098
FXUS66 KSGX 211739
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
939 AM PST SAT DEC 21 2024
SYNOPSIS
PATCHY DENSE FOG MAY LINGER ALONG THE IMMEDIATE COAST THROUGH THE
AFTERNOON, WITH HIGH CLOUDS ELSEWHERE. NEAR AVERAGE TEMPERATURES
EXPECTED NEAR THE COAST THROUGH EARLY NEXT WEEK WITH ABOVE AVERAGE
TEMPERATURES AWAY FROM THE COAST. BREEZIER AND COOLER WEATHER IS
EXPECTED FOR TUESDAY, WITH CHANCES OF SHOWERS IN THE AFTERNOON AND
EVENING. DRY WEATHER IS EXPECTED FOR THE MIDDLE TO END OF NEXT
WEEK.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
AT 9 AM PATCHY DENSE FOG WAS STILL BEING OBSERVED ALONG THE
IMMEDIATE COAST IN BOTH ORANGE AND SAN DIEGO COUNTIES.
VISIBILITIES SHOULD CONTINUE TO IMPROVE FOR MOST AREAS THROUGH
THE MORNING, BUT A FEW PATCHES OF DENSE FOG MAY LINGER AT SOME
BEACHES INTO THE AFTERNOON. ONSHORE FLOW IS EXPECTED TO INCREASE
FOR TODAY INTO SUNDAY AS A WEAK TROUGH PASSES TO OUR NORTH. THAT
WILL HELP SPREAD LOW CLOUDS AND FOG FURTHER INLAND TONIGHT INTO
SUNDAY MORNING REACHING INTO PORTIONS OF THE WESTERN VALLEYS WITH
DENSE FOG BECOMING LESS LIKELY FOR THE IMMEDIATE COAST. FOR SAN
DIEGO COUNTY AREAS OF DENSE FOG COULD REACH THE INTERSTATE 15
CORRIDOR AND FOR ORANGE COUNTY BETWEEN INTERSTATE 405 AND
INTERSTATE 5.
HIGHS TODAY WILL REMAIN 5-15 DEGREES ABOVE NORMAL FOR INLAND AREAS;
TEMPERATURES WILL BE IN THE 60S AND 70S FOR AREAS BELOW 5,000 FEET
IN THE MOUNTAINS AND NEAR 80 ACROSS THE COACHELLA VALLEY AND ANZA-
BORREGO DESERT. PERIODS OF HIGH CLOUDS CAN BE EXPECTED TODAY AND
SUNDAY. A FEW DEGREES OF COOLING OR NO CHANGE IN TEMPERATURES IS
EXPECTED FOR SUNDAY. WEAK RIDGING ALOFT WILL MOVE OVER SOUTHERN
CALIFORNIA FOR MONDAY, BRINGING A FEW DEGREES OF WARMING.
ON TUESDAY A QUICK MOVING TROUGH OF LOW PRESSURE WILL MOVE ACROSS
THE WEST COAST. LATEST GUIDANCE IS INDICATING LIGHT RAIN IS POSSIBLE
FROM THE COAST TO THE MOUNTAINS. ONSHORE WESTERLY WINDS WILL
INCREASE TUESDAY AND PEAK TUESDAY NIGHT, STRONGEST IN THE MOUNTAINS,
THROUGH PASSES, AND LOCALLY INTO THE DESERTS. GUIDANCE IS FAIRLY
CONSISTENT ON THE TIMING BEING TUESDAY AFTERNOON AND EVENING FOR
BOTH THE UPTICK IN WIND AND PRECIPITATION. SNOW LEVELS ARE EXPECTED
TO STAY ABOVE 7000 FT DURING THE TIME IT'S PRECIPITATING, WITH SNOW
LEVELS FALLING TO 6500 FT AFTER THE PASSAGE OF THE TROUGH.
OVERALL, RAINFALL TOTALS FOR THE COAST AND VALLEYS ARE EXPECTED
TO BE 0.10" OR LESS, WITH LOCAL AMOUNTS NEAR 0.25" ON THE COASTAL
SLOPES OF THE MOUNTAINS. THE TROUGH IS EXPECTED TO QUICKLY EXIT TO
THE EAST, LEAVING DRY CONDITIONS IN IT'S WAKE FOR MUCH OF
WEDNESDAY.
TEMPERATURES ON WEDNESDAY ARE EXPECTED TO BE NEAR NORMAL FOR THIS
TIME OF YEAR WEST OF THE MOUNTAINS AND 3 TO 7 DEGREE WARMER THAN
NORMAL IN THE DESERTS. LOWER DESERT LOCATIONS WILL HIGHS IN THE 70S
WITH WIDESPREAD 60S WEST OF THE MOUNTAINS. SIMILAR TEMPERATURES CAN
BE EXPECTED THROUGH FRIDAY AS THE TROUGHING PATTERN REMAINS.
