075
FXUS66 KMTR 130752
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1252 AM PDT THU MAR 13 2025
..NEW SYNOPSIS, SHORT TERM, LONG TERM
SYNOPSIS
ISSUED AT 1251 AM PDT THU MAR 13 2025
SCATTERED SHOWERS AND A CHANCE OF THUNDERSTORMS CONTINUE INTO THE
MORNING BEFORE DIMINISHING THROUGH THE AFTERNOON. ANOTHER SYSTEM
ARRIVES FRIDAY, WITH UNSETTLED WEATHER THROUGH THE NEXT WEEK.
SHORT TERM
(TODAY AND TONIGHT)
ISSUED AT 1251 AM PDT THU MAR 13 2025
THE MAIN FRONTAL RAIN BAND HAS MOVED THROUGH THE REGION AND INTO THE
CENTRAL VALLEY AND SOUTHERN CALIFORNIA, LEAVING A PATCHWORK OF
SCATTERED SHOWERS IN ITS WAKE. THESE SHOWERS ARE EXPECTED TO
CONTINUE THROUGH THE MORNING HOURS BEFORE THE COVERAGE DECREASES IN
THE AFTERNOON. WITH THE COLD AIR ADVECTION ALLOWING LAPSE RATES TO
INCREASE, THE CHANCE FOR SOME OF THOSE SHOWERS TO TURN INTO
THUNDERSTORMS CONTINUES. THE STORM PREDICTION CENTER MAINTAINS A
GENERAL RISK OF THUNDERSTORMS THROUGH THE DAY TODAY, WITH A 20-30%
PROBABILITY OF THUNDERSTORMS THROUGH THE AFTERNOON HOURS. LOCALLY
HEAVY DOWNPOURS AND SMALL HAIL WILL BE THE MAIN THREATS. REMEMBER,
WHEN THUNDER ROARS, GO INDOORS! OR, SEE A FLASH, DASH INSIDE!
THE COLD AIR WILL ALSO ALLOW A CHANCE FOR SNOW ACROSS THE HIGHER
ELEVATIONS, WITH SNOW LEVELS DESCENDING TO AROUND 3000 FEET. CAMERAS
AT CHEWS RIDGE AND PALO ESCRITO CAPTURED SNOWFALL AT BOTH PEAKS
BEFORE SUNRISE YESTERDAY, AND CONDITIONS REMAIN FAVORABLE FOR
CONTINUING SNOWFALL IN THE HIGHER ELEVATIONS THROUGH THE MORNING.
CHILLY TEMPERATURES CONTINUE TODAY WITH MANY AREAS WITHIN THE LOWER
ELEVATIONS SEEING HIGH TEMPERATURES AROUND 8 TO 15 DEGREES BELOW
SEASONAL AVERAGES. THE INLAND VALLEYS REACH THE MID 50S, THE PACIFIC
COAST AROUND THE LOW 50S, AND PERHAPS INTO THE 40S OR THE UPPER 30S
ACROSS THE HIGHER ELEVATIONS. BREEZY NORTHWESTERLY WINDS WILL
DEVELOP THIS AFTERNOON, ALTHOUGH WE ARE NOT EXPECTING CONDITIONS
THAT WOULD REQUIRE A WIND ADVISORY TODAY, AS GUSTS GENERALLY REACH
20 TO 25 MILES PER HOUR. THE WINDS DO SHIFT TOWARDS A MORE SOUTHERLY
DIRECTION THIS EVENING, THE FIRST HARBINGER OF ANOTHER ROUND OF
STORMS.
LONG TERM
(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 1251 AM PDT THU MAR 13 2025
THE ACTIVE WEATHER PATTERN CONTINUES THROUGH THE WEEK AS A SERIES OF
UPPER LEVEL TROUGHS IMPACTS THE REGION. THE NEXT SYSTEM IS EXPECTED
ON FRIDAY AS ANOTHER FRONTAL SYSTEM ARRIVES AFTER MIDNIGHT AND MOVES
THROUGH THE REGION THROUGH FRIDAY MORNING, WITH LINGERING SHOWERS
THROUGH THE REST OF THE DAY. THIS SYSTEM IS NOT EXPECTED TO BE AS
INTENSE AS THE ONE THAT CAME THROUGH YESTERDAY, WITH RAIN TOTALS
GENERALLY 0.25-0.5" IN THE VALLEYS AND UP TO 1" ACROSS THE HIGHER
ELEVATIONS AND WIND GUSTS REACHING 30-35 MILES PER HOUR ACROSS THE
RIDGELINES.
