978
FXUS66 KSGX 161809
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1109 AM PDT FRI OCT 16 2026
SYNOPSIS
SANTA ANA WINDS WILL CONTINUE THROUGH SATURDAY, WITH THE STRONGEST
WINDS EXPECTED TODAY. HOT AND DRY CONDITIONS EXPECTED FOR THE
COASTAL BASIN WITH MODERATE TO LOCALLY MAJOR HEATRISK FOR COASTAL
AREAS. SANTA ANA WINDS WEAKEN BY SUNDAY, ALLOWING THE COASTAL BASIN
TO COOL OFF. FURTHER COOLING EXPECTED REGION-WIDE FOR NEXT WEEK WITH
WIDESPREAD RAIN AS A LOW PRESSURE SYSTEM MOVES IN FROM THE
NORTHWEST.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
..UPDATED AVIATION DISCUSSION
UPPER-LEVEL NORTHEASTERLY FLOW HAS COMBINED WITH A STRONG OFFSHORE
SURFACE PRESSURE GRADIENT TO PRODUCE MODERATE TO LOCALLY STRONG
SANTA ANA WINDS. THUS FAR, THE WINDS HAVE BEEN PRIMARILY OUT OF THE
NORTHEAST WITH THE TYPICALLY WINDY CORRIDORS NORTH OF SAN DIEGO
COUNTY BEING MORE FAVORED. UPPER LEVEL WINDS WILL TURN DUE EAST
ACROSS THE REGION THIS MORNING AS AN UPPER CUT-OFF LOW MOVES TO THE
SOUTH. CONCURRENTLY, THE STRONG SURFACE HIGH OVER THE NORTHERN
PLAINS WILL MIGRATE SOUTHWARD OVER THE NEXT DAY. AS A RESULT, WINDS
WILL TURN EASTERLY AND STRENGTHEN IN FAVORED ZONES (SAN DIEGO
COUNTY, SOUTHERN OC, AND THE EASTERN INLAND EMPIRE) AND WEAKEN
SLIGHTLY ELSEWHERE.
WIND GUSTS TODAY WILL PEAK AROUND 50-65 MPH ALONG COASTAL SLOPES AND
ADJACENT FOOTHILLS (LOCALLY HIGHER FOR EAST-FACING SLOPES AND
DOWNWIND OF THE BANNING PASS). FOR THE VALLEY, CORRIDORS OF WIND
GUSTS 35-55 MPH EXPECTED, ESPECIALLY IN EASTERN SAN DIEGO COUNTY.
WINDS SLOWLY WEAKEN TONIGHT INTO SATURDAY AS THE EASTERLY FLOW ALOFT
AND THE SURFACE PRESSURE GRADIENT BOTH WEAKEN. GUSTS ON SATURDAY ARE
EXPECTED TO PEAK AROUND 40-55 MPH ALONG COASTAL SLOPES AND FOOTHILLS
(LOCALLY HIGHER FOR EAST-FACING SLOPES. CORRIDORS OF GUSTS 30-45 MPH
WILL CONTINUE FOR THE VALLEYS. SANTA ANA WINDS WEAKEN FURTHER
SATURDAY NIGHT AND DIMINISH ENTIRELY BY SUNDAY.
ELEVATED TO NEAR-CRITICAL FIRE WEATHER CONDITIONS WILL CONTINUE
THROUGH SATURDAY, THOUGH RELATIVE HUMIDITY VALUES WILL BE SLIGHTLY
HIGHER THAN THEY WERE ON THURSDAY. SOME INFLUX OF MOISTURE FROM THE
SOUTH WILL KEEP RH VALUES MAINLY ABOVE 15% THROUGH THE REMAINDER OF
THE EVENT. IN FACT, THERE IS A SLIGHT CHANCE OF LIGHT SHOWERS FOR
SOUTHERN SAN DIEGO COUNTY SATURDAY MORNING, THOUGH THERE IS AN EVEN
LOWER CHANCE (5-10%) FOR ANY WETTING RAINFALL.
