434
FXUS66 KSGX 201735
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
935 AM PST THU FEB 20 2025
SYNOPSIS
WARMER DAYS WILL CONTINUE INTO THE WEEKEND WITH WEAK SANTA ANA
WINDS MOVING INTO THE REGION TODAY AND FRIDAY. THIS IS LEADING TO
A SHALLOWER MARINE LAYER THIS MORNING INTO FRIDAY, WHERE PATCHY
LOW CLOUDS WILL BE NEAR THE COAST EACH MORNING. HIGH PRESSURE
ALOFT BECOMES STRONGER BY THE EARLY AND MIDDLE PART OF NEXT WEEK,
LEADING TO EVEN WARMER CONDITIONS WITH HIGHS 10 TO 20 DEGREES
ABOVE NORMAL.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
UPDATE: LOW CLOUDS AND FOG ARE CONTINUING TO MIX OUT, WITH ONLY SOME
PORTIONS OF THE COASTAL AREAS OF SOUTHERN SAN DIEGO COUNTY AND
NORTHERN ORANGE COUNTY STILL SOCKED IN. THERE IS A WEAK COASTAL EDDY
STILL VISIBLE ON SAT IMAGERY DUE WEST OF SAN DIEGO, WHICH MAY ALLOW
FOR SOME OF THE LOW CLOUDS TO STICK AROUND FOR A FEW MORE HOURS WITH
INTERMITTENT BREAKS. THESE LOW CLOUDS WILL CONTINUE TO DISSIPATE AS
ONSHORE WINDS CONTINUE TO WEAKEN AND EVENTUALLY SWITCH AROUND TO A
WEAK OFFSHORE WIND BY LATER IN THE DAY. SOME LOW CLOUDS AND PATCHY
FOG WILL BE PRESENT AGAIN RIGHT ALONG THE COASTAL AREAS BY LATER
THIS EVENING AND THROUGH TOMORROW MORNING, ALTHOUGH THIS WILL BE
MORE LIMITED (AND MOSTLY NON-EXISTENT FOR THE INLAND VALLEYS) DUE
TO WEAK OFFSHORE WINDS REMAINING IN PLACE.
DETERMINISTIC AND ENSEMBLE MODELS ALIKE STILL REMAIN IN AGREEMENT
WITH THE BUILDING IN OF A STRONG RIDGE THIS WEEKEND, LEADING TO VERY
WARM AND ABOVE AVERAGE TEMPERATURES EXPECTED THROUGHOUT THE MIDDLE
OF NEXT WEEK.
(PREVIOUS DISCUSSION SUBMITTED AT 133 AM)
SURFACE LEVEL WINDS ARE BEGINNING TO TURN WEAKLY OFFSHORE THIS
MORNING FOR INLAND AREAS AS LOW CLOUDS SUBTLY INCREASE IN COVERAGE
NEAR THE BEACHES. CLOUDS WILL CONTINUE TO BE INTERMITTENT NEAR THE
COAST, BUT WHEREVER CLOUDS DO FORM, PATCHY FOG CAN BE EXPECTED
THROUGH MID-MORNING. SANTA ANA WINDS FROM THE NORTH AND NORTHEAST
WILL INCREASE INTO THE AFTERNOON. CONFIDENCE IS MODERATE TO HIGH
IN SEEING WINDS OVER 35 MPH BELOW PASSES/CANYONS ACROSS PARTS OF
INLAND ORANGE COUNTY AND THE INLAND EMPIRE BY THIS AFTERNOON.
