024  
FXUS66 KMTR 260506  
AFDMTR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SAN FRANCISCO CA  
906 PM PST SUN FEB 25 2024  
   
..NEW AVIATION, MARINE
 
 
   
SYNOPSIS
 
 
ISSUED AT 1113 AM PST SUN FEB 25 2024  
 
LIGHT RAIN IS EXPECTED MONDAY WITH COLDER AIR FUNNELING IN BEHIND  
THE PASSAGE OF THE COLD FRONT, RESULTING IN CHILLY MORNING  
TEMPERATURES ON TUESDAY. A DRY PERIOD WILL RESUME MIDWEEK BEFORE  
UNSETTLED WEATHER RETURNS. MORE RAIN, GUSTY WINDS, AND POTENTIAL  
MOUNTAIN SNOW ARE POSSIBLE NEXT WEEKEND.  
 

 
   
UPDATE
 
 
ISSUED AT 827 PM PST SUN FEB 25 2024  
 
A LOVELY WAY TO END THE WEEKEND, WITH TEMPERATURES BEGINNING TO  
PLATEAU IN THE 50S AFTER THE INITIAL COOLING OF NIGHTFALL. CLOUD  
COVER BUILDS OVERNIGHT ALONG WITH LIGHT SHOWERS/DRIZZLE INTO  
MONDAY MORNING. IMPACTS FROM THESE RAINS LOOK MINIMAL AND RECENT  
MODEL TRENDS CONTINUE TO LIMIT RAINFALL AMOUNTS.  
 

 
   
SHORT TERM
 
 
(THIS AFTERNOON THROUGH MONDAY)  
ISSUED AT 1113 AM PST SUN FEB 25 2024  
 
COLDER AND WETTER CONDITIONS BEING OBSERVED COMPARED TO 24 HOURS AGO  
AS WE ENTER A PERIOD OF TRANSITION WITH A PATTERN CHANGE  
UNDERWAY. FOR THE REST OF THE DAY TODAY, EXPECT MORE BENIGN  
WEATHER WITH LIGHT TO BREEZY W/SW WINDS AND COOLER HIGH TEMPS  
GENERALLY IN THE 60S ACROSS THE REGION.  
 
A WEAK COLD FRONT FROM THE PACIFIC NW WILL DROP DOWN INTO THE NORTH  
BAY BY MONDAY MORNING, SPREADING SOUTH TO THE REST OF THE BAY AREA  
BY THE AFTERNOON. IN ADDITION, A WEAKENING CIRCULATION OFF THE E  
PACIFIC WILL DRAW IN SOME MOISTURE, WHICH WILL RESULT IN LIGHT  
PRECIPITATION ACROSS THE REGION. LIGHT ACCUMULATIONS OF <0.10" ARE  
EXPECTED WITH LOCALLY HIGHER AMOUNTS IN THE COASTAL MOUNTAINS SOUTH  
OF THE MARIN HEADLANDS. OVERALL, THE MONDAY SYSTEM WILL NOT BE  
IMPACTFUL. POST-FRONTAL NORTHWESTERLY WINDS WILL GET A LITTLE BIT  
BREEZY WITH GUSTS UP TO 25 MPH NEAR THE COAST STARTING TOMORROW  
AFTERNOON. AFTER THE FRONT PASSES LATE MONDAY, COLDER AIR WILL  
FUNNEL INTO THE REGION. SEE LONG TERM DISCUSSION FOR MORE DETAILS ON  
COLD OVERNIGHT LOWS COMING UP.  
 