CONDITIONS ARE TRENDING DRIER AND WARMER FOR NEXT WEEKEND.
AVIATION
211640Z....COASTS...LOW CLOUDS AND FOG BASED AT 100-300 FEET MSL
WITH TOPS TO 500-600 FT MSL COVERING PARTS OF COASTAL SAN DIEGO AND
ORANGE COUNTIES THIS MORNING, WITH WIDESPREAD VIS AT OR BELOW 1 SM
IN THESE AREAS. CLOUDS ARE BEGINNING TO RETREAT OFFSHORE THIS
MORNING, BUT LIKELY WILL RE-FILL IN TO SOME EXTENT 17-19Z AS WINDS
BECOME MORE ONSHORE. KCRQ LOOKS LIKELY TO CLEAR IN THE NEXT HOUR OR
SO, BUT LOW CLOUDS LOOK LIKELY TO STICK AROUND AT KSAN/KSNA THROUGH
18-19Z. THERE IS A LOW END CHANCE FOR CLOUDS TO HAVE ANOTHER SURGE
INTO SOUTHERN SAN DIEGO COUNTY 19-21Z, BUT LEANING TOWARDS THERE
BEING TOO MUCH SUNLIGHT AT THAT POINT FOR THAT TO FULLY OCCUR WEST
OF THE BEACHES.
MOSTLY CLEAR CONDITIONS EXPECTED THEREAFTER THOUGH SOME PATCHES OF
LOW CLOUDS/FOG COULD LINGER THROUGH THE DAY ALONG THE BEACHES. LOW
CLOUDS AND FOG LOOK TO MAKE A RESURGENCE IN THE EVENING, POSSIBLY AS
EARLY AS 00-01Z, WITH MUCH HIGHER CONFIDENCE IN CIGS AFTER 03-04Z
SUNDAY. CLOUDS WILL REACH FURTHER INLAND OVERNIGHT, UP TO 10-15
MILES FROM THE COAST. BASES AND VIS LOOK TO BE SLIGHTLY HIGHER
OVERNIGHT, BUT BASES WILL STILL BE LOW AT 300-600 FT MSL WITH VIS
RESTRICTIONS 2-5 SM. DENSE FOG WITH VIS UNDER 1 SM LOOKS LESS LIKELY
THAN THIS MORNING FOR THE IMMEDIATE COAST, BUT IS STILL POSSIBLE 11-
15Z SUN.
VALLEYS/MOUNTAINS/DESERTS
VFR CONDITIONS WILL PREVAIL THROUGH
EARLY SUNDAY MORNING, BUT WITH AN INCREASE IN HIGH CLOUDS ABOVE
20000 FEET MSL FOR SATURDAY MORNING/AFTERNOON.
MARINE
ROUNDS OF OVERNIGHT/MORNING FOG REMAINS POSSIBLE THROUGH AT LEAST
TUESDAY.
LONG PERIOD WEST SWELLS OF 8-11 FEET ARE EXPECTED SUNDAY THROUGH
TUESDAY NIGHT, HIGHEST IN THE OUTER COASTAL WATERS WHERE A SMALL
CRAFT ADVISORY IS IN PLACE. 8-9 FEET WAVES POSSIBLE WITHIN 10-30 NM
OF THE COAST BUT SHOULD STILL BE FAR ENOUGH OFFSHORE TO LIMIT ANY
NEARSHORE IMPACTS. WIND GUSTS OF 20-25 KTS ARE EXPECTED TUESDAY
NIGHT IN THE OUTER COASTAL WATERS.
BEACHES
LONG PERIOD (16-19 SECOND) WEST TO NORTHWEST SWELLS (280-290
DEGREES) ARRIVE EARLY SUNDAY AND LINGERS INTO NEXT WEEK, RESULTING
IN HIGH SURF OF 6-12 FEET WITH LOCALLY HIGHER SETS CONTINUING
THROUGH WEDNESDAY. THIS WILL MAKE SWIMMING HAZARDOUS AND POSE A
COASTAL FLOODING THREAT. SEE THE HIGH SURF ADVISORY FOR MORE DETAILS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORANGE
COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
HIGH SURF ADVISORY FROM 10 PM THIS EVENING TO 4 AM PST WEDNESDAY
FOR ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL
AREAS.
PZ...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 4 AM PST
WEDNESDAY FOR WATERS FROM SAN MATEO POINT TO THE MEXICAN
BORDER EXTENDING 30 TO 60 NM OUT INCLUDING SAN CLEMENTE
ISLAND.
PUBLIC...CO
AVIATION/MARINE/BEACHES...CSP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page