598
FXUS66 KMTR 311030
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
330 AM PDT FRI OCT 31 2025
..NEW SHORT TERM, LONG TERM
KEY MESSAGES
UPDATED AT 212 AM PDT FRI OCT 31 2025
- NICE AND QUIET WITH WARM TEMPS THROUGH THIS WEEKEND.
- COOLER TEMPS (NEAR AVERAGE) BY THE START OF NEXT WEEK.
- CONFIDENCE INCREASING ON THE NEXT RAIN MAKER, SET TO ARRIVE BY
THE MIDDLE OF NEXT WEEK.
SHORT TERM
ISSUED AT 212 AM PDT FRI OCT 31 2025
(TODAY AND TONIGHT)
PLEASANT AND QUIET CONDITIONS ON TAP TODAY AS LONGWAVE RIDGING
DOMINATES THE PATTERN OVER THE WESTERN US. MORE OF A SUMMER-TIME
PATTERN FOR US WITH FOG AND STRATUS MIXING OUT AFTER SUNRISE AND
RETURNING TONIGHT WITH A WELL-FORMED MARINE LAYER REMAINING INTACT
THROUGH THE DAY. HIGHS TODAY ABOUT 5-10 DEGREES ABOVE NORMAL.
LONG TERM
ISSUED AT 212 AM PDT FRI OCT 31 2025
(SATURDAY THROUGH THURSDAY)
BEYOND THE WEEKEND IS WHEN WE START TO FIND THE NEXT THING WORTH
TALKING ABOUT. MEDIUM-RANGE GUIDANCE HAS BEEN ADVERTISING A
NOTABLE PATTERN CHANGE WITH A DEEP UPPER LOW IN THE GULF OF ALASKA
HELPING TO ERODE THE DOWNSTREAM RIDGE. THIS OPENS THE DOOR FOR A
ROBUST 150 KT PACIFIC JET ACROSS THE ALEUTIANS TO PROMOTE ANOTHER
DEEP UPPER LOW DIGGING INTO THE EPAC OFF THE WEST COAST. THIS WILL
BE OUR STORM TO WATCH. CONFIDENCE IS INCREASING FOR IMPACTFUL
RAINFALL IN THE NORTH BAY ON WEDNESDAY. ENSEMBLE CLUSTER ANALYSIS
SHOWS THAT APPROX 74% OF MEMBERS ADVERTISE RAINFALL AMOUNTS
GREATER THAN THE ENSEMBLE MEAN. ESSENTIALLY WHAT THIS MEANS IS
THAT THERE IS BETTER AGREEMENT ON THE HIGHER END OF THE MODEL
SPREAD. WHAT IS THIS SPREAD? GREAT QUESTION. THE 25TH-75TH
PERCENTILES FOR THE NORTH BAY ARE RUNNING ABOUT 0.75"-1.75" ON
AVERAGE (24 HOUR TOTALS, AND GIVE OR TAKE A HALF INCH DEPENDING ON
WHERE YOU ARE IN THE COUNTY). SURE, NOT OUTSTANDING FOR THE NORTH
BAY, BUT AT LEAST THIS TELLS US THAT WE MAY BE IN FOR A DECENT
RAINFALL. POTENTIALLY THE MOST WE'VE SEEN THIS SEASON IN THOSE
PARTS. THINGS ARE MORE UNCERTAIN FOR THE REST OF THE BAY AREA AND
CENTRAL COAST. THERE IS NOT ENOUGH CERTAINTY HERE TO GIVE A
MEANINGFUL FORECAST AT THIS POINT, BUT AT THE VERY LEAST EXPECT
SOME RAIN AND WIND. MORE ON THE WIND...AS THE TROUGH SWINGS
THROUGH ON WEDNESDAY, WE'LL LIKELY SEE WIDESPREAD IMPACTFUL WINDS
ASSOCIATED WITH THE PASSAGE OF THE UPPER LEVEL JET CORE. CURRENT
MODEL GUIDANCE HINTS AT A DECENT CHANCE OF SEEING 50 KTS AT 850
MB, WHICH WOULD BE NEAR THE DAILY RECORD MAX FOR THIS TIME OF
YEAR. AGAIN, NOTHING COMPARED TO STRONGER STORMS THAT WE MAY SEE
IN DECEMBER-FEBRUARY, BUT FAIRLY RESPECTABLE FOR THIS POINT IN THE
SEASON.
AVIATION
(06Z TAFS)
ISSUED AT 1106 PM PDT THU OCT 30 2025
CURRENTLY A MIXED BAG OF IFR-VFR AT THE TERMINALS. PESSIMISTIC
PERSISTENCE FORECAST ON TAP WITH IFR-MVFR CONDITIONS EXPECTED AT ALL
TERMINALS TONIGHT.
VICINITY OF SFO...CURRENTLY MVFR WITH GUSTY WESTERLY FLOW. A CEILING
ON THE CUSP OF IFR/MVFR WILL PREVAIL THROUGH THE MORNING WITH
SIMILAR CONDITIONS ON TAP FOR TOMORROW NIGHT.
SFO BRIDGE APPROACH...SIMILAR TO SFO.
MONTEREY BAY TERMINALS...CURRENTLY IFR WITH SOUTHWESTERLY FLOW AT
MRY AND IFR WITH WESTERLY FLOW AT SNS. IFR WILL PREVAIL THROUGH THE
TAF PERIOD FOR MRY WITH AT LEAST BRIEF VFR FOR SNS.
MARINE
(TONIGHT THROUGH NEXT WEDNESDAY)
ISSUED AT 1106 PM PDT THU OCT 30 2025
BUILDING HIGH PRESSURE TO THE NORTH WILL KEEP MODERATE TO FRESH
WINDS OVER THE WATERS WITH LOCALLY STRONGER OCCASIONAL GALE FORCE
GUSTS OVER THE OUTER WATERS AND NEARSHORE SOUTH OF POINT SUR
THROUGH THE WEEKEND. SEAS WILL SUBSIDE ON FRIDAY THEN REBUILD OVER
THE WEEKEND WITH A LONGER PERIOD SWELL. WINDS REDUCE INTO THE
EARLY WORK WEEK, BUT BUILD AGAIN IN NEXT WEEK WITH UNSETTLED
WEATHER RETURNING.
MTR WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 3 AM PDT EARLY THIS MORNING FOR MRY
BAY-PIGEON PT TO PT PINOS 0-10 NM-PT ARENA TO PT REYES 0-10
NM-PT REYES TO PIGEON PT 0-10 NM.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM PDT
SATURDAY FOR PIGEON PT TO PT PINOS 0-10 NM-PT ARENA TO PT
REYES 0-10 NM.
SMALL CRAFT ADVISORY UNTIL 9 PM PDT THIS EVENING FOR PT PINOS TO
PT PIEDRAS BLANCAS 0-10 NM.
SMALL CRAFT ADVISORY UNTIL 9 AM PDT SATURDAY FOR PT ARENA TO PT
REYES 10-60 NM.
SMALL CRAFT ADVISORY UNTIL 3 AM PDT SATURDAY FOR PIGEON PT TO PT
PINOS 10-60 NM.
SHORT TERM...BEHRINGER
LONG TERM....BEHRINGER
AVIATION...SARMENT
MARINE...MM
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