491
FXUS66 KSGX 301647
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
847 AM PST SUN NOV 30 2025
SYNOPSIS
DRY AND COOL TODAY. THE MARINE LAYER DEEPENS INTO MONDAY FOR MORE
WIDESPREAD LOW CLOUDS AND FOG EACH NIGHT AND MORNING. WEAK TO
LOCALLY MODERATE SANTA ANA WINDS DEVELOP MONDAY AND WEAKEN TUESDAY
WITH WARMER AND DRIER WEATHER. THERE IS A 15-30% CHANCE OF LIGHT
PRECIPITATION WEDNESDAY AFTERNOON INTO THURSDAY MORNING, FOLLOWED
BY ANOTHER ROUND OF WEAK TO MODERATE SANTA ANA WINDS THURSDAY INTO
FRIDAY. GRADUAL WARMING THURSDAY THROUGH THE WEEKEND WITH HIGHS
NEAR SEASONAL NORMALS.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
MORNING UPDATE...
WHILE A COASTAL EDDY DIDN'T NOT MATERIALIZE THIS MORNING,
INCREASED ONSHORE FLOW FROM A TROUGH DIGGING THROUGH THE GREAT
BASIN HAS ALLOWED THE MARINE LAYER TO DEEPEN AND SPREAD LOW
CLOUDS/FOG INTO THE WESTERN INLAND VALLEYS THIS MORNING. CLOUDS
ARE MORE PATCHY AND STARTING TO MIX OUT IN SOUTHERN SAN DIEGO
COUNTY BUT REMAIN MORE UNIFORM THROUGH ORANGE COUNTY AND THE
NORTHWESTERN INLAND EMPIRE, BUT SHOULD EVENTUALLY CLEAR OUT BY THE
EARLY AFTERNOON. SEE THE PREVIOUS DISCUSSION BELOW FOR MORE
DETAILS ABOUT REMAINDER OF THE FORECAST.
FROM THE PREVIOUS DISCUSSION...
INCREASING ONSHORE FLOW WITH THE TROUGH PASSING BY TO THE NORTH
WILL BRING BREEZY WEST WINDS TO THE MOUNTAINS AND DESERTS,
STRONGEST THROUGH THE PASSES AND ON THE EAST FACING MOUNTAIN
SLOPES WHERE GUSTS 35-45 MPH ARE POSSIBLE THIS AFTERNOON AND
EVENING. THE PASSING TROUGH WILL ALSO RESULT IN COOLER WEATHER
WITH HIGHS NEAR SEASONAL NORMALS.
THE MARINE LAYER CONTINUES TO DEEPEN TONIGHT, POTENTIALLY
SPREADING INTO THE INLAND EMPIRE. SURFACE HIGH PRESSURE BUILDS
OVER THE GREAT BASIN TONIGHT BEHIND THE DEPARTING TROUGH, DRIVING
WEAK TO LOCALLY MODERATE SANTA ANA WINDS BY MONDAY MORNING. WINDS
PEAK DURING THE MORNING AND EARLY AFTERNOON WITH GUSTS 30-45 MPH
BELOW THE PASSES, CANYONS, AND FOOTHILLS. THESE WINDS WILL BRING
MINOR WARMING WEST OF THE MOUNTAINS WHERE HIGHS WILL BE A COUPLE
DEGREES ABOVE NORMAL, WITH COOLING IN THE MOUNTAINS AND DESERTS
DUE TO COLD AIR ADVECTION FROM THE NORTH. SURFACE PRESSURE
GRADIENTS AND WINDS WEAKEN ON TUESDAY, WITH A RETURN OF WEAK
ONSHORE FLOW BY THE AFTERNOON FOR SLIGHT COOLING WEST OF THE
MOUNTAINS AND SLIGHT WARMING IN THE MOUNTAINS AND DESERTS.
FOR THE MIDWEEK SYSTEM, ALL OF THE GLOBAL ENSEMBLES AND
DETERMINISTIC MODELS HAVE TRENDED MORE TOWARDS AN INSIDE TRACK.
