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FXUS66 KMTR [Monterey CA] 222006 AFDMTR ∨

FXUS66 KMTR 222006
AFDMTR [HEAD]

National Weather Service San Francisco California 1:06pm PDT Sat Mar 22 2025 ∨

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
106 PM PDT SAT MAR 22 2025 [HEAD]

New synopsis, short term, long term. ∨

...NEW SYNOPSIS, SHORT TERM, LONG TERM... [DISC]

Synopsis. Issued at 12:02pm PDT Sat Mar 22 2025 ∨

.SYNOPSIS...
ISSUED AT 1202 PM PDT SAT MAR 22 2025 [DISC]

A warming trend begins Sunday, with temperatures climbing as much as 20° above normal from Monday - Tuesday. A weak disturbance will bring cooler weather and some light rain later in the week. ∨

A WARMING TREND BEGINS SUNDAY, WITH TEMPERATURES CLIMBING AS MUCH
AS 20 DEGREES ABOVE NORMAL FROM MONDAY - TUESDAY. A WEAK
DISTURBANCE WILL BRING COOLER WEATHER AND SOME LIGHT RAIN LATER IN
THE WEEK. [DISC]

Short term. (this evening through Sunday) issued at 12:02pm PDT Sat Mar 22 2025 ∨

.SHORT TERM...
(THIS EVENING THROUGH SUNDAY)
ISSUED AT 1202 PM PDT SAT MAR 22 2025 [DISC]

We were a little surprised by the Cazadareo S-band profiler [instrument designed to measure horizontal winds directly above its location, and thus measure the vertical wind profile. Profilers operate on the same principles as Doppler radar.] this morning, which showed rain reaching the ground around 10am - 12pm. KMUX [Santa Clara/88D CA] shows decent returns in Sonoma County, and the Santa Rosa Airport was reporting light rain as of 11:53am. While there isn't much support in the model guidance, this light rain makes sense when considering the very high moisture discovered on the 12Z [5am PDT] sounding (0.98" PW [precipitable water]), combined with the short wave trough currently moving through the Bay Area. The radar shows this rain is losing organization with decreasing latitude, but we will probably still get some a few drops south of the Golden Gate and in the East Bay this afternoon. Even the more organized rain in the North Bay is more of a novelty, with very little, if any accumulation expected. Through the afternoon and evening, the trough will move inland. This will kick off a period of ridge building that will last through Sunday. That means we'll have decreasing cloud cover overnight and a beautiful, warm day on Sunday. Albeit with some moderate wind along the coast. ∨

WE WERE A LITTLE SURPRISED BY THE CAZADAREO S-BAND PROFILER THIS
MORNING, WHICH SHOWED RAIN REACHING THE GROUND AROUND 10 AM - 12
PM. KMUX SHOWS DECENT RETURNS IN SONOMA COUNTY, AND THE SANTA ROSA
AIRPORT WAS REPORTING LIGHT RAIN AS OF 1153 AM. WHILE THERE ISN`T
MUCH SUPPORT IN THE MODEL GUIDANCE, THIS LIGHT RAIN MAKES SENSE
WHEN CONSIDERING THE VERY HIGH MOISTURE DISCOVERED ON THE 12Z
SOUNDING (0.98" PW), COMBINED WITH THE SHORT WAVE TROUGH
CURRENTLY MOVING THROUGH THE BAY AREA. THE RADAR SHOWS THIS RAIN
IS LOSING ORGANIZATION WITH DECREASING LATITUDE, BUT WE WILL
PROBABLY STILL GET SOME A FEW DROPS SOUTH OF THE GOLDEN GATE AND
IN THE EAST BAY THIS AFTERNOON. EVEN THE MORE ORGANIZED RAIN IN
THE NORTH BAY IS MORE OF A NOVELTY, WITH VERY LITTLE, IF ANY
ACCUMULATION EXPECTED. THROUGH THE AFTERNOON AND EVENING, THE
TROUGH WILL MOVE INLAND. THIS WILL KICK OFF A PERIOD OF RIDGE
BUILDING THAT WILL LAST THROUGH SUNDAY. THAT MEANS WE`LL HAVE
DECREASING CLOUD COVER OVERNIGHT AND A BEAUTIFUL, WARM DAY ON
SUNDAY. ALBEIT WITH SOME MODERATE WIND ALONG THE COAST. [DISC]

Long term. (Sunday night through next Friday) issued at 12:02pm PDT Sat Mar 22 2025 ∨

.LONG TERM...
(SUNDAY NIGHT THROUGH NEXT FRIDAY)
ISSUED AT 1202 PM PDT SAT MAR 22 2025 [DISC]

