672
FXUS66 KMTR 221938
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1238 PM PDT TUE SEP 22 2026
..NEW SHORT TERM, LONG TERM
KEY MESSAGES
UPDATED AT 1232 PM PDT TUE SEP 22 2026
- WARMING TREND CONTINUES THROUGH THURSDAY
- COOLER CONDITIONS FRIDAY INTO THE WEEKEND
SHORT TERM
ISSUED AT 1232 PM PDT TUE SEP 22 2026
(THIS EVENING THROUGH WEDNESDAY NIGHT)
AN UPPER LEVEL TROUGH IS MOVING ACROSS NEVADA THIS AFTERNOON AND
WILL CONTINUE TO SHIFT INTO THE GREAT BASIN ON WEDNESDAY. AS SUCH,
TEMPERATURES THIS AFTERNOON ARE FORECAST TO WARM INTO THE 60S NEAR
THE COAST, UPPER 60S TO LOW 70S AROUND THE BAYSHORE, AND MID 70S TO
MID 80S ACROSS THE INTERIOR WITH MOSTLY SUNNY SKY CONDITIONS ACROSS
THE INTERIOR. BREEZY ONSHORE FLOW WILL DEVELOP IN THE AFTERNOON AND
EVENING HOURS WITH GUSTS OF 20 TO 30 MPH NEAR THE COAST, IN THE
FAVORED GAPS AND PASSES, AND DOWN THE SALINAS VALLEY.
AS THE MARINE LAYER GRADUALLY COMPRESSES TO AROUND 1,500 FEET
TONIGHT, WE ARE EXPECTING LESS OF AN INLAND INTRUSION OF STRATUS. AS
SUCH, TEMPERATURES ARE EXPECTED TO COOL INTO THE 50S FOR MUCH OF THE
REGION OVERNIGHT. MORE OF A ZONAL FLOW IS FORECAST ON WEDNESDAY
WHICH WILL LEAD TO A WARMING TREND. TEMPERATURES WEDNESDAY AFTERNOON
ARE FORECAST TO REACH INTO THE UPPER 60S TO MID 70S NEAR THE COAST,
UPPER 70S TO MID 80S AROUND THE BAYSHORE, AND MID 80S TO LOW 90S
ACROSS THE INTERIOR. THE WARMEST INTERIOR PORTIONS OF THE CENTRAL
COAST LOOK TO WARM INTO LOW-TO-UPPER 90S. THIS WILL RESULT IN
POCKETS OF MODERATE HEATRISK ACROSS THE INTERIOR. AS A RESULT, DRIER
CONDITIONS ARE FORECAST IN ELEVATIONS ABOVE THE MARINE INFLUENCES.
TOMORROW NIGHT, LOOK FOR AGAIN LESS INLAND EXTENT OF STRATUS AND THE
WARMING TREND TO CONTINUE. OVERNIGHT TEMPERATURES ARE FORECAST TO BE
IN THE MID 50S NEAR THE COAST TO LOWER 60S ACROSS THE INTERIOR.
HOWEVER, THE WARMING AIR MASS ALOFT WILL RESULT IN THE HIGHER
TERRAIN ONLY COOLING INTO THE 70S.
LONG TERM
ISSUED AT 1232 PM PDT TUE SEP 22 2026
(THURSDAY THROUGH NEXT MONDAY)
THURSDAY LOOKS TO BE THE WARMEST ACROSS THE INTERIOR WITH SIMILAR
TEMPERATURES TO WEDNESDAY ELSEWHERE. ON FRIDAY, A DEVELOPING TROUGH
OFF OF THE WEST COAST WILL RETURN RESULTING IN A COOLING TREND AND
DEEPENING OF THE MARINE LAYER. THE COOLEST CONDITIONS ARE EXPECTED
SATURDAY AND SUNDAY AS A REINFORCING TROUGH DEEPENS OFF OF THE
CALIFORNIA COAST WITH TEMPERATURES UP TO 10-15 DEG F BELOW
SEASONAL AVERAGES. TEMPERATURES APPEAR TO REBOUND CLOSER TO NORMAL
FOR THIS TIME OF YEAR EARLY NEXT WEEK AS THE TROUGH FLATTENS AND
THE 500 MB HEIGHT CLUSTERS POINT TO A BUILDING RIDGE OVER THE
WESTERN UNITED STATES.
AVIATION
(18Z TAFS)
ISSUED AT 1107 AM PDT TUE SEP 22 2026
MVFR TO IFR CEILINGS ASSOCIATED WITH THE MARINE LAYER WILL GRADUALLY
SCATTER OUT IN THE NEXT COUPLE OF HOURS, RESULTING IN WIDESPREAD VFR
CONDITIONS AT MOST TERMINALS. LOW CONFIDENCE ON WHETHER HAF WILL SEE
THE SUN AS THERE MAY BE A BRIEF PERIOD OF SCATTERED CLOUDS BEFORE
BECOMING BKN AGAIN. THE USUAL DIURNAL ONSHORE WIND PATTERN PREVAILS
THROUGH THE AFTERNOON WITH A LIGHT SOUTH TO SOUTHWEST FLOW OVERNIGHT
ACROSS OUR REGION. THE MARINE LAYER WILL COMPRESS OVERNIGHT. EXACTLY
HOW MUCH IS UNCERTAIN. MODERATE CONFIDENCE FOR STS, LVK, SJC, AND
SFO TO REMAIN VFR THROUGH THE TAF CYCLE WITH ADVERTISED SCT DECKS
EARLY WEDNESDAY MORNING. THERE IS A 60-70% CHANCE FOR APC AND OAK TO
DEVELOP BKN CEILINGS GIVEN THEIR EXPOSED LOCATIONS, THOUGH IT MAY BE
INTERMITTENT DEPENDING ON THE MARINE LAYER DEPTH TONIGHT.
