164
FXUS66 KSGX 090510
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
910 PM PST THU JAN 8 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
INTO NEXT WEEK. PATCHY FROST ARE POSSIBLE IN WIND SHELTERED
VALLEY LOCATIONS IN SAN DIEGO COUNTY AND THE EASTERN INLAND EMPIRE
TONIGHT INTO EARLY FRIDAY MORNING. WARM DAYS WEST OF THE
MOUNTAINS CAN BE EXPECTED FRIDAY INTO EARLY NEXT WEEK.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
KEY POINTS:
* MODERATE TO LOCALLY STRONG SANTA ANA WINDS ARE EXPECTED TONIGHT
INTO FRIDAY FOR PORTIONS OF ORANGE COUNTY, INLAND EMPIRE, AND
COASTAL SLOPES OF THE SAN BERNARDINO COUNTY MOUNTAINS, EXPANDING
TO SAN DIEGO COUNTY VALLEYS AND COASTAL MOUNTAIN SLOPES FRIDAY.
* SANTA ANA WINDS WILL CONTINUE ACROSS ALL VALLEYS, FOOTHILLS,
AND COASTAL MOUNTAIN SLOPES INTO NEXT WEEK. WINDS FOR THE FIRST
HALF OF NEXT WEEK LOOK WEAKER THAN THE WEEKEND, WITH LOWER
CONFIDENCE IN WINDS FOR THE SECOND HALF OF THE WEEK.
* COLD MORNINGS AND PATCHY FROST ARE EXPECTED FRIDAY THROUGH
SUNDAY FOR THE DESERTS AND WIND SHELTERED VALLEYS.
EVENING UPDATE...
SURFACE PRESSURE GRADIENTS ARE TRENDING OFFSHORE THIS EVENING,
CURRENTLY AROUND -7.2 MB SAN-TPH AND -2.2 SAN-DAG. MID-LEVEL WINDS
WERE STILL NORTHWESTERLY BASED ON THE 00Z KNKX SOUNDING, BUT ARE
FORECAST TO VEER AROUND TO NORTHERLY/NORTHEASTERLY TONIGHT AS THE
UPPER LEVEL LOW PROGRESSES EASTWARD. THIS ADDED UPPER LEVEL
SUPPORT AND INCREASING SURFACE PRESSURE GRADIENTS WILL DRIVE
MODERATELY TO LOCALLY STRONG NORTH-NORTHEAST WINDS, ESPECIALLY
NEAR THE FOOTHILLS OF THE SAN BERNARDINO MOUNTAINS, BELOW THE
CAJON PASS, AND INTO THE SANTA ANA MOUNTAINS. WINDS ARE EXPECTED
TO PEAK TONIGHT INTO FRIDAY MORNING FOR THESE AREAS WITH WIND
GUSTS OF 60-65 MPH OR MORE IN THE WIND-PRONE PASSES AND CANYONS.
FOR THE REMAINING PORTIONS OF THE INLAND EMPIRE AND INLAND ORANGE
COUNTY, GUSTS WILL BE CLOSER TO 35-50 MPH.
PATCHY FROST IS ALSO POSSIBLE TONIGHT FOR THE WIND SHELTERED
VALLEYS, MAINLY IN THE SOUTHEASTERN INLAND EMPIRE AND WESTERN
VALLEYS OF SAN DIEGO COUNTY. GIVEN THE SOMEWHAT ISOLATED NATURE
AND LOW CONFIDENCE IN WINDS DYING DOWN ENOUGH, HELD OFF ON ISSUING
ANY FROST ADVISORIES FOR NOW.
PREVIOUS DISCUSSION...
WINDS WILL BECOME MORE NORTHEAST TO EAST FRIDAY THROUGH THE WEEKEND
AS THE MAIN DRIVER OF THE SANTA ANAS BECOMES THE PRESSURE GRADIENT
BETWEEN SOUTHERN CALIFORNIA AND THE INTERMOUNTAIN WEST. THIS WILL
SPREAD MODERATE STRENGTH NORTHEAST TO EAST SANTA ANA WINDS TO THE
SAN DIEGO MOUNTAIN FOOTHILLS, LOCALLY INTO THE VALLEYS. AS THE WINDS
BECOME MORE NORTHEAST TO EAST IN DIRECTION, WINDS PREVIOUSLY
MENTIONED IN PLACES NORTH OF SAN DIEGO COUNTY WILL WEAKEN, BUT
REMAIN ELEVATED. OVERALL PEAK GUSTS OF 35-55 MPH, LOCALLY UP TO 65
MPH, ARE EXPECTED FRIDAY AFTERNOON THROUGH SUNDAY FROM THE VALLEYS
TO THE COASTAL MOUNTAIN SLOPES. THE STRONGEST WINDS WILL OCCUR ON
THE COASTAL SLOPES OF THE MOUNTAINS INTO THE FOOTHILLS AND BELOW
PASSES. PERIODS OF SANTA ANA WINDS ARE EXPECTED TO CONTINUE INTO
NEXT WEEK BUT CURRENT GUIDANCE IS INDICATING WINDS WILL BE WEAKER
FOR THE FIRST HALF OF THE WEEK. THERE REMAINS UNCERTAINTY IN THE
WIND SPEEDS FOR THE SECOND HALF.