By Monday morning, there's high confidence that the 850 mb temperature will climb to around 15°C, or roughly the 95th percentile for this time of year. At the same time, the ridge axis will move inland, allowing offshore winds to develop. The warm air mass, combined with adiabatic [A process which occurs with no exchange of heat between a system and its environment] heating from downslope flow, could help some coastal sites challenge daily max temperature records on Monday and Tuesday. Most areas are expected to be in the upper 70s to mid 80s from Monday–Tuesday, and the forecast has slowly been trending warmer. The SFO [San Francisco CA]-Winnemucca [NW Nevada] gradient is expected to drop to around –5 mb, which will keep the offshore winds gentle. In fact, the synoptic forcing [any mechanism that initiates or intensifies vertical motion in the atmosphere] may be overpowered by a sea breeze in the afternoon, especially along the immediate coast. If you're going to the beach, beware of the cold water (low to mid-50s), sneaker wave risk, and don't forget to bring a light Jacket, as the sea breeze wind shift could bring a chill in the afternoon. Overnight temperatures will drop into the upper 40s or low 50s, so it's a good idea to open the windows at night for those without air conditioning. ∨

BY MONDAY MORNING, THERE`S HIGH CONFIDENCE THAT THE 850 MB
TEMPERATURE WILL CLIMB TO AROUND 15C, OR ROUGHLY THE 95TH
PERCENTILE FOR THIS TIME OF YEAR. AT THE SAME TIME, THE RIDGE AXIS
WILL MOVE INLAND, ALLOWING OFFSHORE WINDS TO DEVELOP. THE WARM
AIR MASS, COMBINED WITH ADIABATIC HEATING FROM DOWNSLOPE FLOW,
COULD HELP SOME COASTAL SITES CHALLENGE DAILY MAX TEMPERATURE
RECORDS ON MONDAY AND TUESDAY. MOST AREAS ARE EXPECTED TO BE IN
THE UPPER 70S TO MID 80S FROM MONDAY-TUESDAY, AND THE FORECAST HAS
SLOWLY BEEN TRENDING WARMER. THE SFO-WMC GRADIENT IS EXPECTED TO
DROP TO AROUND -5 MB, WHICH WILL KEEP THE OFFSHORE WINDS GENTLE.
IN FACT, THE SYNOPTIC FORCING MAY BE OVERPOWERED BY A SEA BREEZE
IN THE AFTERNOON, ESPECIALLY ALONG THE IMMEDIATE COAST. IF YOU`RE
GOING TO THE BEACH, BEWARE OF THE COLD WATER (LOW TO MID-50S),
SNEAKER WAVE RISK, AND DON`T FORGET TO BRING A LIGHT JACKET, AS
THE SEA BREEZE WIND SHIFT COULD BRING A CHILL IN THE AFTERNOON.
OVERNIGHT TEMPERATURES WILL DROP INTO THE UPPER 40S OR LOW 50S, SO
IT`S A GOOD IDEA TO OPEN THE WINDOWS AT NIGHT FOR THOSE WITHOUT
AIR CONDITIONING. [DISC]

By Wednesday we will start to get some SW flow on the southern periphery of a storm targeting the Pacific Northwest. This will be followed by a fast-moving shortwave late Thursday or early Friday. These disturbances will increase cloud cover, cool things off, and bring some light rain and moderate wind to the Bay Area through Thursday. In the extended range, the ensembles are sticking to a potential atmospheric river which could stall and bring significant rain from 3/31–4/2. Uncertainty remains high with timing, intensity, targeted location, and impacts, but the trend has added a bit of confidence that something notable will happen. Be sure to stay tuned to the forecast as information will become more clear as we get closer to the event. ∨

BY WEDNESDAY WE WILL START TO GET SOME SW FLOW ON THE SOUTHERN
PERIPHERY OF A STORM TARGETING THE PACIFIC NORTHWEST. THIS WILL BE
FOLLOWED BY A FAST-MOVING SHORTWAVE LATE THURSDAY OR EARLY FRIDAY.
THESE DISTURBANCES WILL INCREASE CLOUD COVER, COOL THINGS OFF,
AND BRING SOME LIGHT RAIN AND MODERATE WIND TO THE BAY AREA
THROUGH THURSDAY. IN THE EXTENDED RANGE, THE ENSEMBLES ARE
STICKING TO A POTENTIAL ATMOSPHERIC RIVER WHICH COULD STALL AND BRING
SIGNIFICANT RAIN FROM 3/31-4/2. UNCERTAINTY REMAINS HIGH WITH
TIMING, INTENSITY, TARGETED LOCATION, AND IMPACTS, BUT THE TREND
HAS ADDED A BIT OF CONFIDENCE THAT SOMETHING NOTABLE WILL HAPPEN.
BE SURE TO STAY TUNED TO THE FORECAST AS INFORMATION WILL BECOME
MORE CLEAR AS WE GET CLOSER TO THE EVENT. [DISC]

Aviation. (18Z [11am PDT] TAFs [Terminal Aerodrome Forecasts]) issued at 10:44am PDT Sat Mar 22 2025 ∨

.AVIATION...
(18Z TAFS)
ISSUED AT 1044 AM PDT SAT MAR 22 2025 [AVIA]

Mixed bag of conditions today depending on where you are. A transient shortwave trough is kicking off light showers and increased cloudiness in the vicinity of North Bay terminals. Added VCSH [Rain Showers in the Vicinity] to account for these light, brief showers. Bay Area terminals can expect some increased cloudiness as this wave moves through as well, but shower activity is less certain further south. Currently expecting most terminals to clear to VFR [Visual Flight Rules] this afternoon, but still remain under mixed skies with mid/high level clouds. Conditions look to improve overnight with a drying trend and skies clearing out. ∨

