043
FXUS66 KMTR 130822
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
122 AM PDT SAT SEP 13 2025
..NEW SHORT TERM, LONG TERM
KEY MESSAGES
UPDATED AT 120 AM PDT SAT SEP 13 2025
- TEMPERATURES AROUND OR SLIGHTLY BELOW NORMAL TODAY AND SUNDAY
- MUCH WARMER TEMPERATURES FOR THE FIRST HALF OF THE UPCOMING
WORK WEEK
- MODERATE HEATRISK POSSIBLE INLAND MONDAY THROUGH WEDNESDAY
SHORT TERM
ISSUED AT 120 AM PDT SAT SEP 13 2025
(TODAY AND TONIGHT)
COVERAGE OF LOW STRATUS IS INCREASING OVERNIGHT. THE MARINE LAYER
HAS BUILT UP TO AROUND 2000FT ALLOWING FOR A FARTHER INTRUSION
INLAND. LOW CLOUD DECK SHOULD ERODE INLAND BY LATE MORNING, LIKELY
BY EARLY AFTERNOON CLOSER TO THE COAST. PORTIONS OF THE IMMEDIATE
COAST FROM THE BAY AREA DOWN TO MONTEREY BAY MAY HAVE LOW CLOUDS
LINGER THROUGHOUT THE ENTIRE DAY, EVEN AS THE MARINE LAYER
RETREATS BACK TO THE COASTLINE. DESPITE THE PASSAGE OF A
PROGRESSIVE, AMPLIFIED RIDGE ACROSS THE WEST COAST TODAY, HIGHS
WILL REMAIN NEAR OR SLIGHTLY BELOW NORMAL. OVERNIGHTS LOWS INTO
SUNDAY MORNING WILL GENERALLY BE IN THE MID 50S TO LOW 60S.
LONG TERM
ISSUED AT 120 AM PDT SAT SEP 13 2025
(SUNDAY THROUGH FRIDAY)
AN UPPER TROUGH IN THE WAKE OF THE PROGRESSIVE RIDGING TODAY WILL
PUSH A WEAK COLD FRONT THROUGH OUR AREA SUNDAY, WITH LITTLE TO NO
EFFECT ON TEMPERATURES. THE PRIMARY CONCERN FOR THE EXTENDED
FORECAST WILL BE HEATRISK FOR THE FIRST HALF OF THE UPCOMING WORK
WEEK. A BROAD UPPER LEVEL RIDGE BEGINS TO DEVELOP OVER THE EASTERN
PACIFIC ON MONDAY. A PERIOD OF WEAK OFFSHORE FLOW MONDAY MORNING
THROUGH TUESDAY MORNING WILL LIFT TEMPERATURES ABOVE NORMAL, WITH
BIGGEST IMPACTS BEING FELT CLOSER TO THE COAST AS THE MARINE LAYER
ERODES. THE EAST BAY HILLS, PORTIONS OF THE SOUTH BAY AND
SOUTHERN MONTEREY COUNTY MAY SEE HIGHS IN THE UPPER 90S
APPROACHING 100 MONDAY THROUGH WEDNESDAY. SOME UNCERTAINTY REMAINS
IN THE UPPER LEVEL PATTERN. THE ECMWF HAS AN UPPER LEVEL LOW
UNDERCUTTING THE BASE OF THE RIDGE CLOSER TO OUR LATITUDE WITH THE
GFS MUCH FARTHER SOUTH LATE TUESDAY INTO WEDNESDAY. WILL WAIT TO
START MESSAGING MORE IMPACTFUL HEAT UNTIL BETTER CONSENSUS IS
REACHED IN GUIDANCE. NBM SEEMS REASONABLE AT THIS POINT, BUT DID
STILL BUMP TEMPERATURES UP MON-WED. CONFIDENCE IN THE PATTERN AND
RESULTING WEATHER IS EVEN LOWER INTO LATE NEXT WEEK AND WEEKEND.
