970
FXUS66 KMTR 092335
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
435 PM PDT SAT AUG 9 2025
..NEW AVIATION, MARINE
KEY MESSAGES
UPDATED AT 339 AM PDT SAT AUG 9 2025
- MODERATE HEATRISK CONTINUES THROUGH MONDAY FOR PORTIONS OF NORTH,
EAST, AND SOUTH BAY COUNTIES AND INTERIOR MONTEREY AND SAN BENITO
COUNTIES.
- ELEVATED FIRE WEATHER CONCERNS PERSIST GIVEN THE WARM AND DRY
CONDITIONS, WITH BREEZY WINDS EACH AFTERNOON AND EVENING.
- PATTERN CHANGE TUESDAY, WITH COOLER WEATHER AND COASTAL DRIZZLE
RETURNING TO THE FORECAST.
SHORT TERM
ISSUED AT 116 PM PDT SAT AUG 9 2025
(THIS EVENING THROUGH SUNDAY)
CLASSIC SUMMER DAY ALONG THE THE CALIFORNIA COAST, COASTAL STRATUS
WITH ABUNDANT INLAND SUNSHINE. THE STRATUS DECK ALONG THE COAST
HAS A SOUTHERLY SURGE KIND OF VIBE TO IT WITH WEAK SOUTHERLY
FLOW AND UPSTREAM/DOWNSLOPE CLEARING (MONTEREY AND N OF PT
REYES). LET'S TALK ABOUT THE INLAND SUNSHINE. WE'VE BEEN MESSAGING
A SOLID WARM UP ACROSS THE INTERIOR AND IT HAS FINALLY ARRIVED. A
QUICK PULSE CHECK OF AFTERNOON TEMPS SHOW INTERIOR LOCATIONS
MAKING A SOLID RUN AT BREAKING 100 DEGREES. PARKFIELD REACHED 101
AND BRADLEY AND POPE VALLEY BOTH REACHED 100. IF YOU HAVE OUTDOOR
PLANS AND YOU'RE IN THE INTERIOR PLEASE BE SAFE AND TAKE
APPROPRIATE HEAT SAFETY ACTIONS.
TONIGHT THROUGH SUNDAY - LET'S PUT IT ON RINSE AND REPEAT.
SHALLOW MARINE LAYER WILL MOVE INLAND AGAIN. IMPACTS WILL BE
FOG/PATCHY DRIZZLE. ONCE THE MARINE LAYER ROLLS BACK TO THE COAST
SUNDAY AFTERNOON INTERIOR LOCATIONS WILL ONCE AGAIN SOAR INTO THE
LOW 90S TO 100S.
LONG TERM
ISSUED AT 135 PM PDT SAT AUG 9 2025
(SUNDAY NIGHT THROUGH NEXT FRIDAY)
MORE OF THE SAME IS EXPECTED AS WE HEAD INTO MONDAY: COASTAL
CLOUDS WITH INLAND HEAT.
IT'S NOT UNTIL TUESDAY DO WE FINALLY SEE A BREAK IN THE INLAND
HEAT. TUESDAY WILL BE A TRANSITION TOWARD A COOLDOWN AS THE RIDGE
BREAKS DOWN AND IS REPLACED BY A TROUGH OVER THE PACNW AND THE
WEST COAST. ANOTHER TROUGH, THAT SEEMS TO BE A THEME THIS SUMMER.
WIDESPREAD COOLING IS EXPECTED BY WEDNESDAY AND LAST INTO FRIDAY.
THE DEVELOPING TROUGH WILL ALSO BRING A RETURN OF MORE WIDESPREAD
DRIZZLE...SOME GUIDANCE EVEN SUGGESTS IT COULD BE ACCUMULATING
DRIZZLE.