MIXED BAG OF CONDITIONS TODAY DEPENDING ON WHERE YOU ARE. A
TRANSIENT SHORTWAVE TROUGH IS KICKING OFF LIGHT SHOWERS AND
INCREASED CLOUDINESS INVOF NORTH BAY TERMINALS. ADDED VCSH TO
ACCOUNT FOR THESE LIGHT, BRIEF SHOWERS. BAY AREA TERMINALS CAN
EXPECT SOME INCREASED CLOUDINESS AS THIS WAVE MOVES THROUGH AS
WELL, BUT SHOWER ACTIVITY IS LESS CERTAIN FURTHER SOUTH.
CURRENTLY EXPECTING MOST TERMINALS TO CLEAR TO VFR THIS AFTERNOON,
BUT STILL REMAIN UNDER MIXED SKIES WITH MID/HIGH LEVEL CLOUDS.
CONDITIONS LOOK TO IMPROVE OVERNIGHT WITH A DRYING TREND AND SKIES
CLEARING OUT. [AVI2]

Vicinity of SFO [San Francisco CA]… MVFR [Marginal Visual Flight Rules] ceilings this morning will likely give way to VFR [Visual Flight Rules] mixed skies this afternoon, but the degree of impact from the aforementioned trough is uncertain. Very slight chance that KSFO [San Francisco CA] holds on the MVFR [Marginal Visual Flight Rules] ceilings through the 20Z [1pm PDT] hour. Will continue to monitor for adjustments and the need for VCSH [Rain Showers in the Vicinity]. Some patchy ceilings building back in tonight with high confidence of VFR [Visual Flight Rules] through much of Sunday. ∨

VICINITY OF SFO...MVFR CIGS THIS MORNING WILL LIKELY GIVE WAY TO
VFR MIXED SKIES THIS AFTERNOON, BUT THE DEGREE OF IMPACT FROM THE
AFOREMENTIONED TROUGH IS UNCERTAIN. VERY SLIGHT CHANCE THAT KSFO
HOLDS ON THE MVFR CIGS THROUGH THE 20Z HOUR. WILL CONTINUE TO
MONITOR FOR ADJUSTMENTS AND THE NEED FOR VCSH. SOME PATCHY CIGS
BUILDING BACK IN TONIGHT WITH HIGH CONFIDENCE OF VFR THROUGH MUCH
OF SUNDAY. [AVI2]

SFO [San Francisco CA] bridge approach… similar to SFO [San Francisco CA]. ∨

SFO BRIDGE APPROACH...SIMILAR TO SFO. [AVI2]

Monterey Bay terminals… mostly clear conditions today as VFR [Visual Flight Rules] prevails through this evening. Not expecting the aforementioned showers to make it this far south. However, there is a better chance for MVFR [Marginal Visual Flight Rules]/IFR [Instrument Flight Rules] ceilings in the vicinity of Monterey Bay overnight tonight into Sunday morning. ∨

MONTEREY BAY TERMINALS...MOSTLY CLEAR CONDITIONS TODAY AS VFR
PREVAILS THROUGH THIS EVENING. NOT EXPECTING THE AFOREMENTIONED
SHOWERS TO MAKE IT THIS FAR SOUTH. HOWEVER, THERE IS A BETTER
CHANCE FOR MVFR/IFR CIGS INVOF MONTEREY BAY OVERNIGHT TONIGHT INTO
SUNDAY MORNING. [AVI2]

Marine. (today through Thursday) issued at 10:44am PDT Sat Mar 22 2025 ∨

.MARINE...
(TODAY THROUGH THURSDAY)
ISSUED AT 1044 AM PDT SAT MAR 22 2025 [AVIA]

The gradient between subtropical high pressure over the NE Pacific and low pressure near the California/Arizona border is supporting a fresh NW breeze in the southern waters and a gentle NW breeze in the northern waters. As this gradient tightens over the next 24 hours, the fresh breeze will expand throughout the coastal waters and persist through Monday. Moderate seas will build to very rough by Thursday due westerly swell from a strong offshore gale. ∨

THE GRADIENT BETWEEN SUBTROPICAL HIGH PRESSURE OVER THE NE PACIFIC
AND LOW PRESSURE NEAR THE CA/AZ BORDER IS SUPPORTING A FRESH NW
BREEZE IN THE SOUTHERN WATERS AND A GENTLE NW BREEZE IN THE
NORTHERN WATERS. AS THIS GRADIENT TIGHTENS OVER THE NEXT 24 HOURS,
THE FRESH BREEZE WILL EXPAND THROUGHOUT THE COASTAL WATERS AND
PERSIST THROUGH MONDAY. MODERATE SEAS WILL BUILD TO VERY ROUGH BY
THURSDAY DUE WESTERLY SWELL FROM A STRONG OFFSHORE GALE. [AVI2]

Beaches… issued at 4:50am PDT Sat Mar 22 2025 ∨

.BEACHES...
ISSUED AT 450 AM PDT SAT MAR 22 2025 [DISC]

