815
FXUS66 KSGX 051107
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
407 AM PDT SAT JUL 5 2025
SYNOPSIS
HIGH TEMPERATURES NEAR AVERAGE WITH NIGHT AND MORNING LOW CLOUDS
CLOSER TO THE COAST CAN BE EXPECTED THROUGH MONDAY. HIGH PRESSURE
OVER THE DESERT SOUTHWEST WILL BUILD INTO THE REGION FOR TUESDAY
INTO LATER NEXT WEEK, BRINGING HOTTER WEATHER FOR INLAND AREAS.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
TODAY THROUGH MONDAY...
THE UPPER LEVEL TROUGH THAT IS CURRENTLY OVER THE EASTERN PACIFIC
OCEAN WILL CONTINUE TO DEEPEN WITH AN UPPER LEVEL LOW BECOMING
CLOSED AT THE 500 MB LEVEL BY LATER IN THE DAY. SUBSEQUENTLY, THE
SUBTROPICAL RIDGE OVER THE DESERT SOUTHWEST WILL BEGIN TO FURTHER
AMPLIFY WITH THE RIDGE AXIS EVER SO SLOWLY RETROGRADING WESTWARD
AND BACK TOWARDS THE REGION. THIS WILL ALLOW FOR TEMPERATURES TO
STEADILY CONTINUE TO RISE EACH DAY, WITH A MUCH TIGHTER CONTRAST
IN TEMPERATURES FROM THE COAST TO THE DESERTS. THIS, ALONG WITH
THE TIGHTENED PRESSURE GRADIENT FROM THE LOW AND THE SEA BREEZE
BEING ENHANCED DURING THE DAY BY THE THERMAL LOW ESTABLISHING
ITSELF OVER THE LOWER DESERTS, IS GOING TO ALLOW FOR WINDS TO
INCREASE OUT OF THE WEST AND BECOME RATHER GUSTY EACH AFTERNOON,
ESPECIALLY THROUGH THE SAN GORGONIO PASS. THE MARINE LAYER IS
GOING TO BE RATHER PERSISTENT OVERNIGHT AND MAKE IT INTO A
MAJORITY OF THE INLAND VALLEYS OF ORANGE AND SAN DIEGO COUNTIES,
AND A PORTION OF THE INLAND EMPIRE.
TUESDAY THROUGH FRIDAY...
THE UPPER LEVEL LOW IS GOING TO OPEN BACK UP AND BECOME ABSORBED
BACK INTO THE LONGWAVE TROUGH UPSTREAM, MEANWHILE THE SUBTROPICAL
RIDGE IS GOING TO CONTINUE TO BUILD WITH AN AREA OF HIGH PRESSURE
SETTING UP OVER ARIZONA. THIS WILL ALLOW FOR TEMPERATURES TO BECOME
VERY HOT FOR THE DESERTS AND INLAND VALLEYS, WITH HEAT PRODUCTS
BEING POSSIBLE FROM TUESDAY THROUGH THURSDAY UNDER THE MOST INTENSE
HIGH PRESSURE...ALTHOUGH THERE IS A CAVEAT TO THIS, AND THAT IS THE
INCREASED AMOUNT OF MOISTURE FOR THE DESERTS, WHICH MAY HELP TO KEEP
TEMPERATURES JUST COOL ENOUGH TO WHERE THE HEATRISK INDICES DO
NOT EXCEED CRITERIA. THERE COULD ALSO BE HEAT PRODUCTS NEEDED FOR
THE IE, AS TEMPERATURES WILL LIKELY TOP OUT OVER 100F FOR MOST
LOCATIONS TUESDAY THROUGH THURSDAY, WITH WEDNESDAY LIKELY BEING
THE HOTTEST DAY OF THE WEEK. THERE COULD BE A FEW LOCATIONS WITHIN
THE COACHELLA VALLEY APPROACHING THE 120F MARK. THE MARINE LAYER
IS GOING TO CONTINUE TO THIN AND LOWER THROUGHOUT THIS PERIOD IN
THE FORECAST, AND THERE COULD ALSO BE SOME PATCHY FOG FOR SOME OF
THE COASTAL AREAS AND OUT OVER THE OPEN WATERS DURING THE
OVERNIGHT HOURS.
BY FRIDAY, THE RIDGE WILL BEGIN TO WEAKEN AND TEMPERATURES WILL DROP
OFF CLOSER TO THE SEASONAL AVERAGE FOR THIS TIME OF YEAR AS THE
REGION BECOMES MORE INFLUENCED BY THE TROUGH OVER THE PACIFIC OCEAN.
AVIATION
051000Z....COAST/VALLEYS...LOW CLOUDS BASED 900-1400 FEET MSL HAVE
PUSHED INTO SD/ORANGE COUNTIES ABOUT 10-15 MILES INLAND. VIS
RESTRICTIONS (3-5SM) FOR ELEVATED VALLEYS (I.E. KL18). CLOUDS MAY
PUSH A LITTLE FURTHER INLAND THROUGH 12Z, BUT LIKELY STAYING OUT OF
THE IE. CLEARING OF LOW CLOUDS BACK TO THE COAST WILL OCCUR QUICKLY
SATURDAY MORNING, BY 16-17Z. VFR PREVAILS SATURDAY AFTERNOON AND
EVENING, BEFORE PATCHIER LOW CLOUDS BASED 700-1200 FT MSL REDEVELOP
AND MOVE ASHORE LATE IN THE EVENING, LIKELY AFTER 06Z SUN. SLIGHTLY
LESS INLAND EXTENT THAN THIS MORNING. VIS RESTRICTIONS FOR ELEVATED
COASTAL TERRAIN AND WESTERN VALLEYS.
VIS RESTRICTIONS (2-6SM) REMAIN POSSIBLE IN FU ASSOCIATED WITH
FIREWORKS THROUGH THIS MORNING MORNING, ESPECIALLY IN ORANGE COUNTY
AND WESTERN IE.
MOUNTAINS/DESERTS...SUNNY WITH MOSTLY UNRESTRICTED VIS THROUGH
SATURDAY NIGHT.
MARINE
NO HAZARDOUS MARINE WEATHER CONDITIONS ARE EXPECTED THROUGH
WEDNESDAY.
BEACHES
SOUTHERLY SWELL (190 DEGREES) OF 3 TO 4 FEET AT 15-17 SECONDS WILL
GENERATE ELEVATED SURF OF 4-6 FT WITH SETS TO 7 FT ALONG SOUTH
FACING BEACHES THROUGH SUNDAY. IN ADDITION, STRONG RIP AND LONGSHORE
CURRENTS ARE EXPECTED AT ALL BEACHES THROUGH SUNDAY. A BEACH HAZARDS
STATEMENT IS IN EFFECT AND CONTAINS MORE INFORMATION. SURF MAY
REMAIN ELEVATED INTO EARLY NEXT WEEK.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...BEACH HAZARDS STATEMENT THROUGH SUNDAY EVENING FOR ORANGE COUNTY
COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
PZ...NONE.
PUBLIC...STEWEY
AVIATION/MARINE/BEACHES...KW
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