837
FXUS66 KMTR 221914
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1214 PM PDT SAT AUG 22 2026
..NEW AVIATION, MARINE
KEY MESSAGES
UPDATED AT 1200 AM PDT SAT AUG 22 2026
- TEMPERATURES NEAR TO SLIGHTLY BELOW SEASONAL AVERAGES CONTINUE
THROUGH THE NEXT WEEK
- WARM AND DRY CONDITIONS PERSIST ABOVE 1000 FEET
SHORT TERM
ISSUED AT 1200 AM PDT SAT AUG 22 2026
(TODAY AND TONIGHT)
THE SKIES ARE GENERALLY CLEAR FOR NOW WITH PATCHES OF STRATUS IN
FAVORED LOCATIONS AND SOME HIGH LEVEL CLOUDS CONTINUING TO STREAM
ACROSS THE INTERIOR. OFFSHORE, A BLOB OF COOLER AIR LURKS OFFSHORE,
EVIDENCED BY A ROBUST STRATUS DECK SET UP OFF THE NORTH BAY AND THE
SAN MATEO PENINSULA. THROUGH THE REST OF THE NIGHT, THIS STRATUS
DECK IS EXPECTED TO EXPAND TO THE COASTAL AREAS AND BUILD INLAND
THROUGH THE POST-SUNRISE HOURS WHEN THE STRATUS WILL BEGIN TO
GRADUALLY CLEAR OUT.
THE REGION REMAINS UNDER THE INFLUENCE OF THE BALANCE BETWEEN A
CUTOFF LOW LOCATED AROUND 200 MILES WEST OF CAPE BLANCO ALONG THE
SOUTHERN COAST OF OREGON, AND AN UPPER LEVEL RIDGE WITH AN AXIS
EXTENDING ALONG THE CREST OF THE ROCKY MOUNTAINS. ALTOGETHER THIS
PATTERN WILL RESULT IN TEMPERATURES WHICH ARE NEAR TO SLIGHTLY BELOW
THE SEASONAL AVERAGES, WITH HIGHS TODAY RANGING FROM THE UPPER 70S
TO THE LOWER 90S IN THE INLAND VALLEYS, THE MIDDLE 90S INTO THE
TRIPLE DIGITS FOR THE WARMEST INTERIOR SPOTS, ESPECIALLY THE
SOUTHERN TIER OF MONTEREY COUNTY, ACROSS THE 70S FOR AREAS NEAR THE
BAYS, AND THE 60S FOR AREAS ALONG THE PACIFIC COAST. THE MARINE
LAYER REMAINS RELATIVELY STABLE AT AROUND 1000-1500 FEET, WITH WARM
AND DRY CONDITIONS PERSISTING ABOVE THE MARINE LAYER INVERSION AS
RELATIVE HUMIDITY VALUES REACH THE 10-30% RANGE. WINDS REMAIN
RELATIVELY LIGHT AND DEVELOP IN AN ONSHORE FLOW PATTERN, WITH WIND
GUSTS REACHING 20 TO 30 MILES PER HOUR ALONG THE COAST, THROUGH
FAVORED GAPS AND PASSES, AND WITHIN THE NORTHERN SALINAS VALLEY.
LONG TERM
ISSUED AT 1200 AM PDT SAT AUG 22 2026
(SUNDAY THROUGH FRIDAY)
MORE OF THE SAME PATTERN IS ANTICIPATED FOR THE REST OF THE WEEK'S
FORECAST, WITH A GENERALLY SOUTHWESTERLY UPPER LEVEL FLOW OVER THE
REGION AS THE SERIES OF EASTERN PACIFIC TROUGHS CONTINUES TO BALANCE
THE RIDGE OVER THE DESERT SOUTHWEST. HIGH TEMPERATURES ARE EXPECTED
TO HOVER AROUND THE UPPER 70S TO THE LOWER 90S FOR THE INLAND
VALLEYS AND THE MIDDLE 60S TO UPPER 70S NEAR THE BAYS, WITH A SUBTLE
DROP IN THE TEMPERATURES IN THE EARLY PART OF NEXT WEEK BEFORE THE
RIDGE TRIES TO BUILD BACK TOWARDS THE WEST. AS NOTED BY THE PREVIOUS
FORECASTER, A COUPLE OF BROAD LOW PRESSURE AREAS TO THE SOUTH OF
BAJA CALIFORNIA COULD DEVELOP INTO TROPICAL SYSTEMS SOMETIME WITHIN
THE 7-DAY OUTLOOK, AND HOW THOSE SYSTEMS INTERACT WITH THE RIDGE IS
HIGHLY UNCERTAIN AT THIS TIME.
