410
FXUS66 KMTR 302022
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
1222 PM PST THU JAN 30 2025
..NEW AVIATION, MARINE
SYNOPSIS
ISSUED AT 300 AM PST THU JAN 30 2025
A PATTERN CHANGE WILL ARRIVE ON FRIDAY, LEADING TO AN EXTENDED
PERIOD OF WET WEATHER. IT IS LOOKING MORE LIKELY THAT AN
ATMOSPHERIC RIVER WILL AFFECT NORTHERN CA, INCLUDING THE BAY AREA
AND PERHAPS PORTIONS OF THE CENTRAL COAST. THE NORTH BAY WILL
LIKELY RECEIVE THE HIGHEST AMOUNTS OF RAIN. FORECAST RAINFALL
AMOUNTS HAVE ALSO BEEN INCREASED FOR THE MORE SOUTHWARD AREAS.
STAY TUNED TO THE FORECAST, AS THERE MAY WELL BE ADDITIONAL
NUANCES TO THE FORECAST RAINFALL TOTALS.
SHORT TERM
(TODAY AND TONIGHT)
ISSUED AT 300 AM PST THU JAN 30 2025
UPPER LEVEL RIDGING WILL HOLD THROUGH MUCH OF THE DAY, BUT WILL
BEGIN TO FLATTEN LATER THIS EVENING AS AN UPPER LEVEL TROF MOVES
INTO THE PAC NW. COASTAL STRATUS WILL REMAIN IN PLACE THROUGH THE
MORNING HOURS, WITH INLAND AREAS CLEARING BY THE AFTERNOON.
STRATUS CLEARING FOR THE COASTAL AREAS IS UNCERTAIN AND ITS
POSSIBLE IT WILL BE CLOUDY ALL DAY WHICH WOULD RESULT IN LOWER
THAN FORECAST TEMPERATURES. TONIGHT, SOME STRATUS MAY SLITHER
INLAND, BUT DUE TO THE PATTERN CHANGE AND APPROACHING FRONT IT
SHOULD NOT BE AS EXPANSIVE AS IT IS TODAY.
LONG TERM
(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 300 AM PST THU JAN 30 2025
THE STORM DOOR OPENS ON FRIDAY ALLOWING FOR AN ATMOSPHERIC RIVER
TO SET UP OVER THE AREA. TRENDS HAVE SHIFTED SOUTHWARD, POINTING
INITIALLY AT S OR AND N CA THE MAIN AXIS IS NOW AIMED N CA AND THE
BAY AREA. ENSEMBLES NOW SHOW MUCH OF THE BAY AREA, AND EVEN THE
CENTRAL COAST, UNDER PWATS BETWEEN .75 AND 1.25 INCHES. ENSEMBLE
BASED PRECIPITATION TOTALS HAVE ALSO INCREASED, ESPECIALLY ACROSS
THE NORTH BAY, SAN FRANCISCO AND EAST BAY AREAS. GIVEN THE INCREASED
CONFIDENCE OF HIGHER RAINFALL AMOUNTS (AND A POTENTIAL FOR EVEN
GREATER AMOUNTS), THE WPC HAS PEPPERED IN A MIX OF MARGINAL (LEVEL
1 OF 4) AND SLIGHT (LEVEL 2 OF 4) RISKS OF EXCESSIVE RAINFALL FOR
THE FRIDAY THROUGH MONDAY PERIOD (DAYS 2 TO 5). AT THE TIME OF
THIS FORECAST PACKAGE LOOK TO BE SATURDAY (DAY 3) AND MONDAY (DAY
5). FOR SATURDAY, THE WPC PLACED MUCH OF THE BAY AREA AND SANTA
CRUZ COUNTY IN A SLIGHT RISK (LEVEL 2 OF 4) FOR EXCESSIVE RAIN AND
ON MONDAY THE SLIGHT RISK ALSO INCLUDES NORTHERN SONOMA COUNTY.
