436
FXUS66 KSGX 221904
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1204 PM PDT TUE SEP 22 2026
SYNOPSIS
HIGH TEMPERATURES WILL WARM SEVERAL DEGREES FOR TODAY AND
WEDNESDAY TO WITHIN A FEW DEGREES OF AVERAGE ON WEDNESDAY WITH
THE GREATEST WARMING FOR THE INLAND VALLEYS. MONSOONAL MOISTURE
FROM THE SOUTH ON THURSDAY WILL BRING A SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS DURING THE AFTERNOON. DRYING ALOFT WITH NOT
MUCH CHANGE IN TEMPERATURES FOR FRIDAY AND SATURDAY WITH A LOW
PRESSURE SYSTEM MOVING INLAND ALONG THE WEST COAST BRINGING
COOLING FOR SUNDAY AND MONDAY.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
..UPDATED AVIATION DISCUSSION
SHORT TERM (TODAY THROUGH THURSDAY)
A WEAK LOW PRESSURE SYSTEM WILL DEVELOP OFF THE COAST OF NORTHERN
BAJA TODAY AND LINGER INTO THURSDAY WITH WEAK LOWER-LEVEL EASTERLY
FLOW AND EAST WINDS FOR THE MOUNTAINS AT TIMES ON WEDNESDAY AND
THURSDAY. HIGH TEMPERATURES FOR TODAY WILL WARM A FEW DEGREES
NEAR THE COAST TO 5 TO LOCALLY 10 DEGREES FOR THE INLAND VALLEYS
ONTO THE COASTAL SLOPES OF THE MOUNTAINS. SIMILAR WARMING WILL
OCCUR AGAIN ON WEDNESDAY FROM THE COAST TO THE MOUNTAINS WITH
WARMING ALSO SPREADING INTO THE DESERTS. THERE WILL BE LITTLE
ADDITIONAL WARMING ON THURSDAY.
HIGH TEMPERATURES ON WEDNESDAY WILL BE WITHIN A FEW DEGREES ABOVE
OR BELOW AVERAGE FOR MOST AREAS WITH HIGH TEMPERATURES RANGING
FROM THE MID TO UPPER 70S NEAR THE COAST TO THE UPPER 80S TO MID
90S FOR THE INLAND EMPIRE WITH THE LOWER DESERTS AROUND 100.
ON THURSDAY, THAT WEAK LOW PRESSURE SYSTEM OFF THE NORTHERN BAJA
COAST COULD DRAW SOME MID-LEVEL MONSOONAL MOISTURE NORTHWARD INTO
SOUTHWESTERN CALIFORNIA WITH A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS FOR THE MOUNTAINS DURING THE AFTERNOON.
THE MARINE LAYER IS STILL AROUND 4500 FEET DEEP WITH LOW CLOUDS
OVER THE COASTAL WATERS EXTENDING WELL INLAND ACROSS THE COAST AND
VALLEYS AND ONTO THE LOWER COASTAL SLOPES OF THE MOUNTAINS. THE
MARINE LAYER IS EXPECTED TO DECREASE IN DEPTH FOR WEDNESDAY AND
THURSDAY WITH NIGHT AND MORNING COASTAL LOW CLOUDS NOT SPREADING
AS FAR INLAND.
LONG TERM (FRIDAY THROUGH MONDAY)
THAT WEAK LOW PRESSURE SYSTEM OFF THE NORTHERN BAJA COAST WILL
WEAKEN AND MOVE INLAND ON THURSDAY WITH DRIER WESTERLY FLOW ALOFT
FOR FRIDAY AND SATURDAY. HIGH PRESSURE ALOFT OVER NORTHERN MEXICO
AND SOUTHERN TEXAS WILL EXPAND WESTWARD ACROSS BAJA DURING THE
WEEKEND WITH HURRICANE POLO REMAINING ON A WEST-NORTHWEST TRACK
ALONG THE SOUTHERN EDGE OF THE UPPER HIGH.
NOT MUCH CHANGE IN HIGH TEMPERATURES IS EXPECTED FOR FRIDAY AND
SATURDAY WITH A LOW PRESSURE SYSTEM MOVING INLAND ACROSS THE
WESTERN STATES BRINGING COOLING FOR SUNDAY AND MONDAY.
AVIATION
221800Z...COAST/VALLEYS...NEARLY ALL LOW CLOUDS CLEARED OUT THIS
MORNING, WITH VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE
AFTERNOON. CLOUDS WITH LOWER BASES (INITIALLY AROUND 2000-2500FT
MSL) LOOK TO REDEVELOP ACROSS COASTAL SAN DIEGO COUNTY AFTER 00Z
WEDNESDAY. HIGH CONFIDENCE IN CIGS AT KSAN, LOWER CONFIDENCE AT
KCRQ BETWEEN 00-06Z. AFTER 06Z, CIGS LOOK TO SPREAD THROUGHOUT
COASTAL SD COUNTY AND NORTHWARD TOWARDS ORANGE COUNTY, WITH BASES
LIKELY LOWERING TO AROUND 1500FT MSL. MODERATE CONFIDENCE IN CIGS
AT KSNA BETWEEN 11-16Z. CLOUDS SCATTER OUT BETWEEN 16-17Z
WEDNESDAY.
OTHERWISE...MOSTLY CLEAR SKIES TODAY AND TONIGHT.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH SUNDAY.
SGX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...NONE.
PUBLIC...CO
AVIATION/MARINE...MUNYAN
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