BY THURSDAY, ONLY ABOUT 36% PERCENT OF THE MEMBERS MAINTAIN THE
CLOSED LOW OR DEEP TROUGH OVER SO CAL ON THURSDAY COMPARED TO 75%
FROM THE 00Z SATURDAY RUNS. THE TROUGH STILL TRACKS CLOSE ENOUGH
TO MAINTAIN A 15-30% CHANCE OF SHOWERS WEDNESDAY AFTERNOON THROUGH
THURSDAY MORNING, THOUGH WITH THE TREND TOWARDS THE MORE INSIDE
TRACK, PRECIPITATION AMOUNTS HAVE DECREASED. NBM CURRENTLY HAS
AROUND A 25% CHANCE OF 0.10" OR MORE. PRECIPITATION (ASSUMING WE
GET ANY) SHUTS OFF PRETTY QUICKLY ON THURSDAY AS ANOTHER ROUND OF
WEAK TO MODERATE SANTA ANA WINDS DEVELOP BEHIND THE TROUGH. SANTA
ANA WINDS WILL LIKELY CONTINUE INTO FRIDAY. FOR NEXT WEEKEND,
ENSEMBLE SOLUTIONS BEGIN TO DIVERGE SLIGHTLY. AROUND TWO-THRIDS OF
THE MEMBERS MAINTAIN A RIDGE JUST OFF THE WEST COAST AND DRY
NORTHWESTERLY FLOW OVER SO CAL WHICH WOULD RESULT IN WARMER
WEATHER AND PERHAPS ANOTHER ROUND OF OFFSHORE FLOW, WHILE THE
REMAINING MEMBERS BREAK THE RIDGE DOWN AND HAVE MORE ZONAL FLOW
FOR COOLER WEATHER AND MORE PERSISTENT ONSHORE FLOW.
AVIATION
301630Z....COASTS/VALLEYS...LOW CLOUDS BASED 800-1500FT MSL HAVE
CLEARED THE SOUTHERN HALF OF SAN DIEGO COUNTY BUT REMAIN SOCKED IN
ACROSS ORANGE COUNTY. LOW CLOUDS ARE BEGINNING TO FILTER INTO THE
INLAND EMPIRE A BIT BUT ARE UNLIKELY TO BE ABLE TO REACH KONT.
CLOUDS WILL CLEAR BACK TOWARDS THE COAST 18-20Z. PATCHY LOW CLOUDS
WILL REDEVELOP WITH BASES OF 1100-1800FT MSL AND MOVE ASHORE AGAIN
AS EARLY AS 00-01Z MONDAY, BUT WILL STRUGGLE TO MAKE IT VERY FAR
INLAND BEFORE THEY ARE PUSHED BACK TOWARDS THE COAST EARLY MONDAY
MORNING. STILL, SOME LOW CLOUDS WILL LIKELY FILTER INTO THE INLAND
EMPIRE SOME TIME AFTER 04Z MON. BASES WILL RISE BEGINNING AROUND 11Z
AS THE OFFSHORE WINDS KICK IN, TO AROUND 1600-2000FT MSL OR HIGHER.
CLOUDS SHOULD CLEAR TO THE COAST BY 18Z MON.
MOUNTAINS/DESERTS
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF
PERIOD. STRONG SURFACE WINDS GUSTING 25-35 KT, UP TO 45 KT THROUGH
WIND-PRONE PASSES, AT TIMES IN THE DESERTS AND EASTERN MOUNTAIN
SLOPES, GENERALLY AFTER 18Z TODAY, PREVAILING THROUGH THE EVENING.
MODERATE UP/DOWNDRAFTS EXPECTED IN THE VICINITY OF THE MOUNTAINS.
WINDS BECOMING OFFSHORE AND BREEZY AFTER 12Z MONDAY MORNING FOR THE
WEST MTN FOOTHILLS LOCALLY INTO EASTERN VALLEYS, WITH LOCAL AREAS OF
LLWS POSSIBLE FOR PARTS OF THE VALLEYS.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH FRIDAY.
SGX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...NONE.
PUBLIC...MUNYAN
AVIATION/MARINE...ZUBER
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