377
FXUS66 KSGX 051153
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
353 AM PST WED NOV 5 2025
SYNOPSIS
THE MARINE LAYER HAS DEEPENED WITH LOW CLOUDS COVERING MUCH OF THE
COAST AND VALLEYS EARLY THIS MORNING. TODAY WILL BE COOLER WITH
GUSTY WINDS FOR THE MOUNTAINS AND DESERTS FOR THIS AFTERNOON AND
EVENING. WINDS WILL WEAKEN AND THE MARINE LAYER WILL BECOME
SHALLOWER FOR THURSDAY THROUGH THE WEEKEND. GREATER WARMING IS
EXPECTED ON FRIDAY WITH LESSER WARMING CONTINUING THROUGH THE
WEEKEND. A LOW PRESSURE SYSTEM WELL TO THE WEST OF CALIFORNIA WILL
MOVE SLOWLY TOWARD THE COAST NEXT WEEK. THIS WILL BRING A COOLING
TREND WITH INCREASING CHANCES FOR PRECIPITATION FOR THE MIDDLE
AND LATTER PART OF NEXT WEEK.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
SHORT TERM (TODAY THROUGH FRIDAY)
A LOW PRESSURE SYSTEM CENTERED OVER THE GULF OF ALASKA HAS
STRENGTHENED THE ONSHORE FLOW ACROSS SOUTHERN CALIFORNIA. THE
MARINE LAYER HAS DEEPENED TO 2500 TO 3000 FEET DEEP WITH LOW
CLOUDS OVER THE COAST WATERS EXTENDING INLAND ACROSS COASTAL AREAS
AND MOST OF THE VALLEYS. CLOUD BASES NEAR THE COAST ARE 2000 TO
2500 FEET WITH THE SATURATED CLOUD LAYER AROUND 1000 FEET DEEP.
THERE HAS BEEN LITTLE OR NO PRECIPITATION SO FAR OVER THE SOUTHERN
CALIFORNIA COASTAL WATERS OVERNIGHT WITH LITTLE OR NO
PRECIPITATION EXPECTED INTO THIS MORNING. DRIER WEATHER WILL THEN
FOLLOW INTO EARLY NEXT WEEK.
FOR THE MOUNTAINS AND DESERTS, THERE WILL BE STRONGER SOUTHWEST
WINDS FOR THE MOUNTAINS AND DESERTS FOR THIS AFTERNOON AND EVENING
WITH THE STRONGER GUSTS TO 25 TO 35 MPH ALONG AND BELOW THE
COASTAL SLOPES OF THE MOUNTAINS WITH GUSTS TO AROUND 45 MPH FOR
THE NORTHERN COACHELLA VALLEY BELOW THE SAN GORGONIO PASS.
HIGH TEMPERATURES TODAY WILL BE COOLER FOR MOST AREAS, AS MUCH AS
4 TO 8 DEGREES COOLER THAN TUESDAY FOR THE VALLEYS. HIGH
TEMPERATURES FOR TODAY WILL RANGE FROM THE MID TO UPPER 60S NEAR
THE COAST TO THE LOWER TO MID 70S FOR THE VALLEYS WITH THE UPPER
80S FOR THE LOWER DESERTS. NOT MUCH CHANGE IS EXPECTED FOR
THURSDAY WITH WARMING ON FRIDAY OF AS MUCH AS 5 TO 10 DEGREES FOR
THE VALLEYS. HIGH TEMPERATURES ON FRIDAY WILL RANGE FROM AROUND 70
NEAR THE COAST TO THE LOWER TO MID 80S FOR THE INLAND EMPIRE WITH
THE UPPER 80S TO AROUND 90S FOR THE LOWER DESERTS.
THE MARINE LAYER WILL BECOME SHALLOWER FOR THURSDAY AND FRIDAY
WITH NIGHT AND MORNING COASTAL LOW CLOUDS NOT AS EXTENSIVE AND NOT
SPREADING AS FAR INTO THE VALLEYS.