AVIATION
(18Z TAFS)
ISSUED AT 1212 PM PDT SAT AUG 22 2026
VFR THROUGH THE AFTERNOON WITH DIURNALLY INFLUENCED AND MODERATE
ONSHORE FLOW. THE OAK SOUNDING FROM THIS MORNING MEASURED THE MARINE
LAYER AT A DEPTH OF 1500 FEET WHICH IS CONSISTENT WITH THE PAST
COUPLE OF NIGHTS. HOWEVER, DUE TO DRY AIR ENTRAINMENT, STRATUS HAS
BEEN PATCHY THROUGH THE MORNING AND WILL CONTINUE TO REMAIN SO
THROUGH THE TAF PERIOD. THAT BEING SAID, AS THE UPPER LEVEL LOW
MOVES NORTHEASTWARD, HIGH PRESSURE CONTINUES TO CREEP IN WHICH WILL
SLIGHTLY COMPRESS THE MARINE LAYER. THE COMBINATION OF DRY AIR
ENTRAINMENT AND SLIGHT COMPRESSION WILL LIMIT STRATUS EXPANSION INTO
THE INTERIOR EAST AND SOUTH BAY VALLEY TERMINALS. AT SITES WHERE
STRATUS DEVELOPS, CEILINGS ARE EXPECTED TO REMAIN IFR TO MVFR. LOW
TO MEDIUM CONFIDENCE ON THE EXACT ARRIVAL OF STRATUS, THOUGH
GENERALLY EXPECT A LATER ONSET. NORTH BAY TERMINALS MAY EXPERIENCE A
WEAK, SHORT-LIVED OFFSHORE FLOW OVERNIGHT WHICH WILL FURTHER DELAY
IFR STRATUS DEVELOPMENT AND SHORTEN ITS DURATION. AS A RESULT, LOW
CONFIDENCE ON WHETHER THE MARINE LAYER WILL REACH APC.
VICINITY OF SFO...VFR CONDITIONS WITH MODERATE WESTERLIES ARE
FORECAST THROUGH THE DAY. THE INCREASED PRESSURE GRADIENT WILL
RESULT IN GUSTY ONSHORE FLOW THROUGH THE AFTERNOON AND WINDS EASE
AROUND SUNSET. THE MARINE LAYER IS EXPECTED TO BE DEEP ENOUGH TO
REACH SFO OVERNIGHT, BUT IT IS A MATTER OF WHEN. MEDIUM CONFIDENCE
ON THE EXACT TIMING AS CEILINGS MAY DEVELOP A FEW HOURS EARLIER THAN
FORECAST (09-12Z SUNDAY). STRATUS SHOULD HAVE A SIMILAR CLEARING
TIME OF 17-18Z SUNDAY.
SFO BRIDGE APPROACH...STRATUS MAY BE MORE PATCHY IN NATURE EARLY
MORNING SUNDAY. OTHERWISE, SIMILAR TO SFO.
MONTEREY BAY TERMINALS...CLEAR SKIES WITH A FEW HIGH CLOUDS PREVAIL
THROUGH THE AFTERNOON WITH ONSHORE WINDS AROUND 10 TO 15 KT. THE
OFFSHORE STRATUS FEED CONTINUES TO LOOK MESSY, THEREFORE A LATER
STRATUS ARRIVAL IS FORECAST THIS TAF PERIOD WITH MEDIUM CONFIDENCE.
IFR CEILINGS WILL IMPACT BOTH TERMINALS OVERNIGHT AND PERSIST
THROUGH THE MIDDLE OF SUNDAY MORNING.
MARINE
(TONIGHT THROUGH NEXT THURSDAY)
ISSUED AT 1212 PM PDT SAT AUG 22 2026
NORTHWEST WINDS INCREASE TO A FRESH TO STRONG BREEZE WITH SLIGHT
TO MODERATE SEAS. NEAR GALE FORCE GUSTS ARE POSSIBLE ACROSS THE
COASTAL WATERS, PARTICULARLY NEAR POINT SUR AND POINT REYES.
HAZARDOUS CONDITIONS FOR SMALL CRAFTS PERSIST TODAY FOR THE BAY
AND COASTAL WATERS. CONDITIONS ARE EXPECTED TO IMPROVE BY SUNDAY
NIGHT INTO EARLY NEXT WEEK.
MTR WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 9 PM PDT THIS EVENING FOR MRY BAY-SF
BAY N OF BAY BRIDGE.
SMALL CRAFT ADVISORY UNTIL 3 AM PDT SUNDAY FOR PT ARENA TO PT
REYES 0-10 NM-PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM-PT
REYES TO PIGEON PT 0-10 NM.
SMALL CRAFT ADVISORY UNTIL 3 AM PDT SUNDAY FOR PIGEON PT TO PT
PINOS 0-10 NM-PIGEON PT TO PT PINOS 10-60 NM-PT ARENA TO PT
REYES 10-60 NM.
SHORT TERM...DIALH
LONG TERM....DIALH
AVIATION...NAVARRETE
MARINE...NAVARRETE
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