AVIATION
(06Z TAFS)
ISSUED AT 930 PM PDT FRI SEP 12 2025
LOW CLOUDS ARE AFFECTING HAF AND AND THE BAYS AS WINDS WEAKEN.
STATUS BUILDS AND MOVES INLAND INTO THE NIGHT BECOMING WIDESPREAD
INTO SATURDAY MORNING. POCKETS OF FOG LOOK TO AFFECT STS IN THE
EARLY TO MID MORNING. CLOUD COVER WILL BE SLOW TO ERODE ON SATURDAY,
BUT NEARLY WIDESPREAD VFR IS EXPECTED INT THE AFTERNOON. THE
EXCEPTION BEING HAF, WHICH SEES CIGS RISE TO MVFR LEVELS, BUT DON'T
CLEAR. SATURDAY AFTERNOON OFFERS ANOTHER ROUND OF MODERATE TO BREEZY
WINDS ARRIVE AND LAST INTO THAT EVENING. CLOUD COVER BUILDS AROUND
THE MONTEREY BAY IN THE LATE AFTERNOON AND AROUND THE SF BAY THAT
EVENING.
VICINITY OF SFO...WINDS ARE REDUCING AND MVRF CIGS STAY IN PLACE
THROUGH THE NIGHT AND SATURDAY MORNING. THESE CIGS ERODE AS BREEZY
WEST WINDS BUILD SATURDAY AFTERNOON, BUT MVFR CIGS RETURN AS THE
WINDS REDUCE INTO SATURDAY NIGHT.
SFO BRIDGE APPROACH...SIMILAR TO SFO.
MONTEREY BAY TERMINALS...MVFR/IFR CIGS HAVE FILLED AROUND THE BAY AS
WINDS REDUCED AND BECAME LIGHT. CIGS AT MRY AND SNS LOOK TO FALL TO
IFR LEVELS INTO THE LATE NIGHT WITH WINDS BECOMING LIGHT AND
VARIABLE. CIGS LIFT TO MVFR LEVELS IN THE MID MORNING THEN ERODE
INTO SATURDAY AFTERNOON AS MODERATE WEST WINDS BUILD. IFR CIGS LOOK
TO RETURN TO THE MONTEREY BAY IN THE LATE AFTERNOON AND EARLY EVENING
AS WINDS REDUCE.
MARINE
(TONIGHT THROUGH NEXT THURSDAY)
ISSUED AT 930 PM PDT FRI SEP 12 2025
WINDS REDUCE INTO THE LATE NIGHT ACROSS THE WATERS, LEADING TO
CALMER CONDITIONS INTO SATURDAY MORNING. FRESH TO STRONG GUSTS
WILL BE POSSIBLE IN THE FAVORED COASTAL JET REGIONS AND ACROSS THE
OFFSHORE ZONES THROUGH THIS WEEKEND CREATING HAZARDOUS CONDITIONS
FOR SMALL CRAFT. MODERATE SEAS PERSIST, ESPECIALLY OFFSHORE.
ANOTHER ROUND OF WIDESPREAD FRESH TO STRONG NORTHWESTERLY BREEZES
BEGINS SUNDAY INTO NEXT WEEK WITH THE STRONGEST WINDS LOCATED
ACROSS THE FAR NORTHERN OUTER WATERS.
MTR WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 9 PM PDT THIS
EVENING FOR MRY BAY-PIGEON PT TO PT PINOS 0-10 NM-PT ARENA
TO PT REYES 10-60 NM.
SMALL CRAFT ADVISORY UNTIL 3 AM PDT EARLY THIS MORNING FOR PT
ARENA TO PT REYES 0-10 NM-PT ARENA TO PT REYES 10-60 NM-PT
PINOS TO PT PIEDRAS BLANCAS 0-10 NM.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM PDT SUNDAY
FOR PT ARENA TO PT REYES 0-10 NM-PT PINOS TO PT PIEDRAS
BLANCAS 0-10 NM.
SHORT TERM...JM
LONG TERM....JM
AVIATION...MURDOCK
MARINE...MURDOCK
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