 
   
LONG TERM
 
 
(MONDAY NIGHT THROUGH NEXT SATURDAY)  
ISSUED AT 1113 AM PST SUN FEB 25 2024  
 
WHILE THE COLD FRONT ON MONDAY WON'T BRING A SUBSTANTIAL AMOUNT  
OF PRECIPITATION, IT WILL USHER IN COLDER WEATHER. THE 1000-500 MB  
THICKNESS WILL DROP FROM 554 DAM (MEASURED ON THE MORNING BALLOON  
SUNDAY) TO AROUND 540 DAM BY TUESDAY MORNING. THIS THINNING OF  
THE TROPOSPHERE INDICATES COOLER AVERAGE TEMPERATURES THROUGHOUT  
THE LOWER AND MIDDLE ATMOSPHERE. THERE IS SLIGHT CHANCE FOR HIGHER  
ELEVATIONS IN THE NORTH BAY TO REACH FREEZING TEMPERATURES ON  
TUESDAY MORNING AND A PRETTY GOOD CHANCE FOR THE VALLEYS TO DROP  
TO 36F OR LESS, POTENTIALLY TRIGGERING A FROST ADVISORY. THE REST  
OF THE BAY AREA IS LIKELY SAFE FROM MID-30S, BUT MANY AREAS WILL  
REACH THE UPPER-30S. THIS MAKES TUESDAY MORNING ROUGHLY 10 DEGREES  
COLDER THAN MONDAY MORNING. OTHERWISE TUESDAY WILL BE MOSTLY  
CLEAR WITH MILD AFTERNOON TEMPERATURES IN THE UPPER 50S AND LOW  
60S, WITH SOME MODERATE NORTHERLY WINDS. WEDNESDAY WILL ALSO BE  
CLEAR, DRY AND COOL. IN FACT IT WILL BE VERY SIMILAR TO TUESDAY,  
JUST A COUPLE DEGREES WARMER WITH A LITTLE LESS WIND.  
 
CONDITIONS LOOK RATHER UNSETTLED FOR LATE WEEK INTO THE WEEKEND AS A  
STRONGER STORM SYSTEM SLOWLY MIGRATES FROM THE GULF OF ALASKA  
TOWARDS THE WEST COAST. BREEZY WINDS AND HAZARDOUS MARINE CONDITIONS  
WILL EXIST, ALONG WITH PERIODS OF MODERATE RAINFALL. STORM TOTAL  
AMOUNTS ARE HOLDING STEADY FROM THE PREVIOUS FORECASTS, WITH RAIN  
SPREAD OUT OVER SEVERAL DAYS. GLOBAL MODEL ENSEMBLE MEMBERS STILL  
SUGGEST RAIN TOTALS AROUND 1-2" FOR THE LOWER ELEVATIONS FROM  
THURSDAY THROUGH SUNDAY, WITH HIGHER AMOUNTS WITHIN THE COASTAL  
RANGES. FRIDAY AND SATURDAY REMAIN THE TARGET PERIOD FOR WHEN THE  
HEAVIEST RAIN AMOUNTS ARE EXPECTED. IN CONTRAST TO ATMOSPHERIC  
RIVER TYPE STORMS THAT ARE TYPICALLY WARM AND WET WITH SOUTHERLY  
WINDS, THIS IS A COLDER SYSTEM FROM THE NORTH. TYPICALLY THESE  
SYSTEMS DON'T HAVE THE SAME MOISTURE TAP AS ARS BUT THEY BRING  
COLDER TEMPERATURES. AS SUCH SNOW LEVELS WILL LOWER THIS WEEKEND.  
SOME RIDGETOP SNOW ACCUMULATIONS ARE POSSIBLE, WITH THE GREATEST  
POTENTIAL FOR THIS OVER THE SANTA LUCIAS. THE POPULATED VALLEYS  
ARE UNLIKELY TO SEE SNOW, BUT IT WILL BE A COLD, WET, DREARY  
WEEKEND. THINK WINTER IN SEATTLE. QUITE A DIFFERENCE FROM THE  
BEAUTIFUL WEATHER WE'VE HAD THE LAST COUPLE DAYS. THIS ROLLER  
COASTER IS A REMINDER THAT SPRING IS NEARLY HERE.  
 