SATURDAY SHOULD BE A BREAK FOR MOST PEOPLE, WITH THE ONLY RAIN
ACCUMULATIONS BEING A FEW HUNDREDTHS OF AN INCH IN THE SONOMA
COASTAL RANGES, BEFORE A SECOND SYSTEM COMES THROUGH THE REGION ON
SUNDAY INTO MONDAY MORNING. THE NORTH BAY LOOKS TO SEE MORE RAINFALL
FROM THIS SYSTEM WITH THE CURRENT FORECAST CALLING FOR 0.5-1" IN THE
VALLEYS, WHILE THE BAY AREA AND MONTEREY BAY REGIONS ARE ANTICIPATED
TO SEE 0.25-0.5" ACROSS THE LOWER ELEVATIONS AND UP TO 0.75" IN THE
COASTAL RANGES, WHILE LOCATIONS IN THE SOUTHERN SALINAS VALLEY MIGHT
NOT BREAK A TENTH OF AN INCH OF RAIN. THERE'S STILL SOME TIME TO
REFINE THE RAINFALL TOTALS FROM THIS SYSTEM, SO KEEP AN EYE ON THE
FORECAST UPDATES. ENSEMBLE MODEL CLUSTER ANALYSIS SUGGESTS THAT
RELATIVELY SUBTLE CHANGES IN THE POSITIONING OF THE TROUGH COULD
SWING RAINFALL TOTALS ACROSS THE NORTH BAY BY AS MUCH AS AN INCH.
BEHIND THIS SYSTEM, ENSEMBLE MODELS ARE PICKING UP ON ANOTHER UPPER
LEVEL TROUGH TOWARDS THE LATTER PART OF NEXT WEEK, BUT IT'S TOO
EARLY TO PINPOINT ANY SPECIFIC IMPACTS.
TEMPERATURES REMAIN RATHER CHILLY THROUGH THE WEEK, SLOWLY WARMING
THROUGH SUNDAY WHEN THE INTERIOR VALLEYS REACH THE SEASONAL AVERAGE
HIGHS WITHIN THE MIDDLE TO UPPER 60S BEFORE DROPPING BACK DOWN ON
MONDAY, AND WARMING BACK AGAIN INTO THE UPCOMING WEDNESDAY AND
THURSDAY WHEN THE INLAND VALLEYS AGAIN REACH THE MID TO UPPER 60S.
THE NORTH BAY SEES A MORE MUTED RISE IN TEMPERATURES WITH HIGHS IN
THE INLAND VALLEYS REACHING THE UPPER 50S TO LOWER 60S THIS WEEKEND,
WHILE COASTAL AREAS REMAIN IN THE MIDDLE 50S TO NEAR 60
THROUGHOUT.
AVIATION
(06Z TAFS)
ISSUED AT 1027 PM PDT WED MAR 12 2025
THE MAIN FRONTAL RAIN BAND IS MOVING AWAY FROM THE MAIN TERMINALS
AND GIVING WAY TO SCATTERED SHOWERS THROUGH THE NIGHT INTO THURSDAY
MORNING, WITH DECREASING COVERAGE THROUGH THE AFTERNOON. VFR WITH
MID-LEVEL CEILINGS DOMINATES BEHIND THE FRONT, WITH SOME MVFR
VISIBILITIES AND CEILINGS POSSIBLE IN THE MOST INTENSE SHOWERS.
THERE REMAINS A CHANCE (20-30% PROBABILITY) FOR THUNDERSTORMS
THROUGH THE NIGHT AND INTO THURSDAY MORNING, WITH LOCAL SMALL HAIL,
DIMINISHED VISIBILITY, AND STRONGER GUSTS. OTHERWISE, WINDS REMAIN
LIGHT THROUGH THE NIGHT BEFORE A LIGHT NORTHWESTERLY BREEZE DEVELOPS
THURSDAY AFTERNOON. WINDS DIMINISH AND TURN TO THE SOUTHWEST ON
THURSDAY EVENING IN ADVANCE OF THE SECOND FRONTAL SYSTEM, EXPECTED
TO IMPACT AFTER THE END OF THE 24-HOUR TAF PERIOD.