VICINITY OF SFO...VFR PREVAILS THIS AFTERNOON WITH LOW TO MEDIUM
CONFIDENCE ON THE RETURN OF MVFR CEILINGS TONIGHT. SHOULD CEILINGS
DEVELOP, THEY WILL LIKELY ROLL IN AROUND THE TIME OF THE SCT DECKS
AS ADVERTISED. OAK HAS A HIGHER PROBABILITY OF DEVELOPING MVFR
CEILINGS EARLY WEDNESDAY MORNING COMPARED TO SFO. WESTERLY WINDS
INCREASE TO MODERATE THIS AFTERNOON AND EASE TO A LIGHT
SOUTHWESTERLY FLOW WEDNESDAY MORNING BEFORE INCREASING AGAIN.
SFO BRIDGE APPROACH...CURRENT SATELLITE IMAGERY SHOWS A FINAL PUSH
OF STRATUS ACROSS THE BRIDGE, BUT SHOULD BECOME VFR IN THE NEXT HOUR
OR SO. PATCHY CLOUD COVER IS POSSIBLE OVER THE EASTERN SIDE OF THE
BRIDGE TONIGHT. OTHERWISE, SIMILAR TO SFO.
MONTEREY BAY TERMINALS...BORDERLINE MVFR-IFR CEILINGS LINGER THROUGH
THE NEXT COUPLE OF HOURS WITH A BRIEF PERIOD OF VFR CONDITIONS.
MEDIUM TO HIGH CONFIDENCE FOR AN EARLY ONSET OF IFR CEILINGS AROUND
4-7 PM PDT IMPACTING MRY FIRST AND THEN SNS. LOW CONFIDENCE ON
WHETHER CEILINGS WILL DROP TO LIFR TERRITORY EARLY WEDNESDAY
MORNING. FOR NOW, THE TAF ADVERTISES BORDERLINE IFR-LIFR WITH SLIGHT
IMPACTS TO VISIBILITY DUE TO MIST AND/OR DRIZZLE. ONSHORE WINDS
INCREASE TO 7-10 KT THIS AFTERNOON AND GRADUALLY BECOME LIGHT
SOUTHERLY BREEZES OVERNIGHT.
MARINE
(TODAY THROUGH SUNDAY)
ISSUED AT 904 AM PDT TUE SEP 22 2026
FRESH NORTHWEST BREEZES WITH STRONG GUSTS GRADUALLY DIMINISH
ACROSS THE SOUTHERN COASTAL WATERS BY WEDNESDAY MORNING. WIND
DRIVEN ROUGH SEAS ABATE TO MODERATE FOR A BRIEF PERIOD WEDNESDAY
NIGHT INTO THURSDAY WITH WIDESPREAD MODERATE NORTHWEST WINDS. BY
FRIDAY, WINDS INCREASE WITH BUILDING ROUGH SEAS.
FIRE WEATHER
ISSUED AT 434 AM PDT TUE SEP 22 2026
SOLID MARINE LAYER COVERAGE ALONG THE COAST AND SALINAS VALLEY
OVERNIGHT. SOUNDING AND PROFILERS PUT THE DEPTH OF THE MARINE
LAYER AROUND THE 2,000-2,500 FOOT RANGE. DEFINITELY SOME
COMPRESSION ON THE MARINE LAYER LEADING TO DRIZZLEFEST AROUND THE
AREA. SEEING SOME REDUCED VSBY TOO, WHICH MAY LEAD TO PATCHY FOG
EARLY THIS MORNING FOR CREWS DEPARTING ICP FOR TIMBER/PLASKETT.
ABOVE THE MARINE LAYER MODERATE TO EXCELLENT HUMIDITY RECOVERY
FOR THE MOST PART WITH THE DRIEST CONDITIONS ABOVE 3,000 FEET.
OTHERWISE, STILL VALID FOR A WARMING AND DRYING TREND KICKING OFF
TUESDAY WITH TEMPERATURES UP TO 10 DEGREES ABOVE NORMAL AND AREAS
OF MODERATE HEATRISK WEDNESDAY AND THURSDAY. THE MARINE LAYER WILL
COMPRESS BELOW 1,000 FEET DURING THIS WARM-UP WITH NOCTURNAL
DRYING EXPECTED ABOVE IT.
MM
MTR WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 5 AM PDT WEDNESDAY FOR PT ARENA TO PT
REYES 0-10 NM.
SMALL CRAFT ADVISORY UNTIL 9 PM PDT THIS EVENING FOR PIGEON PT
TO PT PINOS 0-10 NM.
SMALL CRAFT ADVISORY UNTIL 3 AM PDT WEDNESDAY FOR PT PINOS TO PT
PIEDRAS BLANCAS 0-10 NM.
SMALL CRAFT ADVISORY UNTIL 3 AM PDT THURSDAY FOR PT ARENA TO PT
REYES 10-60 NM.
SMALL CRAFT ADVISORY UNTIL 5 AM PDT WEDNESDAY FOR PIGEON PT TO
PT PINOS 10-60 NM.
SHORT TERM...RGASS
LONG TERM....RGASS
AVIATION...NAVARRETE
MARINE...NAVARRETE
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