999  
FXUS66 KMTR 301150  
AFDMTR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA  
ISSUED BY NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA  
350 AM PST THU JAN 30 2025  
   
..NEW AVIATION, MARINE
 
 
   
SYNOPSIS
 
 
ISSUED AT 129 PM PST WED JAN 29 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 RECIEVE THE HIGHEST AMOUNTS OF RAIN. FORECAST RAINFALL  
AMOUNTS HAVE ALSO BEEN INCREASED FOR 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 THIS EVENING.  
 
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 HOUR, WITH INLAND AREAS CLEARING BY THE AFTERNOON. STRATUS  
CLEARING FOR THE COASTAL AREAS IS UNCERTAIN AND ITS POSSIBLE IT  
WIL BE CLOUDY ALL DAY WHICH WOULD RESULT IN LOWER THAN FCST  
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 WED 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-REZ 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
 
 
WILL BE ISSUED SHORTLY  
 

 
   
MARINE
 
 
(TODAY THROUGH NEXT TUESDAY) ISSUED AT 300 AM PST THU JAN 30 2025  
 
WINDS AND SEAS TO STAY RELATIVELY CALM AND LIGHT THROUGH FRIDAY.  
UNSETTLED WEATHER RETURNS FRIDAY INTO EARLY NEXT WEEK AS AN UPPER  
LEVEL LOW BRINGS GUSTY WINDS TO THE NORTHERN WATERS, CREATING  
HAZARDOUS CONDITIONS FOR SMALL CRAFTS. EXPECT WIDESPREAD RAIN OVER  
THE WATERS STARTING FRIDAY INTO THE WEEKEND.  
 

 
   
MTR WATCHES/WARNINGS/ADVISORIES
 
 
.TDAY...NONE.  
 

 
 

 
 
PUBLIC FORECAST: 01  
AVIATION/MARINE: 02  
 
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  
 
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