226
FXUS66 KSGX 160933
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
233 AM PDT SAT MAY 16 2026
SYNOPSIS
COOLER FOR THIS WEEKEND, ESPECIALLY FOR INLAND AREAS WITH
STRONGER ONSHORE FLOW. THE MARINE LAYER WILL DEEPEN DURING THE
WEEKEND WITH NIGHT AND MORNING COASTAL LOW CLOUDS EXTENDING WELL
INLAND AND ONTO THE COASTAL SLOPES OF THE MOUNTAINS. FOR SATURDAY
AFTERNOON INTO SUNDAY EVENING, SOUTHWEST TO WEST WINDS FOR THE
MOUNTAINS AND DESERTS WILL GUST TO 40 TO 50 MPH, WITH ISOLATED
GUSTS TO 65 MPH. THE COAST AND VALLEYS WILL WARM ON MONDAY WITH
THE GREATER WARMING FOR INLAND AREAS FOR TUESDAY THROUGH
WEDNESDAY, FOLLOWED BY A SLIGHT COOLDOWN FROM THURSDAY INTO
FRIDAY.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
TODAY THROUGH TOMORROW NIGHT...
AN "INSIDE SLIDER" TYPE MAJOR SHORTWAVE TROUGH IS GOING TO DEEPEN
AND PROPAGATE OVER THE DESERT SOUTHWEST, WHICH WILL RESULT IN A
TIGHTENING OF THE SURFACE GRADIENT AND ALLOW FOR WINDS TO BECOME
RATHER STRONG AND GUSTY OVER THE HIGHER TERRAIN, AND THROUGH THE
MOUNTAIN CANYONS, WHERE WINDS WILL BE SUSTAINED UP AROUND 40 TO 50
MPH BY LATER THIS AFTERNOON FOR WIND-PRONED AREAS. THERE COULD ALSO
BE SOME ISOLATED GUSTS APPROACHING 65 TO 70 MPH FOR THE WINDIEST
AREAS. THERE COULD BE SOME AREAS OF BLOWING DUST, AND ESPECIALLY
WITHIN THE COACHELLA VALLEY. FOR THE HIGH DESERTS, AS MIN RH VALUES
DROP INTO THE LOW TEENS BY LATER THIS AFTERNOON, WITH STRONG AND
GUSTY WINDS, CONDITIONS WILL BE FAVORABLE FOR FIRE GROWTH AND
SPREAD, ALTHOUGH FUELS ARE NOT YET CRITICAL FOR THESE AREAS. ONSHORE
FLOW WILL ALSO BECOME MORE ENHANCED, LEADING TO A MORE PERSISTENT
MARINE LAYER, WHICH WILL LIKELY REMAIN RATHER PREVALENT FOR THE
COASTAL AREAS. TEMPERATURES WILL ALSO BE ON THE COOLER SIDE WITH
SOME REINFORCEMENT OF COLDER AIR BEHIND THIS TROUGH AS IT PASSES
OVER THE REGION, WITH HIGHS BEING SLIGHTLY BELOW THE SEASONAL
AVERAGE FOR THIS TIME OF YEAR, ESPECIALLY FOR THE INLAND VALLEYS,
WHERE HIGHS WILL BE AS MUCH AS 10 DEGREES BELOW AVERAGE FOR SOME
LOCATIONS. GIVEN THE TRACK OF THIS SYSTEM, IT SHOULD REMAIN DRY,
ONLY PERHAPS A FEW AREAS OF DRIZZLE WILL BE POSSIBLE AGAINST THE
COASTAL SLOPES, OTHERWISE JUST COOLER AND MORE BREEZY THROUGHOUT THE
WEEKEND.
MONDAY THROUGH FRIDAY...
