444
FXUS66 KMTR 171805 AAB
AFDMTR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1105 AM PDT SUN AUG 17 2025
..NEW AVIATION
KEY MESSAGES
UPDATED AT 247 AM PDT SUN AUG 17 2025
- COOL AND CLOUDY TODAY, ESPECIALLY ALONG THE COAST
- PATCHY DRIZZLE OR VERY LIGHT RAIN ALONG THE PACIFIC COAST ON
SUNDAY
- A WARMING TREND IS FORECAST STARTING TUESDAY
UPDATE
ISSUED AT 930 AM PDT SUN AUG 17 2025
FORECAST REMAINS ON TRACK FOR TODAY. NO CHANGES TO DATABASE THIS
MORNING.
OF NOTE IS AN EXTREMELY WEAK BOUNDARY TRYING TO LIMP ACROSS THE
BAY AREA, BUT WITH ALMOST NEGLIGIBLE FANFARE. THE 24 HOUR TEMP
CHANGE, AS OF 9 AM, IN SONOMA COUNTY IS PUSHING OR EXCEEDING A
DOUBLE DIGIT TEMP DROP FROM THIS TIME YESTERDAY. IN SANTA CLARA
COUNTY, STILL YET TO SEE THIS STRUGGLING BOUNDARY, TEMP CHANGE IS
A FEW DEGREES WARMER THAN THIS TIME YESTERDAY. AS THIS BOUNDARY
WASHES OUT OVER THE REGION TODAY, LOOK FOR A CAP TO THE DAYTIME
HIGHS, COOLER THAN YESTERDAY, BY GENERALLY ONLY A FEW DEGREES. AT
LEAST THIS DIFFUSE BOUNDARY IS BRINGING A LITTLE VERTICAL MIXING,
HELPING TO LIFT CLOUD DECKS AROUND THE REGION. IN ALL, IT SHOULD
BE ANOTHER AMAZING AUGUST WEATHER DAY IN THE AREA, THANKS IN PART
TO THIS LITTLE BOUNDARY THAT COULD.
SHORT TERM
ISSUED AT 247 AM PDT SUN AUG 17 2025
(TODAY AND TONIGHT)
A LITTLE LESS WET TONIGHT AS WE'RE NOT SEEING AS MUCH AS A MOISTURE
TAP AHEAD OF THE PASSING FRONT COMPARED TO LAST NIGHT. SAID COLD
FRONT IS SLOWLY EXITING THE BAY AREA AND MOVING SOUTH AND EAST WITH
A SLIGHT DRY SECTOR DIRECTLY BEHIND IT. THIS WILL LIMIT SOME OF THE
COASTAL DRIZZLE AS WELL AND CAUSE SOME MIXING OUT OF SOME OF THE
LOWER CLOUDS.
THE COOLER AND SLIGHTLY DRIER AIR FILTERING INTO THE REGION WILL
ALLOW FOR A SLIGHTLY CLEARER DAY FOR THE REGION, BUT STILL LOOKS
TO KEEP SUNDAY THE COOLEST DAY OF THE FORECAST. EXPECT HIGHS TO
RANGE FROM THE 50S ALONG THE IMMEDIATE COAST, 60S TO LOW 70S FOR
AREAS SLIGHTLY INLAND, INTO THE 80S FOR THE INTERIOR, AND THE LOW
90S FOR THE FAR INTERIOR PORTIONS OF MONTEREY CO.
CLOUD COVER DOES LOOK TO QUICKLY FILTER BACK IN TO THE SF BAY THIS
EVENING AND INTO THE NIGHT WITH THE MARINE LAYER SLIGHTLY
COMPRESSING BUT STILL SEEING A GOOD PUSH INLAND.
LONG TERM
ISSUED AT 247 AM PDT SUN AUG 17 2025
(MONDAY THROUGH SATURDAY)
THE MARINE LAYER WILL COMPRESS DUE TO OUR CHANGING UPPER LEVEL
PATTERN THAT PLACES THE REGION BACK INTO A RIDGING SET UP. MODELS
SEEM TO BE IN GOOD AGREEMENT OF STEADY WARMING INTO THE WORK WEEK
AFTER ONLY SLIGHTLY WARMER CONDITIONS FOR MONDAY. AS THE RIDGE OF
HIGH PRESSURE BUILDS, THE INTERIOR AREAS WILL REALLY SEE THE WARMING
TREND WHILE THE IMMEDIATE COAST AND ADJACENT VALLEYS SEE ONLY SLIGHT
WARMING AS THE MARINE LAYER IS SET TO COMPRESS, BUT NOT COMPLETELY
ERODE INTO THE WEEK.