Long period swell will arrive as early as Sunday morning, bringing an increased risk for sneaker waves through Tuesday. While the swell height will remain moderate (below 10 feet), the dominant period will exceed 15 seconds from the NW. These conditions make sneaker waves more likely. Sneaker waves get their name because the unexpectedly run farther up the beach than normal. With warm weather and good surfing conditions, the exposure to this hazard will likely be higher than normal with more people expected at the beach. The most important thing is to be aware of this hazard and to never turn your back on the ocean. ∨

LONG PERIOD SWELL WILL ARRIVE AS EARLY AS SUNDAY MORNING,
BRINGING AN INCREASED RISK FOR SNEAKER WAVES THROUGH TUESDAY.
WHILE THE SWELL HEIGHT WILL REMAIN MODERATE (BELOW 10 FEET), THE
DOMINANT PERIOD WILL EXCEED 15 SECONDS FROM THE NW. THESE
CONDITIONS MAKE SNEAKER WAVES MORE LIKELY. SNEAKER WAVES GET THEIR
NAME BECAUSE THE UNEXPECTEDLY RUN FARTHER UP THE BEACH THAN
NORMAL. WITH WARM WEATHER AND GOOD SURFING CONDITIONS, THE
EXPOSURE TO THIS HAZARD WILL LIKELY BE HIGHER THAN NORMAL WITH
MORE PEOPLE EXPECTED AT THE BEACH. THE MOST IMPORTANT THING IS TO
BE AWARE OF THIS HAZARD AND TO NEVER TURN YOUR BACK ON THE OCEAN. [DISC]

Climate. Issued at 4:10pm PDT Friday Mar 21 2025 ∨

.CLIMATE...
ISSUED AT 410 PM PDT FRI MAR 21 2025 [AVIA]

Record high temperatures at the long term stations for March 24th and 25th. ∨

RECORD HIGH TEMPERATURES AT THE LONG TERM STATIONS FOR MARCH 24TH
AND 25TH. [AVIA]

Station          March 24th          March 25th ∨

STATION          MARCH 24TH          MARCH 25TH [POPS]

Santa Rosa       91F in 1926         88F in 1952
Kentfield        88F in 1926         84F in 1997, 1930
Napa             86F in 1926         85F in 1988, 1970
Richmond         78F in 1951         83F in 1952
Livermore        82F in 2022, 2014   82F in 1997
San Francisco    82F in 1926         83F in 1952
SFO Airport      78F in 1970         85F in 1952
Redwood City     83F in 1970         84F in 1952
Half Moon Bay    73F in 1941         72F in 1969, 1947
Oakland downtown 75F in 1997         80F in 1988
San Jose         84F in 1926         84F in 1930
Salinas Airport  84F in 1951         85F in 1988
King City        87F in 1951         87F in 1988, 1930 ∨

SANTA ROSA       91F IN 1926         88F IN 1952
KENTFIELD        88F IN 1926         84F IN 1997, 1930
NAPA             86F IN 1926         85F IN 1988, 1970
RICHMOND         78F IN 1951         83F IN 1952
LIVERMORE        82F IN 2022, 2014   82F IN 1997
SAN FRANCISCO    82F IN 1926         83F IN 1952
SFO AIRPORT      78F IN 1970         85F IN 1952
REDWOOD CITY     83F IN 1970         84F IN 1952
HALF MOON BAY    73F IN 1941         72F IN 1969, 1947
OAKLAND DOWNTOWN 75F IN 1997         80F IN 1988
SAN JOSE         84F IN 1926         84F IN 1930
SALINAS AIRPORT  84F IN 1951         85F IN 1988
KING CITY        87F IN 1951         87F IN 1988, 1930 [POPS]

MTR Watches/Warnings/Advisories

California: none.
Pacific Ocean: Small Craft Advisory until 9pm PDT this evening for Monterey Bay-Pigeon Pt [Pescadero CA] to Pt Pinos [Monterey CA] 0–10 nm [11 miles]-Pt Arena [Mendocino CA] to Pt Reyes [San Francisco CA] 0–10 nm [11 miles]-Pt Reyes [San Francisco CA] to Pigeon Pt [Pescadero CA] 0–10 nm [11 miles]. ∨

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 9 PM PDT THIS EVENING FOR MRY BAY-
PIGEON PT TO PT PINOS 0-10 NM-PT ARENA TO PT REYES 0-10 NM-
PT REYES TO PIGEON PT 0-10 NM. [WARN]

Small Craft Advisory until 3am PDT Sunday for Pt Pinos [Monterey CA] to Pt Piedras Blancas [San Simeon CA] 0–10 nm [11 miles]. ∨

     SMALL CRAFT ADVISORY UNTIL 3 AM PDT SUNDAY FOR PT PINOS TO PT
PIEDRAS BLANCAS 0-10 NM. [WRN2]

Small Craft Advisory from 9pm this evening to 9am PDT Sunday for Pt Arena [Mendocino CA] to Pt Reyes [San Francisco CA] 10–60 nm [69 miles]. ∨

     SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 9 AM PDT SUNDAY
FOR PT ARENA TO PT REYES 10-60 NM. [WRN2]

Short term…flynn long term…flynn aviation…behringer marine…flynn ∨

SHORT TERM...FLYNN
LONG TERM....FLYNN
AVIATION...BEHRINGER
MARINE...FLYNN [WRN2]

VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO [LINK]

