPER 90S FOR
DESERTS. AS THE SHORTWAVE BREAKS DOWN ON MONDAY, TEMPERATURES WILL
BE ABLE TO WARM A BIT OVER SUNDAY.
MODELS BEGIN TO DIFFER HEADING INTO EARLY NEXT WEEK. THERE IS DECENT
CONSENSUS ON A LOW OVER THE PACNW COMING DOWN INTO NEVADA WITH
ADDITIONAL WEAK RIDGING ON THE BACK SIDE OF THIS. SHOULD THIS OCCUR,
A WARMING TREND SHOULD SETTLE ACROSS THE REGION INTO THE MIDDLE
OF THE WEEK WITH HIGHS POTENTIALLY REACHING ABOVE NORMAL BY
WEDNESDAY. OTHER MODELS INDICATE BETTER CHANCES FOR ZONAL FLOW
ALOFT HEADING INTO MID-WEEK, STILL INDICATING A RETURN TO WARMER
WEATHER, WITH LIKELY A SLOWER UPTICK IN TEMPERATURES. MODELS
CONTINUE TO HINT AT THE RETURN OF SOME MONSOONAL MOISTURE AS EARLY
AS MID NEXT WEEK, BUT CONFIDENCE IN THIS REMAINS LOW UNTIL BETTER
ALIGNMENT IS SEEN IN THE MODELS. FOR NOW, DRY CONDITIONS LOOK TO
PREVAIL FOR THE FORECAST PERIOD WITH GENERALLY BELOW AVERAGE
TEMPERATURES.
AVIATION
102000Z...COAST/VALLEYS...LOW CLOUDS WITH VARYING BASES OF 1500 TO
2500 FEET MSL WILL REDEVELOP AND MOVE INLAND AFTER 00Z, EVENTUALLY
TO FILL THE COASTAL BASIN BY 3Z-12Z THURSDAY. PATCHY AND
INTERMITTENT SCATTERING OF SKY CONDITIONS WILL BE POSSIBLE AT TIMES
WITH CLOUDS BEGINNING TO CLEAR OVER INLAND AREAS AROUND 15Z-17Z
THURSDAY, THEN COASTAL AREAS 17-20Z.
MOUNTAINS/DESERTS...VFR CONDITIONS PREVAIL THROUGH LATE THURSDAY
MORNING. STRONG WINDS OF 25-30KT WITH GUSTS UP TO 40KT THROUGH 08Z
THURSDAY IN THE MOUNTAIN PASSES INTO ADJACENT DESERTS, CAUSING LLWS
AND UP/DOWNDRAFTS IN POCKETS IN LEE OF MOUNTAINS.
MARINE
OCCASIONAL NORTHWEST WIND GUSTS EXCEEDING 20 KT IN VICINITY OF SAN
CLEMENTE ISLAND TODAY AND THURSDAY AFTERNOON AND EVENING. OTHERWISE,
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH SUNDAY.
SGX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...NONE.
PUBLIC...ZUBER
AVIATION/MARINE...VILLAFANE
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page