A QUICK NOTE ABOUT THE COAST: THE ASTRONOMICAL SET UP WILL GIVE US A
BIT MORE MOVEMENT IN THE TIDES INTO THE NEXT WEEK. THE HIGH TIDES
WILL BE HIGHER AND THE LOW TIDES WILL BE LOWER. THIS WILL GET HIGH
TIDE LEVELS CLOSE TO COASTAL FLOODING CRITERIA, BUT NOT CROSSING THE
THRESHOLD FOR COASTAL FLOOD ADVISORIES. IT'S STILL WORTH NOTING
BECAUSE PEOPLE MAY BE HEADING TO THE SF BAY SHORELINE TO BEAT THE
HEAT IN THE NEXT FEW DAYS.
METEOROLOGIST SARMENT, TONIGHT'S MARINE FORECASTER, PROVIDED SOME
ADDITIONAL INFO:
"LOCALIZED MINOR COASTAL FLOODING WILL LIKELY OCCUR IN BAYSIDE MARIN
COUNTY THROUGH SUNDAY, AUGUST 24TH AS HIGH TIDES WILL REMAIN IN
EXCESS OF 6.0 FEET. COASTAL LOCATIONS THAT ARE DIRECTLY LOCATED NEXT
TO RICHARDSON BAY SUCH AS SAUSALITO, TAM VALLEY, MANZANITA, THE
SAUSALITO-MILL VALLEY BIKE PATH, AND THE MANZANITA PARK N RIDE CAN
EXPECT NUISANCE FLOODING WHERE TYPICALLY DRY LAND GETS WET. IMPACTS
ARE EXPECTED TO BE MINOR AT MOST - REMEMBER, DO NOT DRIVE AROUND
BARRICADES OR THROUGH WATER OF UNKNOWN DEPTH."
GETTING BACK TO THE LONGER TERM FORECAST, MODELS CONTINUE TO SHOW A
PEAKING/PLATEAUING OF THE WARMING TREND BY THE END OF THE WORK WEEK.
HIGHS LOOK TO BREAK INTO THE 100S FOR THE FAR INTERIOR WITH AROUND
105 DEGREES BEING THE WARMEST FOR THE CWA. THE COAST, HOWEVER LOOKS
TO BE PROTECTED BY A FAIRLY SHALLOW, BUT STILL INTACT MARINE LAYER
WITH HIGHS IN THE 60S AND LOW 70S.
THE BIG QUESTION IN THE LONGER TERM FORECAST IS HOW LONG THE HEAT
PERSISTS. MODELS HINT AT TINY IMPROVEMENTS TO ONSHORE FLOW, BUT
DON'T LOOK TO BREAK THE RIDGE NOR PUSH IT EAST UNTIL THE MIDDLE OF
THE NEXT WORK WEEK. THIS COULD CALL FOR SOME PROLONGED HEAT WITH
ONLY SLIGHT IMPROVEMENTS IN TEMPS. LUCKILY THAT ISN'T SET IN STONE
AND THERE COULD BE MUCH MORE PROMISING CHANGES IN THE NEXT FEW MODEL
AVIATION
(18Z TAFS)
ISSUED AT 1100 AM PDT SUN AUG 17 2025
THE MAIN THEMES FOR THIS TAF PACKAGE WILL BE A GRADUAL
IMPROVEMENT OF FLIGHT CATEGORIES THROUGH THE AFTERNOON WITH
MVFR/IFR CEILINGS RETURNING TONIGHT INTO MONDAY MORNING.
THEREAFTER, VFR SEEMS MOST PROBABLE FOR MOST SITES IN THE 17-18Z
TIME FRAME ON MONDAY. WHILE STRATUS ISN'T QUITE AS EXPANSIVE AS
YESTERDAY, A STREAM OF MOISTURE THROUGH THE GOLDEN GATE GAP WILL
CONTINUE TO SUPPORT INTERMITTENT MVFR CEILINGS AT KOAK AND KHAF
THROUGH 21-22Z. WINDS THROUGH THE DELTA AND THE VARIOUS GAPS WILL
PROMOTE W'LY WIND GUSTS TO AROUND 20-22 KNOTS (KAPC, KOAK, AND
KLVK), THOUGH A GUST OR TWO NEAR 30 KNOTS CANNOT BE DISCOUNTED.