AVIATION
(00Z TAFS)
ISSUED AT 434 PM PDT SAT AUG 9 2025
MIX OF IFR-LIFR EXPECTED OVERNIGHT WITH VFR CONDITIONS PREVAILING AT
LVK THROUGH THE END OF THE TAF PERIOD. SATELLITE SHOWS A MUCH MORE
EXPANSIVE STRATUS FIELD TODAY THAN AT THIS TIME YESTERDAY WHICH IS
INCREASING CONFIDENCE THAT STRATUS WILL IMPACT INTERIOR SITES
TONIGHT. STRATUS WILL FILTER INTO COASTAL SITES (HAF, MRY, SNS, OAK)
THIS EVENING BEFORE RETURNING TO INTERIOR SITES (SFO, STS, APC, SJC)
OVERNIGHT. CONFIDENCE IS LOW TO MODERATE THAT STRATUS WILL REACH SJC
OVERNIGHT WITH HIGHEST CONFIDENCE IN STRATUS RETURNING EARLY
TOMORROW MORNING. STRATUS COVERAGE DISSIPATES BY MID TO LATE WITH
STRATUS LIKELY TO RETURN SHORTLY AFTER THE END OF THIS TAF PERIOD.
VICINITY OF SFO...STRATUS CHANCES INCREASE AFTER 06Z BUT CONFIDENCE
IS HIGHEST IN STRATUS FILLING IN AROUND 09Z. MODERATE CONFIDENCE
THAT CIGS WILL BE IFR WITH SOME POTENTIAL FOR LIFR CIGS TO DEVELOP
OVERNIGHT. STRATUS COVERAGE WILL DISSIPATE BY MID TO LATE MORNING
WITH VFR CONDITIONS TO PERSIST THROUGH THE REMAINDER OF THE TAF
PERIOD. MODERATE ONSHORE WINDS CONTINUE THIS AFTERNOON/EVENING AND
ARE EXPECTED TO REDEVELOP TOMORROW AFTERNOON/EVENING.
SFO BRIDGE APPROACH...STRATUS LOOKS TO FILTER IN OVER THE SF BAY
OVERNIGHT WITH STRATUS POTENTIALLY FILLING IN AS EARLY AS 06Z WHICH
MAY RESULT IN A LOSS OF VAPS TO THE SFO BRIDGE APPROACH.
MONTEREY BAY TERMINALS...HIGH CONFIDENCE THAT IFR-LIFR CIGS WILL
DEVELOP OVERNIGHT WITH DECREASES IN VISIBILITY EXPECTED EARLY
TOMORROW MORNING. CONDITIONS IMPROVE BY LATE MORNING WITH WITH VFR
CONDITIONS THROUGH THE REMAINDER OF THE TAF PERIOD. GUIDANCE
SUGGESTS AN EARLY RETURN OF STRATUS WILL TAKE PLACE AFTER THE END OF
THIS TAF PERIOD. MODERATE ONSHORE WINDS ARE EXPECTED DURING THE
AFTERNOON/EVENING TODAY AND AGAIN TOMORROW WITH WINDS PEAKING AROUND
15 KNOTS AT SNS.
MARINE
(TONIGHT THROUGH NEXT THURSDAY)
ISSUED AT 434 PM PDT SAT AUG 9 2025
A HIGH PRESSURE SYSTEM LOCATED OFF THE PACIFIC NORTHWEST WILL
GRADUALLY SHIFT WESTWARD THROUGH THE MIDDLE OF NEXT WEEK. GENTLE
TO MODERATE BREEZES WILL PREVAIL ACROSS THE CALIFORNIA COASTAL
WATERS THROUGH WEDNESDAY WITH STRONG GUSTS THROUGH THE DELTA DUE
TO THE AFTERNOON SEA BREEZE. SEAS WILL ABATE TODAY WITH WIDESPREAD
MODERATE SEAS EXPECTED BY MONDAY.
FIRE WEATHER
ISSUED AT 550 AM PDT SAT AUG 9 2025
NO MAJOR CHANGES TO THE FIRE WEATHER DISCUSSION. ELEVATED FIRE
WEATHER CONCERNS PERSIST THROUGH MONDAY GIVEN INTERIOR HEAT, LOW
HUMIDITY, AND DAILY AFTERNOON WIND GUSTS. ERC VALUES LOOK TO RISE
SOME AND THERE IS A RISK FOR FINER FUELS (GRASS OR VEG) FIRES TO
SPREAD QUICKLY IF IGNITED.
MTR WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 11 PM PDT THIS EVENING FOR SF BAY N
OF BAY BRIDGE.
SMALL CRAFT ADVISORY FROM 3 PM TO 9 PM PDT SUNDAY FOR SF BAY N
OF BAY BRIDGE.
SHORT TERM...MM
LONG TERM....MM
AVIATION...KENNEDY
MARINE...CANEPA
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