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WWW.YOUTUBE.COM/NWSBAYAREA [DISC]

Weather NWS glossary About NWS point forecasts Hourly Weather Graph Long-range forecast Radar Satellite Max Temps Graphical Forecast	Area Forecast Discussion FXUS66 KMTR [Monterey CA] 222006 AFDMTR ∨ FXUS66 KMTR 222006 AFDMTR [HEAD] National Weather Service San Francisco California 1:06pm PDT Sat Mar 22 2025 ∨ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO CA 106 PM PDT SAT MAR 22 2025 [HEAD] New synopsis, short term, long term. ∨ ...NEW SYNOPSIS, SHORT TERM, LONG TERM... [DISC] Synopsis. Issued at 12:02pm PDT Sat Mar 22 2025 ∨ .SYNOPSIS... ISSUED AT 1202 PM PDT SAT MAR 22 2025 [DISC] A warming trend begins Sunday, with temperatures climbing as much as 20° above normal from Monday - Tuesday. A weak disturbance will bring cooler weather and some light rain later in the week. ∨ A WARMING TREND BEGINS SUNDAY, WITH TEMPERATURES CLIMBING AS MUCH AS 20 DEGREES ABOVE NORMAL FROM MONDAY - TUESDAY. A WEAK DISTURBANCE WILL BRING COOLER WEATHER AND SOME LIGHT RAIN LATER IN THE WEEK. [DISC] Short term. (this evening through Sunday) issued at 12:02pm PDT Sat Mar 22 2025 ∨ .SHORT TERM... (THIS EVENING THROUGH SUNDAY) ISSUED AT 1202 PM PDT SAT MAR 22 2025 [DISC] We were a little surprised by the Cazadareo S-band profiler [instrument designed to measure horizontal winds directly above its location, and thus measure the vertical wind profile. Profilers operate on the same principles as Doppler radar.] this morning, which showed rain reaching the ground around 10am - 12pm. KMUX [Santa Clara/88D CA] shows decent returns in Sonoma County, and the Santa Rosa Airport was reporting light rain as of 11:53am. While there isn't much support in the model guidance, this light rain makes sense when considering the very high moisture discovered on the 12Z [5am PDT] sounding (0.98" PW [precipitable water]), combined with the short wave trough currently moving through the Bay Area. The radar shows this rain is losing organization with decreasing latitude, but we will probably still get some a few drops south of the Golden Gate and in the East Bay this afternoon. Even the more organized rain in the North Bay is more of a novelty, with very little, if any accumulation expected. Through the afternoon and evening, the trough will move inland. This will kick off a period of ridge building that will last through Sunday. That means we'll have decreasing cloud cover overnight and a beautiful, warm day on Sunday. Albeit with some moderate wind along the coast. ∨ WE WERE A LITTLE SURPRISED BY THE CAZADAREO S-BAND PROFILER THIS MORNING, WHICH SHOWED RAIN REACHING THE GROUND AROUND 10 AM - 12 PM. KMUX SHOWS DECENT RETURNS IN SONOMA COUNTY, AND THE SANTA ROSA AIRPORT WAS REPORTING LIGHT RAIN AS OF 1153 AM. WHILE THERE ISN`T MUCH SUPPORT IN THE MODEL GUIDANCE, THIS LIGHT RAIN MAKES SENSE WHEN CONSIDERING THE VERY HIGH MOISTURE DISCOVERED ON THE 12Z SOUNDING (0.98" PW), COMBINED WITH THE SHORT WAVE TROUGH CURRENTLY MOVING THROUGH THE BAY AREA. THE RADAR SHOWS THIS RAIN IS LOSING ORGANIZATION WITH DECREASING LATITUDE, BUT WE WILL PROBABLY STILL GET SOME A FEW DROPS SOUTH OF THE GOLDEN GATE AND IN THE EAST BAY THIS AFTERNOON. EVEN THE MORE ORGANIZED RAIN IN THE NORTH BAY IS MORE OF A NOVELTY, WITH VERY LITTLE, IF ANY ACCUMULATION EXPECTED. THROUGH THE AFTERNOON AND EVENING, THE TROUGH WILL MOVE INLAND. THIS WILL KICK OFF A PERIOD OF RIDGE BUILDING THAT WILL LAST THROUGH SUNDAY. THAT MEANS WE`LL HAVE DECREASING CLOUD COVER OVERNIGHT AND A BEAUTIFUL, WARM DAY ON SUNDAY. ALBEIT WITH SOME MODERATE WIND ALONG THE COAST. [DISC] Long term. (Sunday night through next Friday) issued at 12:02pm PDT Sat Mar 22 2025 ∨ .LONG TERM... (SUNDAY NIGHT THROUGH NEXT FRIDAY) ISSUED AT 1202 PM PDT SAT MAR 22 2025 [DISC] By Monday morning, there's high confidence that the 850 mb temperature will climb to around 15°C, or roughly the 95th percentile for this time of year. At the same time, the ridge axis will