373  
FXUS66 KMTR 051843  
AFDMTR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN FRANCISCO CA  
1143 AM PDT FRI SEP 5 2025  
   
..NEW AVIATION  
 
   
KEY MESSAGES  
 
UPDATED AT 1214 AM PDT FRI SEP 5 2025  
 
- A GRADUAL COOLING TREND CONTINUES INTO NEXT WEEK.  
 
- CHANCE FOR LIGHT RAIN EARLY NEXT WEEK.  
 
 
   
UPDATE  
 
ISSUED AT 922 AM PDT FRI SEP 5 2025  
 
STRATUS IS STARTING TO RECEDE ACROSS THE INTERIOR WITH CLOUD COVER  
LIKELY TO DISSIPATE BY LATE MORNING INTO THE EARLY AFTERNOON. SOME  
COASTAL DRIZZLE WAS OBSERVED THIS MORNING WITH SEVERAL SITES ACROSS  
THE BAY AREA REPORTING ONE TO TWO HUNDREDTHS OF DRIZZLE THIS  
MORNING. OTHERWISE, THE FORECAST REMAINS ON TRACK WITH HIGH  
TEMPERATURES IN THE 70S TO MID 80S ACROSS THE INTERIOR AND 60S ALONG  
THE COASTLINE.  
 
 
   
SHORT TERM  
 
ISSUED AT 1214 AM PDT FRI SEP 5 2025  
(TODAY AND TONIGHT)  
 
A DEEP MARINE LAYER IS BRINGING EXTENSIVE STRATUS COVERAGE ACROSS  
THE CWA. SOME MEASURABLE DRIZZLE HAS BEEN REPORTED ALONG THE  
NORTH BAY COAST, WITH MORE TO COME THROUGH THE MORNING. THE  
OVERALL PATTERN IS DOMINATED BY A SLOW MOVING TROUGH OFF THE COAST  
THAT WILL BRING A COOLING TREND WITH CONTINUED MARINE LAYER  
CLOUDS AND COASTAL DRIZZLE SATURDAY MORNING.  
 
 
   
LONG TERM  
 
ISSUED AT 1214 AM PDT FRI SEP 5 2025  
(SATURDAY THROUGH THURSDAY)  
 
THE PATTERN IS DOMINATED BY A BUILDING TROUGH OFF THE COAST  
THROUGH THE MIDDLE OF NEXT WEEK. THERE IS A COMPETING RIDGE OVER  
NORTHERN MEXICO THAT WILL LIKELY MAKE SOME IMPACT THIS WEEKEND  
BEFORE TROUGHING TAKES BACK OVER. AS THIS TROUGH SLOWLY DEEPENS  
AND PUSHES CLOSER TO THE COAST, 850 TEMPS WILL FALL FROM 21C  
(75TH PERCENTILE) MEASURED ON THE LATEST BALLOON, TO AROUND 12C  
(10TH PERCENTILE) BY TUESDAY. MOISTURE WILL ALSO BE HIGHER THAN  
NORMAL WITH A NOTABLE PUSH OF PW OVER 1" ON MONDAY FOLLOWED BY AN  
EARLY SEASON COLD FRONT AND UPPER LEVEL TROUGH AXIS ON TUESDAY.  
THIS COMBINATION WILL BRING A GOOD CHANCE FOR LIGHT RAIN,  
ESPECIALLY TO THE NORTH BAY, STARTING MONDAY. THERE IS ALSO A  
SLIGHT CHANCE FOR STRONGER CONVECTION OR EVEN THUNDERSTORMS WHEN  
THE COLD UPPER AIR MOVES IN ON TUESDAY. MODEL SUPPORT IS MEAGER AT  
THE MOMENT, BUT THE INGREDIENTS ARE THERE AND IT'S WORTH KEEPING  
AN EYE ON. THE CHANCE FOR PRECIPITATION IS INCREASING, BUT EXACT  
AMOUNTS REMAIN UNCERTAIN. MOST LIKELY WE'LL SEE A FEW LOCATIONS  
NORTH OF GOLDEN GATE RECORD 1/10" OR MORE, WITH MORE NOVELTY RAIN  
FURTHER SOUTH. THERE IS MORE CONFIDENCE IS THE TEMPERATURE  
FORECAST, WITH HIGHS DROPPING 5-10 DEGREES BELOW NORMAL BY EARLY  
NEXT WEEK.  
 
