333
FXUS66 KSGX 051702
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
902 AM PST WED NOV 5 2025
SYNOPSIS
COOLER CONDITIONS EXPECTED TODAY WITH PERIODS OF GUSTY WINDS OVER
THE MOUNTAINS AND INTO THE DESERTS THIS AFTERNOON AND EVENING.
CONDITIONS WILL WARM INTO THE WEEKEND, WITH TEMPERATURES PEAKING ON
SUNDAY. A PATTERN CHANGE IS EXPECTED SOMETIME MID TO LATE NEXT WEEK.
WHILE THERE REMAINS UNCERTAINTY IN THE DETAILS COOLER, BREEZIER, AND
WETTER CONDITIONS ARE POSSIBLE.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
A PASSING WEAK SHORTWAVE HAS INCREASED ONSHORE FLOW THIS MORNING.
THIS HAS HELPED DEEPEN THE MARINE LAYER WITH PATCHY LOW CLOUD
COVERAGE FROM THE COAST TO THE COASTAL MOUNTAIN SLOPES OVERNIGHT AND
THIS MORNING. ANY LINGERING LOW CLOUDS SHOULD CLEAR QUICKLY THIS
MORNING, LEAVING MOSTLY CLEAR SKIES ACROSS THE AREA. THE INCREASED
PRESSURE GRADIENT WILL ALSO RESULT IN AN INCREASE IN SOUTHWEST WINDS
FOR THE MOUNTAINS AND DESERTS THIS AFTERNOON AND EVENING. WIND GUSTS
OF 25 TO 45 MPH ARE EXPECTED. STRONGEST WINDS ARE EXPECTED ON THE
DESERT SLOPES OF THE SAN BERNARDINO MOUNTAINS INTO THE HIGH DESERT
AND THROUGH THE SAN GORGONIO PASS.
HIGH TEMPERATURES TODAY WILL BE A FEW DEGREES COOLER THAN YESTERDAY,
MOST NOTABLY IN THE INLAND VALLEYS. HIGHS ON THURSDAY WILL BE A FEW
DEGREES WARMER WEST OF THE MOUNTAINS, WITH SIMILAR TEMPERATURES TO A
FEW DEGREES OF COOLING IN THE DESERTS. AN AREA OF HIGH PRESSURE
ALOFT WILL STRENGTHEN OVER THE WEEKEND, BRINGING A PERIOD OF
WARMING. ON FRIDAY, HIGHS WEST OF THE MOUNTAINS WILL BE 5 TO 10
DEGREES WARMER THAN THURSDAY. THE WARMING WILL CONTINUE INTO SUNDAY,
WHICH IS WHEN THE HEAT IS EXPECTED TO PEAK AT 8 TO 12 DEGREES ABOVE
AVERAGE FOR THE INLAND VALLEYS. A FEW DEGREES OF COOLING IS EXPECTED
MONDAY, WITH CONTINUED COOLING INTO THE MIDDLE OF THE WEEK.
ADDITIONALLY, THE MARINE LAYER IS EXPECTED TO BE SHALLOWER FOR
THURSDAY THROUGH THE WEEKEND. PATCHY LOW CLOUDS MAY MAKE INTO
PORTIONS OF THE VALLEYS THROUGH FRIDAY, WITH LOW CLOUDS STAYING
MOSTLY CONFINED TO COASTAL AREAS OVER THE WEEKEND.
AN AREA OF LOW PRESSURE WILL DEVELOP OFF THE US WEST COAST EARLY
NEXT WEEK AND SLOWLY MOVE EAST. FASTER SOLUTIONS IN THE ENSEMBLE
CLUSTER ANALYSIS INDICATE THAT PRECIPITATION COULD OCCUR AS EARLY AS
WEDNESDAY NEXT WEEK, WITH SLOWER SOLUTIONS PUSHING ANY PRECIPITATION
TO THURSDAY OR FRIDAY. IT'S ALSO WORTH NOTING THAT THE SLOWER
SOLUTIONS ARE ALSO INDICATING HIGHER AMOUNTS OF RAINFALL ARE
POSSIBLE. 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 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. WHILE OUR CONFIDENCE IN PRECIPITATION
OCCURRING IS INCREASING FOR THE MIDDLE TO END OF NEXT WEEK, THERE IS
STILL A CONSIDERABLE AMOUNT OF UNCERTAINTY IN THE TIMING AND AMOUNT
EXPECTED. THE STRENGTH AND DEPTH OF THE INCOMING TROUGH WILL ALSO
HAVE AN IMPACT IN OUR TEMPERATURE AND WIND FORECAST, WITH A STRONGER
AND DEEPER TROUGH BRINGING COOLER AND WINDIER CONDITIONS.
AVIATION
051630Z...COASTS/VALLEYS...LOW CLOUDS BASED AROUND 1,500-3,000 FEET
MSL WITH TOPS AROUND 3500 FEET WILL CONTINUE TO RISE A LITTLE
THROUGH THE MORNING, ALONG WITH VIS 0-5SM AT INLAND VALLEYS AND
FOOTHILLS . LOW CLOUDS WILL SCATTER OUT BY 17-19Z, BUT MAY BE
INTERMITTENT. LOW CLOUD CIGS WILL REDEVELOP, MORE LIKELY INLAND
BETWEEN 01-05Z THURSDAY, AND INCREASE IN COVERAGE IN THE COASTAL
BASIN OVERNIGHT. LOW CLOUD BASES ARE ANTICIPATED TO BE AROUND 2,500-
3,500 FEET MSL, WITH TOPS AROUND 4,500 FEET MSL, AND WILL LIKELY BE
PATCHY IN NATURE. LOW CIGS WILL BEGIN TO CLEAR THURSDAY STARTING IN
COASTAL/INLAND SAN DIEGO COUNTY AFTER 09Z, THEN BEGIN TO CLEAR AFTER
17Z FOR THE INLAND EMPIRE AND ORANGE COUNTY.
MOUNTAINS/DESERTS...HIGH CLOUDS OVER THE MOUNTAINS AND DESERTS TODAY
AND TONIGHT, CLEARING FOR THURSDAY AFTERNOON. AFTER 20-06Z,
SOUTHWEST TO WEST WINDS WITH GUSTS 35 TO 40 KNOTS ARE EXPECTED IN
THE MOUNTAIN RIDGES AND 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...CO
AVIATION/MARINE/BEACHES...VILLAFANE
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