move inland, allowing offshore winds to develop. The warm air mass, combined with adiabatic [A process which occurs with no exchange of heat between a system and its environment] heating from downslope flow, could help some coastal sites challenge daily max temperature records on Monday and Tuesday. Most areas are expected to be in the upper 70s to mid 80s from Monday–Tuesday, and the forecast has slowly been trending warmer. The SFO [San Francisco CA]-Winnemucca [NW Nevada] gradient is expected to drop to around –5 mb, which will keep the offshore winds gentle. In fact, the synoptic forcing [any mechanism that initiates or intensifies vertical motion in the atmosphere] may be overpowered by a sea breeze in the afternoon, especially along the immediate coast. If you're going to the beach, beware of the cold water (low to mid-50s), sneaker wave risk, and don't forget to bring a light Jacket, as the sea breeze wind shift could bring a chill in the afternoon. Overnight temperatures will drop into the upper 40s or low 50s, so it's a good idea to open the windows at night for those without air conditioning. ∨ BY MONDAY MORNING, THERE`S HIGH CONFIDENCE THAT THE 850 MB TEMPERATURE WILL CLIMB TO AROUND 15C, OR ROUGHLY THE 95TH PERCENTILE FOR THIS TIME OF YEAR. AT THE SAME TIME, THE RIDGE AXIS WILL MOVE INLAND, ALLOWING OFFSHORE WINDS TO DEVELOP. THE WARM AIR MASS, COMBINED WITH ADIABATIC HEATING FROM DOWNSLOPE FLOW, COULD HELP SOME COASTAL SITES CHALLENGE DAILY MAX TEMPERATURE RECORDS ON MONDAY AND TUESDAY. MOST AREAS ARE EXPECTED TO BE IN THE UPPER 70S TO MID 80S FROM MONDAY-TUESDAY, AND THE FORECAST HAS SLOWLY BEEN TRENDING WARMER. THE SFO-WMC GRADIENT IS EXPECTED TO DROP TO AROUND -5 MB, WHICH WILL KEEP THE OFFSHORE WINDS GENTLE. IN FACT, THE SYNOPTIC FORCING MAY BE OVERPOWERED BY A SEA BREEZE IN THE AFTERNOON, ESPECIALLY ALONG THE IMMEDIATE COAST. IF YOU`RE GOING TO THE BEACH, BEWARE OF THE COLD WATER (LOW TO MID-50S), SNEAKER WAVE RISK, AND DON`T FORGET TO BRING A LIGHT JACKET, AS THE SEA BREEZE WIND SHIFT COULD BRING A CHILL IN THE AFTERNOON. OVERNIGHT TEMPERATURES WILL DROP INTO THE UPPER 40S OR LOW 50S, SO IT`S A GOOD IDEA TO OPEN THE WINDOWS AT NIGHT FOR THOSE WITHOUT AIR CONDITIONING. [DISC] By Wednesday we will start to get some SW flow on the southern periphery of a storm targeting the Pacific Northwest. This will be followed by a fast-moving shortwave late Thursday or early Friday. These disturbances will increase cloud cover, cool things off, and bring some light rain and moderate wind to the Bay Area through Thursday. In the extended range, the ensembles are sticking to a potential atmospheric river which could stall and bring significant rain from 3/31–4/2. Uncertainty remains high with timing, intensity, targeted location, and impacts, but the trend has added a bit of confidence that something notable will happen. Be sure to stay tuned to the forecast as information will become more clear as we get closer to the event. ∨ BY WEDNESDAY WE WILL START TO GET SOME SW FLOW ON THE SOUTHERN PERIPHERY OF A STORM TARGETING THE PACIFIC NORTHWEST. THIS WILL BE FOLLOWED BY A FAST-MOVING SHORTWAVE LATE THURSDAY OR EARLY FRIDAY. THESE DISTURBANCES WILL INCREASE CLOUD COVER, COOL THINGS OFF, AND BRING SOME LIGHT RAIN AND MODERATE WIND TO THE BAY AREA THROUGH THURSDAY. IN THE EXTENDED RANGE, THE ENSEMBLES ARE STICKING TO A POTENTIAL ATMOSPHERIC RIVER WHICH COULD STALL AND BRING SIGNIFICANT RAIN FROM 3/31-4/2. UNCERTAINTY REMAINS HIGH WITH TIMING, INTENSITY, TARGETED LOCATION, AND IMPACTS, BUT THE TREND HAS ADDED A BIT OF CONFIDENCE THAT SOMETHING NOTABLE WILL HAPPEN. BE SURE TO STAY TUNED TO THE FORECAST AS INFORMATION WILL BECOME MORE CLEAR AS WE GET CLOSER TO THE EVENT. [DISC] Aviation. (18Z [11am PDT] TAFs [Terminal Aerodrome Forecasts]) issued at 10:44am PDT Sat Mar 22 2025 ∨ .AVIATION... (18Z TAFS) ISSUED AT 1044 AM PDT SAT MAR 22 2025 [AVIA] Mixed bag of conditions today depending on where you are. A transient shortwave trough is