A VERY COLD AIRMASS WILL BE TRANSPORTED INTO OUR AREA DESERTS,
MOUNTAINS, AND WIND SHELTERED VALLEYS. COLDEST CONDITIONS ARE
EXPECTED TONIGHT INTO FRIDAY MORNING FOR AREAS WEST OF THE
MOUNTAINS, WITH COLD CONDITIONS FOR THE DESERTS AND MOUNTAINS
CONTINUING INTO THE WEEKEND. FROST IS POSSIBLE IN WIND SHELTERED
VALLEY LOCATIONS OVERNIGHT TONIGHT, MOST LIKELY IN THE INLAND EMPIRE
SOUTH OF I-10 AND EAST OF I-215 AND EAST OF I-15 IN SAN DIEGO
COUNTY. ALTHOUGH NIGHTS WILL BE CHILLY FOR THE NEXT FEW DAYS, A
GRADUAL WARMING TREND IS EXPECTED THROUGH NEXT WEEK. BY EARLY NEXT
WEEK, HIGHS WEST OF THE MOUNTAINS WILL REACH THE MID TO UPPER 70S,
WITH HIGHS REACHING THE 80S FOR SOME LOCATIONS BY THE END OF THE
WEEK. FROM FRIDAY ONWARD, MARINE LAYER LOW CLOUDS AND FOG ARE
EXPECTED TO BE ABSENT FROM COASTAL AREAS DUE TO THE DOMINATE
OFFSHORE FLOW.
AVIATION
090430Z...FEW CLOUDS WITH BASES 3500-4500 FT MSL DISSIPATING
OVERNIGHT.
NORTH TO NORTHEAST WINDS GUSTING 25-35 KTS ALONG NORTHEASTERN
PORTIONS OF THE INLAND EMPIRE NOW SPREADING TO AREAS OF ORANGE
COUNTY. FOR THESE LOWLAND AREAS, PERIODS OF GUSTS 30-40 KTS (LOCALLY
HIGHER) ARE POSSIBLE THROUGH FRIDAY AFTERNOON. MOD/STG UDDFS
EXPECTED FOR THE WESTERN/SOUTHERN FOOTHILLS OF MOUNTAINS AND PASSES.
IN THE MOUNTAINS, NE WINDS CONTINUE TO STRENGTHEN AND PERIODS OF
GUSTS REACHING 45-55 KTS EXPECTED ALONG ALL SOUTHWEST FACING
MOUNTAINS SLOPES AND RIDGES THROUGH EARLY FRIDAY AFTERNOON. EAST
WINDS WILL ALSO STRENGTHEN TO 35-45 KTS THROUGH THE BANNING PASS AND
ALONG SD CO. MTNS AFTER 15Z.
MARINE
GUSTS TO 25 KNOTS IN THE OUTER WATERS AND GUSTS AROUND 20 KTS WITHIN
10 MILES OF THE COAST WILL WEAKEN BY 10 PM.
ADDITIONALLY, COMBINED SEAS OF 9 TO 11 FEET WITH AN 8-9 SECOND
PERIOD (PROVIDING LOCALLY STEEP WAVES) WILL DECREASE TONIGHT.
A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH 10 PM AND CONTAINS
MORE DETAILS. AFTER TODAY, NO HAZARDOUS MARINE CONDITIONS EXPECTED
THROUGH THIS WEEKEND.
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 RIVERSIDE COUNTY
MOUNTAINS-SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE
INLAND EMPIRE-SAN DIEGO COUNTY MOUNTAINS-SAN GORGONIO PASS
NEAR BANNING.
WIND ADVISORY FROM 8 AM FRIDAY TO 1 PM PST SUNDAY FOR SAN DIEGO
COUNTY VALLEYS.
HIGH WIND WARNING UNTIL 1 PM PST SUNDAY FOR SAN BERNARDINO
COUNTY MOUNTAINS.
WIND ADVISORY UNTIL 1 PM PST SUNDAY FOR SANTA ANA MOUNTAINS AND
FOOTHILLS.
WIND ADVISORY UNTIL 1 PM PST SATURDAY FOR ORANGE COUNTY INLAND
AREAS.
PZ...SMALL CRAFT ADVISORY UNTIL 10 PM PST THIS EVENING FOR COASTAL
WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER AND OUT
TO 10 NM-WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER
EXTENDING 10 TO 60 NM OUT INCLUDING SAN CLEMENTE ISLAND.
PUBLIC...SS
AVIATION/MARINE...PG
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