288
FXUS66 KMTR 271749
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1049 AM PDT MON APR 27 2026
..NEW AVIATION, MARINE
KEY MESSAGES
UPDATED AT 1208 AM PDT MON APR 27 2026
- LIGHT RAIN AND POCKETS OF DRIZZLE POSSIBLE TODAY
- WARMING AND DRYING TREND THIS WEEK
- DISTURBED WEATHER RETURNS NEXT WEEK
SHORT TERM
ISSUED AT 1208 AM PDT MON APR 27 2026
(TODAY AND TONIGHT)
THE RADAR IS SHOWING SOME LIGHT RETURNS OVER THE MARINE ENVIRONMENT
AS WELL AS ON SOME OF THE HIGHER PEAKS, INDICATING SOME LINGERING
LIGHT RAINS ALONG WITH THE DRIZZLE ALONG THE COAST.
SOME OF THESE CHANCES WILL LINGER INTO THE DAY FOR A FEW ISOLATED
SPOTS, PARTICULARLY IN HIGHER ELEVATIONS ON THE BIG SUR COAST, THE
NORTH BAY MOUNTAINS, AND THE SANTA CRUZ MOUNTAINS. RAINFALL TOTALS
WILL BE FAIRLY LIGHT, WITH MOSTLY TRACES TO A FEW HUNDREDTHS
EXPECTED. CLOUD COVER WILL BE MORE ON THAN OFF THROUGH THE FIRST
PART OF THE DAY, BUT SUNNIER CONDITIONS ARE EXPECTED FOR THE
AFTERNOON, LEADING TO SLIGHTLY WARMER CONDITIONS THAN PREVIOUS DAYS.
THE ONSHORE FLOW AND LINGERING MOISTURE WILL PREVENT TOO MUCH OF A
WARM UP, BUT THIS WILL BE THE START OF OUR WARMING TREND.
THIS WARMING TREND WILL BE LESS PRONOUNCED FOR THE COAST AND AREAS
SLIGHTLY INLAND AS THE MARINE LAYER REBUILDS AND BECOMES BETTER-
DEFINED INTO MONDAY NIGHT AND EARLY TUESDAY. MARINE STRATUS WILL
ALSO KEEP THINGS ON THE COOLER SIDE FOR THE COAST, BUT AREAS INLAND
WILL BEGIN TO SEE MUCH WARMER AND SUNNIER CONDITIONS INTO THE WORK
WEEK.
LONG TERM
ISSUED AT 1208 AM PDT MON APR 27 2026
(TUESDAY THROUGH SUNDAY)
THE COMBINATION OF A BUILDING RIDGE TO THE NORTH AND A CUTOFF LOW TO
THE SOUTH WILL SET US UP FOR AN INTERESTING GRADIENT OF TEMPERATURES
THROUGH THE MID-WEEK AND INTO THE WEEKEND.
THE PRESSURE GRADIENT CAUSED BY THE LOW TO THE SOUTH LOOKS TO KEEP
THE MARINE ENVIRONMENT AND THE COAST BREEZY, AND WILL HELP KEEP THE
MARINE LAYER INTACT. THIS WILL RESULT IN HIGH ON THE IMMEDIATE COAST
TO STAY AROUND 60 DEGREES THROUGH THE WEEK, AND AREAS SLIGHTLY
INLAND MOSTLY STAYING IN THE 60S.
THE MORE INTERIOR AREAS WILL NOT BENEFIT FROM THE MARINE INFLUENCE,
LEADING TO WARMING AND DRYING MORE AKIN TO A TYPICAL RIDGING
PATTERN. WEDNESDAY WILL OFFER WIDESPREAD HIGHS IN THE 70S FOR AREAS
AWAY FROM THE COAST, WITH A FEW ISOLATED 80S. CONDITIONS LOOK TO
CONTINUE TO WARM FOR THE INTERIOR THROUGH FRIDAY WITH MORE AREAS
BREAKING INTO THE 80S AND POSSIBLY THE 90S IN THE SOUTHERN SALINAS
VALLEY.