kicking off light showers and increased cloudiness in the vicinity of North Bay terminals. Added VCSH [Rain Showers in the Vicinity] to account for these light, brief showers. Bay Area terminals can expect some increased cloudiness as this wave moves through as well, but shower activity is less certain further south. Currently expecting most terminals to clear to VFR [Visual Flight Rules] this afternoon, but still remain under mixed skies with mid/high level clouds. Conditions look to improve overnight with a drying trend and skies clearing out. ∨ MIXED BAG OF CONDITIONS TODAY DEPENDING ON WHERE YOU ARE. A TRANSIENT SHORTWAVE TROUGH IS KICKING OFF LIGHT SHOWERS AND INCREASED CLOUDINESS INVOF NORTH BAY TERMINALS. ADDED VCSH TO ACCOUNT FOR THESE LIGHT, BRIEF SHOWERS. BAY AREA TERMINALS CAN EXPECT SOME INCREASED CLOUDINESS AS THIS WAVE MOVES THROUGH AS WELL, BUT SHOWER ACTIVITY IS LESS CERTAIN FURTHER SOUTH. CURRENTLY EXPECTING MOST TERMINALS TO CLEAR TO VFR THIS AFTERNOON, BUT STILL REMAIN UNDER MIXED SKIES WITH MID/HIGH LEVEL CLOUDS. CONDITIONS LOOK TO IMPROVE OVERNIGHT WITH A DRYING TREND AND SKIES CLEARING OUT. [AVI2] Vicinity of SFO [San Francisco CA]… MVFR [Marginal Visual Flight Rules] ceilings this morning will likely give way to VFR [Visual Flight Rules] mixed skies this afternoon, but the degree of impact from the aforementioned trough is uncertain. Very slight chance that KSFO [San Francisco CA] holds on the MVFR [Marginal Visual Flight Rules] ceilings through the 20Z [1pm PDT] hour. Will continue to monitor for adjustments and the need for VCSH [Rain Showers in the Vicinity]. Some patchy ceilings building back in tonight with high confidence of VFR [Visual Flight Rules] through much of Sunday. ∨ VICINITY OF SFO...MVFR CIGS THIS MORNING WILL LIKELY GIVE WAY TO VFR MIXED SKIES THIS AFTERNOON, BUT THE DEGREE OF IMPACT FROM THE AFOREMENTIONED TROUGH IS UNCERTAIN. VERY SLIGHT CHANCE THAT KSFO HOLDS ON THE MVFR CIGS THROUGH THE 20Z HOUR. WILL CONTINUE TO MONITOR FOR ADJUSTMENTS AND THE NEED FOR VCSH. SOME PATCHY CIGS BUILDING BACK IN TONIGHT WITH HIGH CONFIDENCE OF VFR THROUGH MUCH OF SUNDAY. [AVI2] SFO [San Francisco CA] bridge approach… similar to SFO [San Francisco CA]. ∨ SFO BRIDGE APPROACH...SIMILAR TO SFO. [AVI2] Monterey Bay terminals… mostly clear conditions today as VFR [Visual Flight Rules] prevails through this evening. Not expecting the aforementioned showers to make it this far south. However, there is a better chance for MVFR [Marginal Visual Flight Rules]/IFR [Instrument Flight Rules] ceilings in the vicinity of Monterey Bay overnight tonight into Sunday morning. ∨ MONTEREY BAY TERMINALS...MOSTLY CLEAR CONDITIONS TODAY AS VFR PREVAILS THROUGH THIS EVENING. NOT EXPECTING THE AFOREMENTIONED SHOWERS TO MAKE IT THIS FAR SOUTH. HOWEVER, THERE IS A BETTER CHANCE FOR MVFR/IFR CIGS INVOF MONTEREY BAY OVERNIGHT TONIGHT INTO SUNDAY MORNING. [AVI2] Marine. (today through Thursday) issued at 10:44am PDT Sat Mar 22 2025 ∨ .MARINE... (TODAY THROUGH THURSDAY) ISSUED AT 1044 AM PDT SAT MAR 22 2025 [AVIA] The gradient between subtropical high pressure over the NE Pacific and low pressure near the California/Arizona border is supporting a fresh NW breeze in the southern waters and a gentle NW breeze in the northern waters. As this gradient tightens over the next 24 hours, the fresh breeze will expand throughout the coastal waters and persist through Monday. Moderate seas will build to very rough by Thursday due westerly swell from a strong offshore gale. ∨ THE GRADIENT BETWEEN SUBTROPICAL HIGH PRESSURE OVER THE NE PACIFIC AND LOW PRESSURE NEAR THE CA/AZ BORDER IS SUPPORTING A FRESH NW BREEZE IN THE SOUTHERN WATERS AND A GENTLE NW BREEZE IN THE NORTHERN WATERS. AS THIS GRADIENT TIGHTENS OVER THE NEXT 24 HOURS, THE FRESH BREEZE WILL EXPAND THROUGHOUT THE COASTAL WATERS AND PERSIST THROUGH MONDAY. MODERATE SEAS WILL BUILD TO VERY ROUGH BY THURSDAY DUE WESTERLY SWELL FROM A STRONG OFFSHORE GALE. [AVI2] Beaches… issued at 4:50am PDT Sat Mar 