938
FXUS66 KSGX 301847
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1147 AM PDT SUN AUG 30 2026
SYNOPSIS
GRADUAL COOLING TREND THROUGH THE MIDDLE OF THE UPCOMING WEEK. FOR
TUESDAY AND WEDNESDAY, INCREASED HIGH CLOUD COVER CONTINUES TO LOOK
LIKELY, BUT PRECIPITATION CHANCES HAVE DECREASED. GRADUAL WARMING
FOR THE LATTER HALF OF NEXT WEEK, WITH TEMPERATURES REMAINING NEAR
OR SLIGHTLY ABOVE AVERAGE. NIGHT AND MORNING COASTAL LOW CLOUDS
EXPECTED MOST MORNINGS THIS WEEK, REACHING INTO THE WESTERN VALLEYS
AT TIMES. WE'RE MONITORING THE POTENTIAL FOR WIDESPREAD
PRECIPITATION OVER LABOR DAY WEEKEND, HOWEVER THERE IS HIGH
UNCERTAINTY IN HOW THE FORECAST WILL EVOLVE.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
AT 11 AM, TEMPERATURES WERE RUNNING 2 TO 8 DEGREES COOLER THAN
THEY WERE AT THAT TIME YESTERDAY ACROSS THE AREA. A GRADUAL
COOLING IS EXPECTED EACH DAY THROUGH TUESDAY, WITH MINOR WARMING
EXPECTED FOR THE LATTER HALF OF THE WEEK. EVEN WITH THE WARMING,
TEMPERATURES ARE EXPECTED TO STAY NEAR TO SLIGHTLY ABOVE AVERAGE
FOR THIS TIME OF YEAR.
BROAD TROUGHING IS EXPECTED PREVAIL OVER THE WESTERN UNITED STATES
THROUGH AT LEAST THE MIDDLE OF THE WEEK, WHICH WILL KEEP THE FLOW
ALOFT SOUTHWESTERLY AND CUT DOWN THE HUMIDITY. IN ADDITION, WINDS
WILL INCREASE EACH AFTERNOON WITH THE SEA BREEZE, MOST NOTICEABLE
FOR MOUNTAINS, PASSES, AND CANYONS. LATEST FORECAST HAS BACKED OFF
ON PRECIPITATION FROM TROPICAL CYCLONE KARINA, WITH CURRENT CHANCES
NOW LESS THAN 15 PERCENT. THE MOST LIKELY SCENARIO IS THERE WILL BE
MORE WIDESPREAD HIGH CLOUD COVERAGE TUESDAY INTO WEDNESDAY. THE
MARINE LAYER IS EXPECTED TO CONTINUE TO REBUILD OVER THE NEXT FEW
DAYS, WITH THE POTENTIAL FOR NIGHT AND MORNING LOW CLOUDS TO REACH
INTO THE WESTERN VALLEYS. DEPENDING ON THE EXTENT OF HIGH CLOUD
COVERAGE MID-WEEK, LOW CLOUD COVERAGE MAY BE DISRUPTED AGAIN.
LATE IN THE WEEK, ENSEMBLES BEGIN TO DIVERGE ON THE PLACEMENT OF THE
UPPER TROUGH NEAR THE WEST COAST AND THE UPPER HIGH OVER THE
SOUTHERN ROCKIES, WITH A TREND TOWARDS A MORE EASTWARD PLACEMENT OF
EACH. THIS MORE EASTWARD PLACEMENT OF THE RIDGE AND TROUGHING CLOSER
TO THE COAST WOULD LIMIT THE AMOUNT OF WARMING LATE IN THE WEEK INTO
NEXT WEEKEND. THIS WOULD ALSO AFFECT THE STEERING FLOW OF A
POTENTIAL TROPICAL SYSTEM AND ANY MOISTURE AND PRECIPITATION WE'D
RECEIVE FROM IT OVER THE WEEKEND INTO EARLY NEXT WEEK. WHILE THE
NATIONAL HURRICANE CENTER HAS A 90% CHANCE OF THIS DISTURBANCE
DEVELOPING INTO A TROPICAL CYCLONE OFF THE COAST OF MEXICO IN THE
NEXT 7 DAYS, IT IS FAR TOO EARLY TO TELL WHAT, IF ANY, IMPACTS WE'LL
SEE LOCALLY, ESPECIALLY GIVEN THE ENSEMBLE SPREAD IN THE UPPER LEVEL
PATTERN. CURRENT FORECAST HAS AT LEAST A CHANCE OF PRECIPITATION
NEXT WEEKEND.
AVIATION
301800Z...COASTS/VALLEYS...CLOUDS HAVE FULLY CLEARED OUT THIS
MORNING, WITH VFR CONDITIONS PREVAILING THROUGH THE AFTERNOON.
CLOUDS BASED 1000-1500FT MSL REDEVELOP AFTER 02Z MONDAY, WITH FULL
CIGS EXPECTED ACROSS COASTAL SAN DIEGO COUNTY BY 05-06Z. OVERNIGHT,
LOW CLOUDS EXPECTED TO FILL INLAND THROUGH ABOUT 15 MILES, WITH
PATCHY CIGS SPREADING INTO ORANGE COUNTY AFTER 09Z. THERE IS ABOUT A
60% CHANCE OF CIGS IMPACTING KSNA BETWEEN 11-16Z MONDAY. VIS
RESTRICTIONS LIMITED TO WHERE CLOUDS INTERSECT HIGHER TERRAIN.
CLOUDS SCATTER OUT BY 16-17Z.
MTNS/DESERTS
OCCASIONAL FEW HIGH LVL CLOUDS AOA 20,000FT MSL
THROUGH THE PERIOD. BREEZY WEST TO SOUTHWEST WINDS 20Z THIS
AFTERNOON TO ABOUT 05Z MONDAY FOR THE DESERT SLOPES INTO THE
DESERTS, WITH GUSTS TO 20-30 KTS, LOCALLY UP TO 35-40 KTS THROUGH
PASSES.
MARINE
GUSTS AROUND 20 KNOTS EXPECTED EACH AFTERNOON THROUGH THURSDAY IN
THE VICINITY OF SAN CLEMENTE ISLAND. LOCALIZED GUSTS NEAR THE ISLAND
MAY REACH 25 KTS ON TUESDAY/WEDNESDAY AFTERNOONS. OTHERWISE, NO
HAZARDOUS MARINE CONDITIONS ARE EXPECTED.
BEACHES
A 3-FOOT SWELL FROM THE SOUTH-SOUTHWEST (200 DEGREES) AT 15 SECONDS
WILL PERSIST THROUGH TODAY. THIS WILL BRING LOCALIZED ELEVATED SURF
OF 3-5 FEET WITH SETS TO 6 FEET, ALONG WITH A HIGH RIP CURRENT RISK
TO SOUTHWEST-FACING BEACHES, MOSTLY IN NORTH SAN DIEGO COUNTY AND
ORANGE COUNTY. A NEW SOUTHERLY SWELL (180-190 DEGREES) FROM
HURRICANE KARINA WILL KEEP SURF ELEVATED AT 3-5 FEET WITH SETS TO 6
FEET FOR MONDAY THROUGH WEDNESDAY. CONTINUED TROPICAL SWELLS LOOK TO
KEEP SURF ELEVATED THROUGH THE END OF THE WEEK AS WELL.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...NONE.
PUBLIC...CO
AVIATION/MARINE/BEACHES...MUNYAN
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