MODEL AGREEMENT GOT MUCH WORSE FOR THE WEEKEND THAN LAST NIGHT, AND
THE MOVEMENT OF HIGHS AND LOWS THROUGH THE PACIFIC HAS NOT BECOME
ANY LESS COMPLICATED ACROSS ANY OF THE MAIN LONG-TERM MODELS NOR
ENSEMBLE CLUSTERS. THERE ARE HINTS TOWARD A REX-BLOCK (HIGH PRESSURE
TO THE NORTH, LOW PRESSURE TO THE SOUTH) FORMING INTO THE WEEKEND,
BUT THE POSITIONING VARY QUIET A BIT ACROSS MODELS. IN MOST CASES, IT
LOOKS LIKE THE BAY AREA AND CENTRAL COAST WILL SEE SOME COOLING DUE
TO THE LOW BING CLOSER THAN THE HIGH PRESSURE. IT COULD ALSO INCLUDE
SOME LIGHT RAIN INTO THE NEXT WORK WEEK, BUT CONFIDENCE ISN'T GREAT.
THERE ARE ALSO SOME HINTS AT THE REX-BLOCK LOSING MOMENTUM AND THIS
PATTERN ARRIVING AND EXITING AT A SLOWER PACE.
BE SURE TO KEEP CHECKING BACK IN TO SEE IF WE START MAY WITH SOME
MOISTURE.
AVIATION
(18Z TAFS)
ISSUED AT 1030 AM PDT MON APR 27 2026
IN THE WAKE OF THE SURFACE TROUGH THERE ARE NUMEROUS CUMULUS
CLOUDS ACROSS THE CWA. MOST OF THESE CLOUDS HAVE BASES IN THE LOW
VFR RANGE AND THE COVERAGE SHOULD SCATTER OUT AS THE DAY GOES ON
AND DRIER AIR CONTINUES TO FILTER IN. AS THE LOWER ATMOSPHERE
STABILIZES OVERNIGHT THERE IS A GOOD CHANCE FOR MVFR STRATUS TO
DEVELOP ACROSS ALL TERMINALS.
VICINITY OF SFO...WINDS WILL GRADUALLY INCREASE TO A MODERATE
WESTERLY BREEZE THIS AFTERNOON WITH PERSISTENT SCATTERED CLOUDS
THAT MAY OCCASIONALLY FORM A LOW VFR CEILING. THE WINDS WILL
DECREASE OVERNIGHT AND THERE IS A 50% CHANCE FOR AN MVFR CEILING
BETWEEN 12Z AND 16Z TUESDAY MORNING BEFORE THE CLOUDS CLEAR.
SFO BRIDGE APPROACH...SIMILAR TO SFO.
MONTEREY BAY TERMINALS...THERE IS STILL AN OUTSIDE CHANCE FOR A
QUICK SHOWER AT THE SOUTHERN TERMINALS, BUT THE RADAR ACTIVITY IS
GREATLY WANING. THE ASSOCIATED CEILINGS WILL LINGER THROUGH THE
DAY, BUT SHOULDN'T DROP TO MVFR UNTIL TONIGHT.
MARINE
(TODAY THROUGH SATURDAY)
ISSUED AT 1030 AM PDT MON APR 27 2026
MODERATE NW WINDS WILL PERSIST THROUGH TUESDAY BEFORE GRADUALLY
INCREASING TO A FRESH TO STRONG BREEZE WEDNESDAY THROUGH FRIDAY.
THESE STRONGER WINDS WILL BUILD ROUGH SEAS OF 8-12 FEET ACROSS
EXPOSED WATERS.
MTR WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 9 AM PDT
WEDNESDAY FOR PT ARENA TO PT REYES 10-60 NM.
SHORT TERM...MURDOCK
LONG TERM....MURDOCK
AVIATION...FLYNN
MARINE...FLYNN
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, X, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
X.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page