VICINITY OF SFO... SCATTERED SHOWERS AND A CHANCE OF THUNDERSTORMS
(20-30% PROBABILITY) THROUGH THE NIGHT INTO THURSDAY MORNING, WITH
SMALL HAIL, LOCALLY HEAVY DOWNPOURS, DECREASED VISIBILITIES, AND
ENHANCED GUSTS IF A THUNDERSTORM DEVELOPS OVER THE TERMINAL.
OTHERWISE VFR WITH MID-LEVEL CEILINGS PERSISTS THROUGH THE DAY WITH
BREEZY AND GUSTY WEST-NORTHWEST WINDS INTO THE EVENING HOURS. WINDS
WILL THEN TURN TO THE SOUTHEAST AS THE NEXT FRONTAL SYSTEM
APPROACHES AND ARRIVES EARLY FRIDAY MORNING.
SFO BRIDGE APPROACH... SIMILAR TO SFO.
MONTEREY BAY TERMINALS... SCATTERED SHOWERS AND A CHANCE OF
THUNDERSTORMS 20-30% PROBABILITY) THROUGH THE NIGHT INTO THURSDAY
MORNING. EXPECT SMALL HAIL, LOCALLY HEAVY DOWNPOURS, DECREASED
VISIBILITIES, AND ENHANCED GUSTS IF A THUNDERSTORM DEVELOPS.
OTHERWISE, VFR WITH SOME MID-LEVEL CLOUD COVER THROUGH THE TAF
PERIOD, WITH BREEZY NORTHWEST WINDS. WINDS WILL DIMINISH IN THE
EVENING AND TURN TO THE SOUTH. BEYOND THE TAF PERIOD, SNS WILL SEE
BREEZY SOUTHEAST WINDS AS THE NEXT FRONTAL SYSTEM APPROACHES EARLY
FRIDAY MORNING, WHILE MRY REMAINS RELATIVELY LIGHT INTO THE LATE
MORNING HOURS.
MARINE
(TONIGHT THROUGH NEXT TUESDAY)
ISSUED AT 1027 PM PDT WED MAR 12 2025
FRESH TO STRONG BREEZES ACROSS THE WATERS CONTINUE TO CREATE
HAZARDOUS CONDITIONS FOR SMALL CRAFT. SCATTERED SHOWERS CONTINUE
THROUGH THURSDAY WITH CHANCES FOR THUNDERSTORMS AND ASSOCIATED
STRONGER GUSTS. SEAS WILL REMAIN ROUGH INTO NEXT WEEK AS A SERIES
OF STORMS MOVES THROUGH.
BEACHES
ISSUED AT 1156 AM PDT WED MAR 12 2025
HAZARDOUS BEACH CONDITIONS ARE EXPECTED WEDNESDAY AND THURSDAY
AS MODERATE PERIOD WESTERLY SWELL BUILDS TO SUPPORT BREAKING
WAVES UP TO 15 FEET. ADDITIONAL HAZARDOUS SURF WILL BE POSSIBLE
AGAIN THIS SUNDAY. AS ALWAYS, PLEASE REMEMBER TO STAY OFF OF
ROCKS AND JETTIES, KEEP PETS ON A LEASH, AND NEVER TURN YOUR BACK
ON THE OCEAN!
MTR WATCHES/WARNINGS/ADVISORIES
CA...FROST ADVISORY FROM 11 PM THIS EVENING TO 9 AM PDT FRIDAY FOR
CAZ516>518.
PZ...SMALL CRAFT ADVISORY UNTIL 3 AM PDT EARLY THIS MORNING FOR SF
BAY N OF BAY BRIDGE.
SMALL CRAFT ADVISORY UNTIL 9 PM PDT THIS EVENING FOR MRY BAY-
PIGEON PT TO PT PINOS 0-10 NM.
GALE WARNING UNTIL 3 AM PDT EARLY THIS MORNING FOR PT ARENA TO
PT REYES 0-10 NM-PT REYES TO PIGEON PT 0-10 NM.
SMALL CRAFT ADVISORY UNTIL 3 AM PDT FRIDAY FOR PIGEON PT TO PT
PINOS 10-60 NM-PT ARENA TO PT REYES 10-60 NM-PT PINOS TO PT
PIEDRAS BLANCAS 0-10 NM.
SHORT TERM...DIALH
LONG TERM....DIALH
AVIATION...DIALH
MARINE...DIALH
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