 
   
AVIATION
 
 
(06Z TAFS)  
ISSUED AT 901 PM PST SUN FEB 25 2024  
 
CURRENTLY VFR AT ALL TAF SITES. TOMORROW MORNING A WEAK COLD FRONT  
WILL DROP DOWN FROM THE NORTHWEST BRINGING LIGHT RAIN SHOWERS TO THE  
REGION. BEST CHANCES FOR RAIN ON STATION ARE FROM SFO SOUTHWARD.  
IMPACTS FROM THIS SYSTEM LOOK TO BE MVFR CONDITIONS AND WET RUNWAYS.  
 
VICINITY OF SFO...CURRENTLY VFR AND CALM. WINDS WILL BECOME  
SOUTHERLY LATE THIS EVENING AHEAD OF THE COLD FRONT. MONDAY'S  
PRECIPITATION WILL BE LIGHT AND SHOWERY IN NATURE. WINDS BECOME  
NORTHWESTERLY BEHIND THE COLD FRONT.  
 
SFO BRIDGE APPROACH...SIMILAR TO SFO.  
 
MONTEREY BAY TERMINALS...CURRENTLY VFR WITH BREEZY DRAINAGE FLOW  
AT BOTH TERMINALS. WINDS RETURN TO ONSHORE FLOW BY TOMORROW  
AFTERNOON. MONDAY'S PRECIPITATION WILL BE LIGHT AND SHOWERY IN  
NATURE.  
 

 
   
MARINE
 
 
(TONIGHT THROUGH NEXT FRIDAY)  
ISSUED AT 901 PM PST SUN FEB 25 2024  
 
A COLD FRONT WILL DROP DOWN FROM THE NORTHWEST MONDAY MORNING,  
BRINGING LIGHT RAIN PRIMARILY TO THE SOUTHERN WATERS, WITH WINDS  
TURNING TO BECOME NORTHERLY AND FRESH INTO THE LATER PART OF THE  
DAY. DUE TO THE FRESH TO STRONG BREEZE, SMALL CRAFT ADVISORIES  
HAVE BEEN ISSUED FOR EXPOSED COASTAL WATERS BEGINNING MONDAY  
AFTERNOON. NORTHWESTERLY SWELL CONTINUES TO MOVE THROUGH THE  
WATERS WITH A PERIOD OF ABOUT 12-14 SECONDS THROUGH MONDAY. LARGER  
NW SWELL BEGINS TO ENTER THE COASTAL WATERS TUESDAY.  
 

 
   
MTR WATCHES/WARNINGS/ADVISORIES
 
 
CA...NONE.  
PZ...SMALL CRAFT ADVISORY FROM 3 PM MONDAY TO 9 PM PST TUESDAY FOR PT  
ARENA TO PT REYES 0-10 NM.  
 
SMALL CRAFT ADVISORY FROM 3 PM MONDAY TO 3 AM PST TUESDAY FOR PT  
REYES TO PIGEON PT 0-10 NM.  
 
SMALL CRAFT ADVISORY FROM 9 PM MONDAY TO 3 AM PST TUESDAY FOR  
PIGEON PT TO PT PINOS 0-10 NM.  
 
SMALL CRAFT ADVISORY FROM 3 PM TO 9 PM PST TUESDAY FOR PIGEON PT  
TO PT PINOS 0-10 NM.  
 
SMALL CRAFT ADVISORY FROM 9 PM MONDAY TO 9 PM PST TUESDAY FOR PT  
PINOS TO PT PIEDRAS BLANCAS 0-10 NM.  
 
SMALL CRAFT ADVISORY FROM 3 PM MONDAY TO 3 AM PST WEDNESDAY FOR  
PT ARENA TO PT REYES 10-60 NM.  
 
SMALL CRAFT ADVISORY FROM 9 PM MONDAY TO 3 AM PST WEDNESDAY FOR  
PIGEON PT TO PT PINOS 10-60 NM.  
 

 
 

 
 
SHORT TERM...MCCORKLE  
LONG TERM....FLYNN  
AVIATION...SARMENT  
MARINE...SARMENT  
 
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