LONG TERM (SATURDAY THROUGH TUESDAY)
HIGH PRESSURE ALOFT TO THE SOUTHWEST OF THE AREA WILL STRENGTHEN
ACROSS CALIFORNIA FOR THE WEEKEND. HIGH TEMPERATURES WILL WARM
ANOTHER DEGREE OR TWO ON SATURDAY AND ANOTHER FEW DEGREES ON
SUNDAY FOR THE COAST AND VALLEYS. WITH THE WARMING, HIGH
TEMPERATURES ON SUNDAY WITH BE AS MUCH AS 8 TO 12 DEGREES ABOVE
AVERAGE FOR THE INLAND VALLEYS, RANGING FROM THE LOWER TO MID 70S
NEAR THE COAST TO THE 80S FOR THE VALLEYS WITH THE LOWER DESERTS
AROUND 90. THE MARINE LAYER WILL BE SHALLOWER WITH NIGHT AND
MORNING LOW CLOUDS NOT EXTENDING INLAND MUCH PAST THE COASTAL
AREAS.
FOR MONDAY AND TUESDAY, A LOW PRESSURE SYSTEM WELL OFF THE
CALIFORNIA COAST WILL MOVE SLOWLY TOWARD THE COAST. THIS WILL
BRING A COOLING TREND AND DEEPENING OF THE MARINE LAYER WITH
INCREASING CHANCES OF PRECIPITATION BY THURSDAY.
AS FAR AS PRECIPITATION FOR NEXT WEEK, CLUSTER ANALYSIS SHOWS A
SCENARIO THAT IS A LITTLE FASTER IN MOVING THE LOW PRESSURE
SYSTEM EASTWARD AND INLAND AROUND WEDNESDAY WITH PRECIPITATION
AMOUNTS A LITTLE LESS. ANOTHER SCENARIO HAS A SLOWER AND STRONGER
SYSTEM ARRIVING LATER IN THE WEEK AROUND THURSDAY AND FRIDAY WITH
GREATER POTENTIAL FOR GREATER PRECIPITATION AMOUNTS. CALIBRATED
NBM DAILY CHANCES FOR MEASURABLE RAINFALL ARE LESS THAN 10 PERCENT
ON TUESDAY, INCREASE TO AROUND 20 PERCENT FOR WEDNESDAY, AND 40
PERCENT FOR THURSDAY AND FOR FRIDAY WITH THE CHANCE FOR ONE INCH
OR MORE OF RAINFALL AT BIG BEAR FOR THURSDAY THROUGH FRIDAY AROUND
20 PERCENT. UNCALIBRATED ECMWF ENSEMBLE OUTPUT HAS HIGHEST
PROBABILITIES FOR ONE INCH OR MORE OF RAINFALL FOR THE MOUNTAINS
IN SAN BERNARDINO COUNTY OF 50 TO 60 PERCENT FROM MIDDAY THURSDAY
TO MIDDAY FRIDAY.
AVIATION
051030Z...COASTS/VALLEYS...LOW CLOUDS BASED 1500-2500 FEET MSL, TOPS
AROUND 3000 FEET, ALONG WITH VIS 0-5SM INLAND VALLEYS AND FOOTHILLS
WILL RISE A LITTLE THROUGH THE MORNING. SCATTER OUT 17-19Z, BUT MAY
BE INTERMITTENT. LOW CLOUD CIGS TO DEVELOP, MORE LIKELY INLAND
BETWEEN 01-05Z, INCREASING IN COVERAGE IN THE ENTIRE COASTAL BASIN
OVERNIGHT, BUT PROBABLY NOT ACHIEVING FULL UNIFORM COVERAGE THURSDAY
MORNING. BASES 2500-3500 FEET MSL WITH TOPS AROUND 4500 FEET.
MOUNTAINS/DESERTS...SOME HIGH CLOUDS TODAY AND TONIGHT. SOUTHWEST TO
WEST WINDS GUSTING 35 TO 40 KNOTS AFTER 20-06Z MOUNTAIN RIDGES INTO
DESERTS, PRODUCING AREAS OF STRONG UP/DOWNDRAFTS.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH SUNDAY.
BEACHES
SURF WILL INCREASE THURSDAY, PEAK THURSDAY NIGHT, AND GRADUALLY
DIMINISH FRIDAY. SURF OF 3-6 FEET IS EXPECTED, LOCALLY HIGHER ON
WEST-FACING BEACHES, PRODUCING A HIGH RIP CURRENT RISK. IN ADDITION,
VERY HIGH TIDES WILL COMBINE WITH THE ELEVATED SURF TO INCREASE THE
RISK OF MINOR TIDAL OVERFLOW LATE THURSDAY AND FRIDAY.
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/BEACHES...MM
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