WINDS WILL STILL BE OFFSHORE TONIGHT, WEAKENING SLIGHTLY, THEN
INCREASING BY FRIDAY AFTERNOON, THOUGH NOT AS STRONG AS TODAY'S
WINDS. AS THE OFFSHORE WINDS MOVE OVER OUR REGION, DOWNSLOPE
WARMING WILL OCCUR, LEADING TO HIGHER TEMPERATURES ACROSS THE
LOWER ELEVATIONS. HIGHS WERE RAISED A FEW DEGREES FROM NBM TO
ACCOUNT FOR THIS LARGELY ABOVE AVERAGE WARMING. CONFIDENCE OF
INLAND VALLEYS WEST OF THE MOUNTAINS REACHING 80 DEGREES IS LOWER
TODAY BUT HIGHER BY FRIDAY AFTERNOON. AS IS TYPICAL WITH THIS WIND
PATTERN, PASSES AND CANYONS WHERE WINDS BLOW THROUGH THE NIGHT
WILL SEE WARMER LOW TEMPS THAN THOSE IN WIND-SHELTERED VALLEYS.
WINDS TURN WEAKER BY THE WEEKEND AND INTO NEXT WEEK AS HIGH
PRESSURE MAINTAINS ITS PRESENCE OVER THE AREA, CONTINUING THE
WARM AND DRY WEATHER PATTERN. MODELS SUGGEST THIS RIDGE OF HIGH
PRESSURE AMPLIFYING OVER THE WESTERN U.S. BY TUESDAY AND
WEDNESDAY. THIS WOULD BRING FURTHER WARMING TO THE REGION WITH
HIGHS POSSIBLY REACHING OVER 90 DEGREES ACROSS THE COACHELLA
VALLEY AND OVER 85 DEGREES FOR SOME VALLEYS WEST OF THE MOUNTAINS.
THIS WARMTH LOOKS TO BE SHORT-LIVED AS MODELS INDICATE AN AREA OF
LOW PRESSURE EXPECTED TO MOVE SOMEWHERE IN OUR VICINITY FROM OFF
THE COAST, WHICH WILL AID TO BRING IN COOLER WEATHER BY THE END
OF NEXT WEEK.
AVIATION
201630Z...COAST...VERY PATCHY LOW CLOUDS/FG ALONG THE COAST,
SPECIFICALLY IN FAR SOUTH SAN DIEGO COUNTY AND FAR NORTH ORANGE
COUNTY. VIS OF 1/4-1SM FOR ANY LOCATION WITH FG. BASES AROUND 200-
400FT MSL. CLEARING WILL CONTINUE THROUGH 18Z, WITH COMPLETE
CLEARING EXPECTED BY 19Z WITH DRIER AIR MOVING IN. AREAS OF FG COULD
REMAIN ALONG THE IMMEDIATE BEACHES THROUGH THE EARLY AFTERNOON.
MOSTLY CLEAR SKIES FOLLOWING EXCEPT FOR OCCASIONAL FEW-SCT HIGH
CLOUDS THROUGH LATE THIS EVENING. LOW CLOUDS LOOK TO REDEVELOP AFTER
08-09Z FRI, BUT WILL BE EVEN MORE ISOLATED, WITH THE GREATEST
CHANCES FOR IMPACTS (60% CHANCE) IN SOUTHERN SAN DIEGO COUNTY 09-14Z
FRI, CLEARING AROUND 15Z. BASES AND VIS WOULD BE SIMILAR TO THIS
MORNING FOR THE LIMITED AREAS THAT DO SEE FG/LOW CLOUDS.
VALLEYS/MOUNTAINS/DESERTS...FEW-SCT HIGH CLOUDS ABOVE 25,000 FT MSL
AND VFR CONDITIONS TODAY AND TOMORROW. NORTH-NORTHEAST TO EASTERLY
WINDS WILL STRENGTHEN OVER MOUNTAINS AND FOOTHILLS/IN DESERTS AND
PARTS OF THE INLAND EMPIRE (GENERALLY AREAS BELOW/SOUTH OF THE CAJON
PASS) EARLY THIS AFTERNOON, REMAINING INTERMITTENTLY GUSTY THROUGH
THE PERIOD. GUSTS TO 25-40 KTS AND MOD UP/DOWNDRAFTS NEAR AND OVER
MOUNTAINS.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE ANTICIPATED THROUGH SATURDAY.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...NONE.
UPDATE...STEWEY
PUBLIC...APR
AVIATION/MARINE...ZUBER
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