MOISTURE WILL GRADUALLY RETURN AFTER SUNSET AND AS A RESULT,
THERE'S LOW CONFIDENCE IN THE SPECIFIC ONSET TIME OF MVFR/IFR AT
THE TERMINALS. CONFIDENCE ISN'T QUITE HIGH ENOUGH TO INCLUDE A
CEILING AT KLVK (OPTED FOR A SCT GROUP HERE) OR KSJC, SO VFR IS
ADVERTISED AT THESE SITES. IF MOISTURE RETURN IS MORE AGGRESSIVE,
THEN INCLUSION OF MVFR CIGS WILL BE WARRANTED AT THESE SITES.
CONFIDENCE IS MODERATE TO HIGH THAT VFR WILL RETURN BY 16-17Z ON
MONDAY.
VICINITY OF SFO...THE CLEARING FORECAST REMAINS A CHALLENGE AT
KSFO WITH SATELLITE TRENDS SUGGESTING AN EVENTUAL RETURN TO VFR.
AT PRESENT TIME, INTERMITTENT STRATUS MAY LINGER AS LATE AS 21Z
OVER THE TERMINAL WITH GUSTY WINDS BEING FUNNELED THROUGH THE SAN
BRUNO GAP. PEAK GUSTS ARE FORECAST NEAR 26 KNOTS, WITH A LESS THAN
20% CHANCE OF GUSTS EXCEEDING 30 KNOTS. VFR IS EXPECTED FOR THE
EVENING PUSH WITH MVFR CIGS RETURNING NEAR/JUST AFTER MIDNIGHT
MONDAY. CONFIDENCE IN THE TIMING OF MVFR CIGS IS LOW TO MEDIUM.
VFR IS ANTICIPATED TO RETURN AROUND 17Z MONDAY, THOUGH THE TIMING
MAY NEED TO BE FINE TUNED IN FUTURE TAFS.
SFO BRIDGE APPROACH...CURRENT WEB CAMERA AND SATELLITE IMAGERY
SUGGEST NON-VAPS AND INTERMITTENT CIGS ARE ANTICIPATED THROUGH AT
LEAST 21Z TODAY. CIGS RETURN AROUND 07Z WITH A POSSIBLE RETURN TO
VAPS BY 17Z MONDAY.
MONTEREY BAY TERMINALS...STRATUS DISSIPATED QUICKLY THANKS TO
SHALLOW MOISTURE AND A DIFFUSE EDDY ACROSS THE BAY. AS A RESULT,
THE RETURN OF MVFR STRATUS MAY BE DELAYED, WITH SOME GUIDANCE
SUGGESTING VFR THROUGH THE ENTIRE TAF PERIOD AT KMRY AND KSNS.
THE OVERALL CONSENSUS, HOWEVER, IS THAT CIGS AROUND FL015 WILL
INITIALLY ARRIVE AT KMRY DURING THE PRE-DAWN HOURS ON MONDAY, WITH
INTERMITTENT MVFR CIGS AT KSNS AROUND DAYBREAK. THE THREAT FOR
CIGS DIMINISHED RAPIDLY AFTER 15-16Z ON MONDAY.
MARINE
(TODAY THROUGH FRIDAY)
ISSUED AT 934 AM PDT SUN AUG 17 2025
FRESH TO STRONG BREEZES ARE ANTICIPATED, LARGELY FOR WATERS
WITHIN 10 NAUTICAL MILES OF THE SHORELINE INCLUDING SAN FRANCISCO
AND MONTEREY BAY REGIONS TODAY AND TONIGHT. THIS WILL EQUATE TO
HAZARDOUS BOATING CONDITIONS, PARTICULARLY FOR SMALLER VESSELS.
MODERATE NORTHWESTERLY SEAS ARE FORECAST THROUGH LATE MONDAY WITH
WAVE HEIGHTS SUBSIDING BRIEFLY ON TUESDAY. MODERATE TO ROUGH SEAS
ARE ADVERTISED MID-WEEK AND ONWARD AS BREEZES INCREASE. SOUTHERLY
SECONDARY SWELL WITH PERIODS OF 12 TO 16 SECONDS ARE FORECAST.
HEIGHTS ARE FORECAST TO REMAIN AT OR BELOW 2 FEET.
MTR WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 9 PM PDT THIS EVENING FOR MRY BAY-
PIGEON PT TO PT PINOS 0-10 NM-SF BAY N OF BAY BRIDGE.
SMALL CRAFT ADVISORY UNTIL 3 AM PDT MONDAY FOR PT ARENA TO PT
REYES 0-10 NM-PT REYES TO PIGEON PT 0-10 NM.
SMALL CRAFT ADVISORY UNTIL 9 AM PDT MONDAY FOR PT PINOS TO PT
PIEDRAS BLANCAS 0-10 NM.
SHORT TERM...MURDOCK
LONG TERM....MURDOCK
AVIATION...BAIN
MARINE...BAIN
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