LOOKING FORWARD TO NEXT WEEK, THE RETURN OF ONSHORE FLOW ON MONDAY
WILL BRING COOLER WEATHER FOR THE COASTAL BASIN. PATCHY FOG IS
EXPECTED MON/TUE MORNINGS AS THE MARINE LAYER REBUILDS ITSELF.
MODELS CONTINUE TO BECOME BETTER ALIGNED REGARDING THE STRENGTH AND
TRACK OF A ROBUST UPPER-LOW PRESSURE SYSTEM EXPECTED TO SWING
THROUGH THE REGION MID-NEXT WEEK. THIS WILL BRING A WIDESPREAD
COOLING TREND STARTING NEXT TUESDAY AND WIDESPREAD PRECIPITATION
NEXT WED-THU. PRECIPITATION WILL LIKELY REMAIN LIGHT TO MODERATE DUE
TO LACK OF ANY NOTABLE MOISTURE SOURCE, THOUGH MODEL GUIDANCE HAS
TRENDED WETTER SINCE YESTERDAY. THERE IS STILL SOME DISAGREEMENT ON
PRECIPITATION AMOUNTS AND EXTENT OF COOLING AT THIS TIME. ELEVATED
WINDS ARE ALSO EXPECTED FOR MOUNTAINS, DESERTS, AND COASTAL WATERS.
MODEL SOLUTIONS DIVERGE BY NEXT WEEKEND, THOUGH THE MEAN OF THE
GUIDANCE LEANS SLIGHTLY TOWARD UPPER TROUGHING.
AVIATION
161800Z...NORTHEAST TO EAST WINDS STRONGEST THROUGH AND BELOW
FOOTHILLS GUSTING 30-50 KTS, LOCALLY 60 KTS. THIS WILL CAUSE MOD-STG
DOWNDRAFTS IN LEE (SOUTH AND WEST) OF MOUNTAINS, ALONG WITH AREAS OF
LLWS. WINDS WILL GRADUALLY WEAKEN AFTER 00Z, BUT CONTINUE WITH A
SLIGHTLY MORE EASTERLY DIRECTION. MORE WEAKENING EXPECTED SATURDAY
AFTER 11Z.
OTHERWISE...SCT HIGH CLOUDS AND VFR CONDITIONS EXPECTED THROUGH THIS
EVENING, WITH INCREASING CLOUDS ABOVE 10 KFT ESPECIALLY NEAR MEXICO.
MARINE
ISOLATED NORTHEAST GUSTS COULD EXCEED 20 KNOTS TODAY INTO EARLY
SATURDAY. OTHERWISE, NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED
THROUGH TUESDAY.
BEACHES
A SOUTH SWELL INCREASING SUNDAY AND MONDAY WILL BRING ELEVATED SURF
OF 3 TO 5 FEET WITH SETS TO 7 FEET FOR MONDAY AND TUESDAY. WHILE
SURF AND RIP CURRENTS WILL BE ELEVATED, HIGH TIDES WILL NOT BE
PARTICULARLY HIGH, AND THE THREAT OF COASTAL FLOODING IS MINIMAL.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...HEAT ADVISORY UNTIL 8 PM PDT SATURDAY FOR ORANGE COUNTY COASTAL
AREAS-ORANGE COUNTY INLAND AREAS-SAN DIEGO COUNTY COASTAL
AREAS.
HIGH WIND WARNING UNTIL 8 PM PDT SATURDAY FOR SAN BERNARDINO AND
RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO COUNTY
VALLEYS.
HIGH WIND WARNING UNTIL 8 PM PDT THIS EVENING FOR SAN BERNARDINO
COUNTY MOUNTAINS.
HIGH WIND WARNING UNTIL MIDNIGHT PDT SATURDAY NIGHT FOR
RIVERSIDE COUNTY MOUNTAINS-SAN DIEGO COUNTY MOUNTAINS-SAN
GORGONIO PASS NEAR BANNING.
HIGH WIND WARNING UNTIL NOON PDT SATURDAY FOR SANTA ANA
MOUNTAINS AND FOOTHILLS.
WIND ADVISORY UNTIL NOON PDT SATURDAY FOR ORANGE COUNTY INLAND
AREAS.
PZ...NONE.
PUBLIC...KW
AVIATION/MARINE/BEACHES...MM
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