AFTER PASSAGE OF THE TROUGH MOVING THROUGH THIS WEEKEND, HIGH
PRESSURE IS GOING TO BUILD BACK IN BEHIND IT, WITH DIMINISHING WINDS
SWITCHING TO A WEAK OFFSHORE FLOW ALOFT RETURNING THROUGH THE EARLY
PART OF THE WEEK. THIS WILL RESULT IN GRADUAL WARMING THROUGH
WEDNESDAY BEFORE THE LONGWAVE PATTERN BECOMES MORE ZONAL WITH ONLY
WEAK RIDGING ALOFT GOING INTO THE LATTER HALF OF THE WEEK. THIS WILL
GIVE WAY TO THE APPEARANCE OF THE MORE COMMON "MAY GREY" DIURNAL
PATTERN, WITH BETTER COVERAGE AT THE COAST THROUGHOUT THE DAY, AND
TEMPERATURES SLOWLY COOLING OFF FROM THURSDAY INTO FRIDAY. DRY
CONDITIONS LOOK TO ALSO PERSIST THROUGH NEXT WEEK.
AVIATION
161000Z...COAST/VALLEYS...LOW CLOUDS BASED 2000-2500FT MSL HAVE
SUCCESSFULLY MADE IT 25+ MILES INLAND AND PUSHED UP AGAINST THE
MOUNTAINS. MINOR VIS REDUCTIONS (3-5SM) EXPECTED FOR SOME ELEVATED
INLAND VALLEYS, WITH LOWER VIS WHERE CLOUDS INTERSECT TERRAIN. VERY
PATCHY -DZ POSSIBLE FROM 12-17Z. SLOW CLEARING EXPECTED WITH
SCATTERING OCCURRING 17-20Z FOR INLAND AREAS. AREAS NEAR THE
COASTLINE, ESPECIALLY FOR SAN DIEGO COUNTY, MAY STAY BKN THROUGH THE
AFTERNOON (40-50% CHANCE). LOW CLOUDS BASED 2000-3000 FT MSL WILL
QUICKLY MOVE INLAND AGAIN THIS EVENING, STARTING IN SAN DIEGO COUNTY
AND MOVING NORTHWARD OVERNIGHT, POTENTIALLY AS EARLY AS 22-23Z.
MOUNTAINS/DESERTS...ELEVATED WESTERLY WIND GUSTS WILL CONTINUE
THROUGH THIS MORNING WITH 25-35 KT GUSTS WIDESPREAD. GUSTS LOCALLY
TO 45 KTS ALONG WIND PRONE DESERT SLOPES AND THROUGH MOUNTAIN
PASSES. MOD UP/DOWNDRAFTS AND LOCAL LLWS IN LEE OF MOUNTAINS. WINDS
STRENGTHEN FURTHER THIS AFTERNOON WITH GUSTS 35-45 KTS WIDESPREAD,
LOCALLY TO 60 KTS IN WIND PRONE LOCATIONS. WINDS REMAIN GUSTY
THROUGH SUNDAY. STRONG UP/DOWNDRAFTS IN LEE OF MTNS WITH BLDU AND
REDUCED VIS EXPECTED. OTHERWISE, SKC AND VFR EXPECTED THROUGH THE
PERIOD.
MARINE
GUSTY WESTERLY WINDS WITH GUSTS 20-30 KT WILL DEVELOP IN THE OUTER
COASTAL WATERS LATE THIS AFTERNOON. THE STRONGEST GUSTS WILL OCCUR
NEAR SAN CLEMENTE ISLAND. SEAS OF 7-10 FEET WITH A 9-12 SECOND
PERIOD WILL GENERATE CHOPPY SEAS. WINDS AND SEAS WILL SLOWLY
DIMINISH THROUGH THE DAY SUNDAY. A SMALL CRAFT ADVISORY IS IN EFFECT
AND CONTAINS MORE INFORMATION.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...BEACH HAZARDS STATEMENT FROM THIS EVENING THROUGH MONDAY MORNING
FOR ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL
AREAS.
WIND ADVISORY FROM 11 AM THIS MORNING TO 11 PM PDT SUNDAY FOR
APPLE AND LUCERNE VALLEYS-SAN BERNARDINO COUNTY MOUNTAINS.
WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 11 PM PDT SUNDAY FOR
RIVERSIDE COUNTY MOUNTAINS-SAN DIEGO COUNTY DESERTS-SAN
DIEGO COUNTY MOUNTAINS-SAN GORGONIO PASS NEAR BANNING.
PZ...SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 7 AM PDT SUNDAY
FOR WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER
EXTENDING 10 TO 60 NM OUT INCLUDING SAN CLEMENTE ISLAND.
PUBLIC...STEWEY
AVIATION/MARINE...ZUBER
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