648
FXUS66 KSGX 282109
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
109 PM PST SUN DEC 28 2025
SYNOPSIS
WARMER AND DRIER THROUGH TUESDAY WITH PERIODS OF MODERATE GUSTY
SANTA ANA WINDS. A LOW PRESSURE SYSTEM FROM THE SOUTHWEST, AND
ANOTHER FROM THE GULF OF ALASKA, WILL LIKELY BRING A RETURN OF
PRECIPITATION FOR WEDNESDAY THROUGH NEXT WEEKEND, THOUGH EXACT
TIMING AND PRECIPITATION AMOUNTS ARE STILL UNCERTAIN.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
COOL WITH VARIABLE HIGH CLOUDS THIS AFTERNOON. SFC PRESSURE
GRADIENTS CONTINUE TO TREND OFFSHORE WITH -8.2 MB SAN-TPH AND -4.0
SAN-DAG. IN THE LAST HOUR, THE FAVORED LOCATIONS ARE REPORTING
NORTHEAST TO EAST WINDS GUSTING 35-45 MPH.
A PATTERN OF HIGH PRESSURE TO THE NORTH AND A CLOSED UPPER LOW TO
THE SOUTHWEST WILL BRING WARM AND DRY CONDITIONS WITH PERIODS OF
GUSTY SANTA ANA WINDS THROUGH TUESDAY. THE OFFSHORE FLOW GETS
SOME UPPER LEVEL SUPPORT ON MON AND TUE WITH NORTHEAST WINDS
ALOFT. THE OFFSHORE FLOW WILL LIKELY BE STRONGEST ON TUESDAY,
PRODUCING GUSTY SANTA ANA WINDS IN THE MTNS AND LOWER ELEVATIONS
WEST OF THE MTNS. NORTHEAST TO EAST WINDS GUSTING 35-45 MPH - WITH
LOCAL GUSTS OF 55-60 MPH - WILL BE POSSIBLE IN THE FAVORED
LOCATIONS. TUESDAY WILL ALSO BE THE WARMEST DAY, WITH HIGH TEMPS
IN THE 70S WEST OF THE MTNS AND MOST AREAS SEEING TEMPS NEAR OR
ABOVE SEASONAL AVERAGES. COASTAL AND VALLEY AREAS COULD BE AS MUCH
AS 9 DEGREES ABOVE AVERAGE WHILE THE MTNS AND DESERTS WILL BE
NEAR OR JUST A FEW DEGREES ABOVE. RELATIVE HUMIDITIES COULD FALL
INTO THE TEENS FOR SOME INLAND AREAS MONDAY AND TUESDAY
AFTERNOONS BUT THE RECENT RAINS WILL MITIGATE FIRE WEATHER
CONCERNS.
CHANCES FOR RAIN AND MOUNTAIN SNOW WILL RETURN FOR WED THROUGH
NEXT WEEKEND AS A LOW PRESSURE SYSTEM MOVES IN FROM THE GULF OF
ALASKA, CAUSING THE CLOSED LOW TO OUR SOUTHWEST TO BECOME AN OPEN
WAVE AS IT IS DRAWN INTO THE MEAN WESTERLY FLOW OVER THE SOUTHWEST
US. FORECAST DETAILS ARE STILL UNCERTAIN BUT NUMERICAL MODEL
SOLUTIONS ARE COMING INTO BETTER AGREEMENT WITH RESPECT TO THE
SYNOPTIC PATTERN. CURRENT SOLUTIONS INDICATE THAT SOCAL WILL
RECEIVE PRECIPITATION IN TWO PHASES. THE CLOSED LOW EJECTING TO
THE NORTHEAST FROM ITS POSITION ABOUT 1100 MILES TO OUR SOUTHWEST
WILL LIKELY BRING PERIODS OF RAIN/SHOWERS IN A WARM ENVIRONMENT LATE
WED THROUGH THU. A DYNAMIC RIDGE BETWEEN THE EXITING LOW/TROUGH
AND THE LOW APPROACHING FROM THE GULF OF AK COULD PROVIDE A BREAK
FROM THE PRECIP ON FRIDAY. THE LOW FROM THE GULF OF AK WILL RESUME
THE RAIN/SHOWERS IN A COLDER ENVIRONMENT FOR SAT THROUGH SUN.
PRECIPITATION COULD MOVE IN AS EARLY AS LATE WED MORNING WITH
PERIODS OF RAIN AND SHOWERS CONTINUING (WITH BREAKS) THROUGH NEXT
SUNDAY. PRECIP AMOUNTS WILL BE GREATEST IN THE NORTHERN AREAS
(ORANGE AND SAN BERNARDINO COUNTIES) AND LESS IN SOUTHERN SAN
DIEGO COUNTY. CURRENT RAINFALL ESTIMATES ARE FOR TOTALS OF
1"-1.9" IN THE COASTAL AREAS, 1.2"-2" IN THE INLAND VALLEYS,
0.10"-0.7" IN THE LOW DESERTS, 0.40"-0.9" IN THE HIGH DESERT,
1.3"-3.5" IN THE SAN DIEGO AND RIVERSIDE COUNTY MTNS AND
1.8"-4.5" IN THE SAN BERNARDINO MOUNTAINS. THE SNOW LEVEL WILL
REMAIN ABOVE 8,000 FT THROUGH FRIDAY BEFORE LOWERING TO AROUND
6,500 FT ON SATURDAY. MOST OF THE PRECIPITATION WILL LIKELY FALL
BEFORE NEXT WEEKEND SO SNOWFALL AMOUNTS AT RESORT LEVELS AND BELOW
WILL BE LIMITED.
AVIATION
282100Z...VFR CONDITIONS CONTINUE THROUGH THE TAF PERIOD WITH FEW TO
SCATTERED CLOUDS AROUND 25,000 FT MSL. GUSTY OFFSHORE WINDS OUT OF
THE NORTH TO NORTHEAST WILL CONTINUE TO STRENGTHEN THROUGH THE
AFTERNOON AND EVENING WITH WIND GUSTS UP TO 25-35KTS FOR THE COASTAL
SLOPES OF THE MOUNTAINS, MOUNTAIN PASSES, AND INLAND VALLEYS. WHILE
GUSTS MAY NOT SURFACE AT TERMINALS LIKE KONT OR KSBD UNTIL LATE
TONIGHT OR MONDAY MORNING, GUSTY NORTHERLY WINDS BELOW CAJON PASS
COULD PRODUCE CROSSWINDS ON APPROACH/TAKEOFF WITHIN THE INLAND
EMPIRE THIS AFTERNOON. LLWS MAY BE POSSIBLE, ESPECIALLY LATE
TONIGHT, FOR INLAND EMPIRE AIRPORTS. GUSTS ARE EXPECTED TO
STRENGTHEN TO 35-45 KTS FOR THE COASTAL MOUNTAIN SLOPES AND PASSES
AFTER 00-02Z MONDAY WITH MOD UP/DOWNDRAFTS EXPECTED. STRONG OFFSHORE
WINDS PREVAIL INTO MONDAY EVENING.
MARINE
NO HAZARDOUS MARINE WEATHER CONDITIONS EXPECTED THROUGH SATURDAY.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 1 PM PST TUESDAY FOR
SAN BERNARDINO 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.
PZ...NONE.
PUBLIC...PG
AVIATION/MARINE...VILLAFANE
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page