475
FXUS66 KSGX 231132
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
432 AM PDT WED SEP 23 2026
SYNOPSIS
IT WILL BE WARMER THROUGH SATURDAY WITH MODERATE HEATRISK ON
FRIDAY AND SATURDAY FOR SOME COASTAL AND WESTERN VALLEY AREAS.
THERE IS ALSO A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE
MOUNTAINS ON THURSDAY AFTERNOON. A LOW PRESSURE SYSTEM MOVING
INLAND ALONG THE WEST COAST AND MID AND HIGH CLOUDS FROM TROPICAL
MOISTURE TO THE SOUTH WILL BRING COOLING FOR SUNDAY AND MONDAY.
THEN WARMER UNDER HIGH PRESSURE FOR NEXT TUESDAY.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
..UPDATED AVIATION DISCUSSION
SHORT TERM (TODAY THROUGH FRIDAY)
A WEAK UPPER LEVEL LOW PRESSURE SYSTEM OFF THE COAST OF NORTHERN
BAJA WILL BRING WEAK EASTERLY WINDS TO THE MOUNTAINS FOR THIS
MORNING AND AGAIN THURSDAY MORNING WITH GUSTS LESS THAN 25 MPH.
THIS WILL ALSO BRING SOME MID-LEVEL MONSOONAL MOISTURE NORTHWARD
INTO THE AREA FOR THIS AFTERNOON AND THURSDAY AFTERNOON WITH THE
PRECIPITABLE WATER VALUES HIGHER ON THURSDAY. THIS WILL BRING SOME
CLOUDS TO THE MOUNTAINS FOR THIS AFTERNOON AND A LESS THAN 20
PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE MOUNTAINS FOR
THURSDAY AFTERNOON. THE HRRR ALSO SHOWS SOME CONVECTIVE
DEVELOPMENT ALONG THE ELSINORE CONVERGENCE ZONE IN THE INLAND
EMPIRE ON THURSDAY AFTERNOON. THIS WILL BE FOLLOWED BY SOME DRYING
ON FRIDAY.
HIGH TEMPERATURES TODAY WILL WARM AS MUCH AS 5 TO 10 DEGREES FOR
THE INLAND VALLEYS WITH HIGH TEMPERATURES AS MUCH AS 4 TO 8
DEGREES ABOVE AVERAGE FOR THE VALLEYS AND INLAND ORANGE COUNTY
WITH HIGH TEMPERATURES WITHIN A FEW DEGREES OF AVERAGE ELSEWHERE.
HIGH TEMPERATURES FOR TODAY WILL RANGE FROM THE MID 70S TO LOWER
80S NEAR THE COAST TO THE 90S FOR THE INLAND EMPIRE WITH 100 TO
104 FOR THE LOWER DESERTS. NOT MUCH CHANGE IS EXPECTED ON
THURSDAY.
ON FRIDAY, BOTH HIGH AND LOW TEMPERATURES WILL WARM SLIGHTLY WITH
MODERATE HEATRISK FOR THE COASTAL AREAS AND PORTIONS OF THE
WESTERN VALLEYS IN SAN DIEGO COUNTY AND IN PORTIONS OF INLAND
ORANGE COUNTY.
THE MARINE LAYER HAS DECREASED IN DEPTH TO AROUND 2500 FEET. IT
WILL CONTINUE TO SLOWLY DECREASE IN DEPTH INTO FRIDAY WITH NIGHT
AND MORNING COASTAL LOW CLOUDS NOT SPREADING INLAND PAST THE
WESTERN VALLEYS.
LONG TERM (SATURDAY THROUGH TUESDAY)
FRIDAY NIGHT WILL BE SLIGHTLY WARMER WITH NOT MUCH CHANGE IN HIGH
TEMPERATURES ON SATURDAY. MODERATE HEATRISK WILL CONTINUE ON
SATURDAY FOR THE SAME AREAS AS ON FRIDAY, COASTAL AREAS AND
PORTIONS OF THE WESTERN VALLEYS IN SAN DIEGO COUNTY AND IN
PORTIONS OF INLAND ORANGE COUNTY.
MID AND HIGH CLOUDS FROM TROPICAL MOISTURE AND A LOW PRESSURE
SYSTEM MOVING INLAND ALONG THE WEST COAST WILL SPREAD COOLING
INLAND ON SUNDAY AND MONDAY. HIGH TEMPERATURES ON SUNDAY WILL COOL
A FEW DEGREES NEAR THE COAST TO AS MUCH AS 4 TO 8 DEGREES FOR THE
INLAND VALLEYS WITH HIGH TEMPERATURES COOLING A FEW MORE DEGREES
ON MONDAY. WITH THE COOLING, HIGH TEMPERATURES ON MONDAY WILL BE
AS MUCH AS 5 DEGREES BELOW AVERAGE FOR THE MOUNTAINS, INLAND
VALLEYS, AND HIGH DESERT. HIGH TEMPERATURES ON MONDAY WILL RANGE
FROM THE 70S NEAR THE COAST TO THE 80S FOR THE INLAND EMPIRE WITH
THE LOWER DESERTS IN THE MID 90S. ON TUESDAY, HIGH PRESSURE OVER
SOUTHERN CALIFORNIA WILL BRING WARMING WITH DECREASING MID AND
HIGH CLOUDS.
ANY SURF IMPACTS TO THE COAST OF ORANGE AND SAN DIEGO COUNTIES
FROM HURRICANE POLO WOULD MOST LIKELY BE AFTER THE WEEKEND. THE
CURRENT TRACK FORECAST THROUGH THE WEEKEND WOULD MOST BE OUTSIDE
OF THE THE SWELL WINDOW THE COAST OF ORANGE AND SAN DIEGO
COUNTIES. THERE IS GREATER SPREAD IN THE TRACK FORECAST BEYOND THE
WEEKEND AND ANY RESULTING POTENTIAL SWELL AND SURF IMPACTS ALONG
THE COAST FOR EARLY NEXT WEEK.
AVIATION
231130Z...COAST/VALLEYS...AREAS OF LOW CLOUDS BASED AROUND 1500
FEET MSL THIS MORNING MAINLY IN SAN DIEGO COUNTY. ANY CIGS TO
SCATTER OUT 16- 17Z. LOW CLOUDS BASED AROUND 1500 FEET MSL TO
GRADUALLY INCREASE AFTER 02Z THIS EVE, BECOMING RATHER UNIFORM
AFTER 10Z.
OTHERWISE...MOSTLY CLEAR SKIES WITH UNRESTRICTED VIS TODAY AND
TONIGHT.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH SUNDAY.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...NONE.
PUBLIC...17
AVIATION/MARINE...MM
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