727
FXUS66 KSGX 092135
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
135 PM PST FRI JAN 9 2026
SYNOPSIS
MODERATE TO LOCALLY STRONG SANTA ANA WINDS WILL CONTINUE ALONG
THE COASTAL MOUNTAIN SLOPES, FOOTHILLS, AND INTO THE VALLEYS
THROUGH SUNDAY. PERIODS OF WEAKER SANTA ANA WINDS WILL CONTINUE
BEYOND THAT. PATCHY FROST IS EXPECTED THIS MORNING IN WIND
SHELTERED VALLEY LOCATIONS. A WARMING TREND DEVELOPS THIS WEEKEND,
WITH TEMPERATURES PEAKING AROUND THE MIDDLE OF NEXT WEEK.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
..UPDATED AVIATION AND MARINE SECTIONS
IN ORANGE COUNTY, NORTHEAST WIND GUSTS BETWEEN 25-45 MPH ARE BEING
OBSERVED FROM THE SANTA ANA MOUNTAIN FOOTHILLS DOWN TO THE COAST
LOCALLY. GUSTS OF 55-65 MPH ARE SEEN IN THE SOUTHWEST FACING
CANYONS, LOCALLY UP TO 76 MPH IN FREMONT CANYON. AREAS SOUTH OF THE
CAJON PASS CONTINUE TO SEE GUSTS BETWEEN 40-55 MPH WITH AREAS
GUSTING AS HIGH AS 88 MPH ALONG ELEVATED TERRAIN AT THE EXIT OF THE
PASS. THESE ARE EXPECTED TO BE THE STRONGEST GUSTS ACROSS THE REGION
FOR WHAT IS EXPECTED TO BE A PROLONGED WEAK SANTA ANA WIND EVENT
THROUGH AT LEAST MONDAY. THE 700-500 MB NORTHWESTERLY WINDS WILL
MOVE EASTWARD TONIGHT ALONG WITH THE JET STREAM, MAKING THE SURFACE
PRESSURE GRADIENT THE SOLE DRIVER OF THE OFFSHSORE FLOW AND BRINGING
US DOWN TO WEAK BUT ELEVATED SANTA ANA WIND LEVELS. THE CW3E WEST
WRF KEEPS US ABOVE 60% CHANCES FOR WEAK SANTA ANA WINDS SATURDAY
THROUGH AT LEAST NEXT WEDNESDAY. DURING THIS PERIOD, EXPECT PERIODS
OF ELEVATED NORTH/NORTHEAST WINDS SUSTAINED AT 15-25 MPH IN THE WIND
PRONE LOWLAND AREAS WITH GUSTS 25-40 MPH. FOR THE COASTAL FOOTHILLS
AND MOUNTAINS, EXPECT PERIODS OF WINDS SUSTAINED AT 25-40 MPH WITH
GUSTS 50-65 MPH. WINDS AND GUSTS MAY TICK DOWN A FEW MPH MID-WEEK AS
THE SURFACE GRADIENT BETWEEN THE GREAT BASIN AND SOUTHERN CALIFORNIA
WEAKENS A BIT BUT REMAIN OFFSHORE INDEFINENTLY UNTIL A GREATER
PATTERN CHANGE OCCURS.
AS LONG AS THE OFFSHORE FLOW PRESISTS, RELATIVE HUMIDITY WILL REMAIN
LOW. DAYTIME RH DROPS INTO THE 10-20% RANGE THIS AFTERNOON AND
SATURDAY AFTERNOON AND CONTINUE TO DROP INTO THE 20-30% RANGE INTO
NEXT WEEK, WITH OVERNIGHT RECOVERIES CAPPED AT ONLY 35-40% IN THE
MOUNTAINS. FIRE DANGER WILL BE ELEVATED AS A RESULT ALTHOUGH LIMITED
AS THE FUEL MOISTURE LEVELS ARE HIGH FROM RECENT RAINS.
TEMPERATURES TODAY ARE SLIGHTLY BELOW AVERAGE, IN THE LOW TO MID 60S
IN THE LOWLANDS. TEMPERATURES CLIMB 2-5 DEGREES F EACH DAY FROM
TODAY THROUGH WEDNESDAY AS A VERY LONGWAVE RIDGE SLOWLY DEVELOPS
ACROSS THE WESTERN US AND NORTHEAST PACIFIC. WPC MODEL CLUSTERS SHOW
THE RIDGE LIKELY CENTERING OFF THE PACIFIC NORTHWEST THOUGH UPPER
HEIGHTS WILL INCREASE AS A RESULT WELL INTO NORTHERN MEXICO. WITH
DAYTIME HEATING, TEMPERATURES ARE LIKELY (80% CHANCE) TO REACH ABOVE
80 DEGREES IN THE VALLEYS NEXT WEDNESDAY AND THURSDAY. NEXT FRIDAY
AND BEYOND, THERE IS MODERATE TO HIGH CONFIDENCE THAT THE RIDGE
REMAINS STRONG OFF OF BRITISH COLUMBIA, ALTHOUGH THERE ARE MODEL
SOLUTIONS SUGGESTING THE POSSIBILITY FOR AN UPPER LOW TO FORM NEAR
OR RETROGRATE INTO THE SOUTHWEST US, WHICH COULD AT THE MIINIMUM
COOL OUR TEMPERATURES BACK CLOSER TO AVERAGE.
AVIATION
092130Z...COAST/VALLEYS/MOUNTAINS...MOSTLY CLEAR SKIES PREVAILING.
NORTHEAST AND EAST WINDS GUSTING 35-50 KTS ALONG COASTAL SLOPES
MOSTLY NORTH OF SAN DIEGO COUNTY. GUSTS 25-35 KTS THROUGH THE INLAND
EMPIRE AND INTO INLAND ORANGE COUNTY. INCLUDING VCTY KONT/KSNA.
EXPANDING IN COVERAGE IN MORE OF SAN DIEGO COUNTY AND MORE OF THE
INLAND VALLEYS AFTER 03Z SAT. PERIODS OF LLWS WITH MOD UDDFS
DOWNWIND OF COASTAL SLOPES (I.E. KONT, KSNA, KSBD). WIND PATTERN
CONTINUES THROUGH MUCH OF SATURDAY.
DESERTS...VFR CONDITIONS THROUGH THE PERIOD. STRONG NORTHEAST WIND
GUSTS STAYING MOSTLY CONFINED TO MOUNTAIN SLOPES, WITH WINDS
GENERALLY BELOW 20 KTS.
MARINE
NORTHEAST TO EAST WINDS WILL OCCASIONALLY GUST TO 20 TO 25 KNOTS
THROUGH THIS WEEKEND. OTHERWISE, NO HAZARDOUS MARINE CONDITIONS
EXPECTED THROUGH TUESDAY NIGHT.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...WIND ADVISORY UNTIL 1 PM PST SUNDAY FOR ORANGE COUNTY INLAND
AREAS-RIVERSIDE COUNTY MOUNTAINS-SAN BERNARDINO AND
RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO COUNTY
MOUNTAINS-SAN DIEGO COUNTY VALLEYS-SAN GORGONIO PASS NEAR
BANNING-SANTA ANA MOUNTAINS AND FOOTHILLS.
HIGH WIND WARNING UNTIL 1 PM PST SUNDAY FOR SAN BERNARDINO
COUNTY MOUNTAINS.
PZ...NONE.
PUBLIC...APR
AVIATION/MARINE...WESTERINK
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