 
   
AVIATION  
 
(18Z TAFS)  
ISSUED AT 1143 AM PDT FRI SEP 5 2025  
 
INLAND CIGS ARE ERODING, LEADING TO WIDESPREAD VFR INTO THE MID  
AFTERNOON FOR ALL BUT THE IMMEDIATE COAST AND HAF WHICH LOOKS TO  
KEEP MVFR CIGS. WINDS INCREASE INTO THE AFTERNOON, BECOMING MODERATE  
TO BREEZY. THESE WINDS REDUCE INTO THE EVENING AS CIGS BEGIN TO MOVE  
INLAND AND LOWER TO IFR LEVELS AT HAF. EXPECT IFR/MVFR CIGS TO BUILD  
AROUND THE BAYS IN THE EVENING AND SPREAD FARTHER INLAND FURTHER  
INTO THE NIGHT WITH WIDESPREAD CIGS AND LIGHT WINDS EXPECTED INTO  
THE LATE NIGHT. EXPECT SIMILAR CLEARING TO SLIGHTLY EARLIER CLEARING  
TIMES FOR SATURDAY.  
 
VICINITY OF SFO...CLOUD COVER ERODES INTO THE MID AFTERNOON AS  
BREEZY WINDS BUILD AND GUSTS BEGIN TO PEAK AROUND 23 KTS. CLOUD  
COVER RETURNS IN THE MID EVENING AND FILLS AT SFO AS WINDS REDUCE  
AND BECOME MODERATE. MVFR CIGS STAY IN PLACE THROUGH ALL OF SATURDAY  
MORNING, BUT VFR RETURNS AROUND NOON AS BREEZY WEST WINDS BUILD AND  
CLOUD COVER EXITS.  
 
SFO BRIDGE APPROACH...SIMILAR TO SFO.  
 
MONTEREY BAY TERMINALS...VFR LASTS THROUGH THE EARLY EVENING. WINDS  
ARE INCREASING, BECOMING MODERATE TO BREEZY. EXPECT WINDS TO REDUCE  
IN THE EARLY EVENING AS IFR/MVFR CIGS FILL OVER THE TERMINALS AND  
MOVE INLAND. THESE CIGS ERODE IN THE LATE MORNING AND  
EARLY AFTERNOON FOR SATURDAY AS MODERATE WINDS BUILD.  
 
 
   
MARINE  
 
(TODAY THROUGH WEDNESDAY)  
ISSUED AT 922 AM PDT FRI SEP 5 2025  
 
MODERATE NORTHWESTERLY WINDS CONTINUE INTO THE WEEKEND WITH  
LOCALLY STRONG GUSTS ALONG THE COASTAL JET ALONG BIG SUR.  
NORTHWESTERLY BREEZES WILL BE GENTLE TO MODERATE THIS WEEKEND AND  
INTO EARLY NEXT WEEK. MODERATE SEAS WILL PREVAIL THROUGH TUESDAY.  
 
 
   
MTR WATCHES/WARNINGS/ADVISORIES  
 
CA...NONE.  
PZ...SMALL CRAFT ADVISORY UNTIL 3 AM PDT SATURDAY FOR PT PINOS TO PT  
PIEDRAS BLANCAS 0-10 NM.  
 
 
 
 
 
SHORT TERM...FLYNN  
LONG TERM....FLYNN  
AVIATION...MURDOCK  
MARINE...MURDOCK  
 
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