THIS FORECAST WILL CONTINUE TO BE FINE TUNED AS WE GET INTO THE
HI-RES MODEL GUIDANCE TERRITORY, BE SURE TO KEEP UP WITH THE
LATEST FORECAST PRODUCTS AS RAINFALL TOTALS AND PEAKS WILL BE FINE
TUNED, WHICH COULD RESULT IN CHANGES IN TIMING AND AREAS OF THE
EXCESSIVE RAINFALL OUTLOOKS.
AVIATION
(18Z TAFS)
ISSUED AT 1159 AM PST THU JAN 30 2025
CLOUD COVER RISES OUR OF MVFR LEVELS INTO THE AFTERNOON FOR THE MORE
INTERIOR SITES BUT LOW CLOUDS LAST THROUGH THE TAF PERIOD ALONG THE
IMMEDIATE COAST. WINDS STAY LIGHT THROUGH THE DAY AND FOR MUCH OF
THE NIGHT BEFORE SOUTHERLY WINDS INCREASE AS THE NEXT STORM SYSTEM
ARRIVES. MVFR CIGS MOVE INLAND AND BECOME WIDES SPREAD INTO THE
NIGHT AS THE SYSTEM NEARS, AND CIGS LAST THROUGH THE REMAINDER FOR
ALL BUT THE MORE SOUTHERN TAF SITES. SHOWERS AND AREA OF MORE
STRATIFORM RAIN ARRIVE IN THE NORTHERN AREAS EARLY FRIDAY MORNING
AND BUILD SOUTH THROUGH THE DAY. RAIN AND MIST WILL REDUCE
VISIBILITIES AS SHOWERS CONTINUE TO BUILD INTO THE AREA.
VICINITY OF SFO...MVFR CIGS LINGER THROUGH THE FIRST HALF OF THE
AFTERNOON BEFORE SCATTERING AND RISING AS MODERATE WEST WINDS BUILD.
VFR LASTS INTO THE NIGHT BEFORE MVFR CIGS FILL AROUND THE SF BAY.
SOUTHEAST WINDS BUILD INTO EARLY FRIDAY AS PASSING SHOWERS BEGIN TO
ARRIVE. MORE CONSISTENT RAIN BEINGS TO BUILD IN THE LATE MORNING
WITH BREEZY SOUTHERLY WINDS AND SOME REDUCTION IN VISIBILITIES.
SFO BRIDGE APPROACH...SIMILAR TO SFO.
MONTEREY BAY TERMINALS...MVFR CIGS LINGER INTO THE AFTERNOON BEFORE
RISING ABOVE MVFR LEVELS AS MODERATE WEST WINDS BUILD. THESE WINDS
REDUCE INTO THE EVENING, MVFR CIGS BUILD ALONG THE COAST AND MOVE
INLAND, FILLING OVER THE MRY. THESE CIGS ARE EXPECTED TO LAST INTO
THE MID MORNING.
MARINE
(TODAY THROUGH TUESDAY)
ISSUED AT 1159 AM PST THU JAN 30 2025
WINDS AND SEAS STAY RELATIVELY CALM AND LIGHT THROUGH FRIDAY.
UNSETTLED WEATHER RETURNS EARLY FRIDAY AND WILL CONTINUE INTO
EARLY NEXT WEEK AS AN UPPER LEVEL LOW BRINGS LOCALLY GUSTY
CONDITIONS TO THE NORTHERN WATERS CREATING HAZARDOUS CONDITIONS
FOR SMALL CRAFTS. EXPECT WIDESPREAD RAIN OVER THE WATERS STARTING
FRIDAY AND PERSISTING WELL INTO THE NEXT WORK WEEK. SEAS WILL
BECOME MORE ELEVATED AS THE SYSTEM PASSES.
MTR WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 3 AM TO 9 PM PST FRIDAY FOR PT ARENA
TO PT REYES 0-10 NM-PT ARENA TO PT REYES 10-60 NM-PT REYES
TO PIGEON PT 0-10 NM.
SHORT TERM...KR
LONG TERM....KR
AVIATION...MURDOCK
MARINE...MURDOCK
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page