22 2025 ∨ .BEACHES... ISSUED AT 450 AM PDT SAT MAR 22 2025 [DISC] Long period swell will arrive as early as Sunday morning, bringing an increased risk for sneaker waves through Tuesday. While the swell height will remain moderate (below 10 feet), the dominant period will exceed 15 seconds from the NW. These conditions make sneaker waves more likely. Sneaker waves get their name because the unexpectedly run farther up the beach than normal. With warm weather and good surfing conditions, the exposure to this hazard will likely be higher than normal with more people expected at the beach. The most important thing is to be aware of this hazard and to never turn your back on the ocean. ∨ LONG PERIOD SWELL WILL ARRIVE AS EARLY AS SUNDAY MORNING, BRINGING AN INCREASED RISK FOR SNEAKER WAVES THROUGH TUESDAY. WHILE THE SWELL HEIGHT WILL REMAIN MODERATE (BELOW 10 FEET), THE DOMINANT PERIOD WILL EXCEED 15 SECONDS FROM THE NW. THESE CONDITIONS MAKE SNEAKER WAVES MORE LIKELY. SNEAKER WAVES GET THEIR NAME BECAUSE THE UNEXPECTEDLY RUN FARTHER UP THE BEACH THAN NORMAL. WITH WARM WEATHER AND GOOD SURFING CONDITIONS, THE EXPOSURE TO THIS HAZARD WILL LIKELY BE HIGHER THAN NORMAL WITH MORE PEOPLE EXPECTED AT THE BEACH. THE MOST IMPORTANT THING IS TO BE AWARE OF THIS HAZARD AND TO NEVER TURN YOUR BACK ON THE OCEAN. [DISC] Climate. Issued at 4:10pm PDT Friday Mar 21 2025 ∨ .CLIMATE... ISSUED AT 410 PM PDT FRI MAR 21 2025 [AVIA] Record high temperatures at the long term stations for March 24th and 25th. ∨ RECORD HIGH TEMPERATURES AT THE LONG TERM STATIONS FOR MARCH 24TH AND 25TH. [AVIA] Station March 24th March 25th ∨ STATION MARCH 24TH MARCH 25TH [POPS] Santa Rosa 91F in 1926 88F in 1952 Kentfield 88F in 1926 84F in 1997, 1930 Napa 86F in 1926 85F in 1988, 1970 Richmond 78F in 1951 83F in 1952 Livermore 82F in 2022, 2014 82F in 1997 San Francisco 82F in 1926 83F in 1952 SFO Airport 78F in 1970 85F in 1952 Redwood City 83F in 1970 84F in 1952 Half Moon Bay 73F in 1941 72F in 1969, 1947 Oakland downtown 75F in 1997 80F in 1988 San Jose 84F in 1926 84F in 1930 Salinas Airport 84F in 1951 85F in 1988 King City 87F in 1951 87F in 1988, 1930 ∨ SANTA ROSA 91F IN 1926 88F IN 1952 KENTFIELD 88F IN 1926 84F IN 1997, 1930 NAPA 86F IN 1926 85F IN 1988, 1970 RICHMOND 78F IN 1951 83F IN 1952 LIVERMORE 82F IN 2022, 2014 82F IN 1997 SAN FRANCISCO 82F IN 1926 83F IN 1952 SFO AIRPORT 78F IN 1970 85F IN 1952 REDWOOD CITY 83F IN 1970 84F IN 1952 HALF MOON BAY 73F IN 1941 72F IN 1969, 1947 OAKLAND DOWNTOWN 75F IN 1997 80F IN 1988 SAN JOSE 84F IN 1926 84F IN 1930 SALINAS AIRPORT 84F IN 1951 85F IN 1988 KING CITY 87F IN 1951 87F IN 1988, 1930 [POPS] MTR Watches/Warnings/Advisories California: none. Pacific Ocean: Small Craft Advisory until 9pm PDT this evening for Monterey Bay-Pigeon Pt [Pescadero CA] to Pt Pinos [Monterey CA] 0–10 nm [11 miles]-Pt Arena [Mendocino CA] to Pt Reyes [San Francisco CA] 0–10 nm [11 miles]-Pt Reyes [San Francisco CA] to Pigeon Pt [Pescadero CA] 0–10 nm [11 miles]. ∨ .MTR WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...SMALL CRAFT ADVISORY UNTIL 9 PM PDT THIS EVENING FOR MRY BAY- PIGEON PT TO PT PINOS 0-10 NM-PT ARENA TO PT REYES 0-10 NM- PT REYES TO PIGEON PT 0-10 NM. [WARN] Small Craft Advisory until 3am PDT Sunday for Pt Pinos [Monterey CA] to Pt Piedras Blancas [San Simeon CA] 0–10 nm [11 miles]. ∨ SMALL CRAFT ADVISORY UNTIL 3 AM PDT SUNDAY FOR PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM. [WRN2] Small Craft Advisory from 9pm this evening to 9am PDT Sunday for Pt Arena [Mendocino CA] to Pt Reyes [San Francisco CA] 10–60 nm [69 miles]. ∨ SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 9 AM PDT SUNDAY FOR PT ARENA TO PT REYES 10-60 NM. [WRN2] Short term…flynn long term…flynn aviation…behringer marine…flynn ∨ SHORT TERM...FLYNN LONG TERM....FLYNN AVIATION...BEHRINGER MARINE...FLYNN [WRN2] VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO [LINK] Follow us on Facebook, x, and YouTube at: www.facebook.com/nwsbayarea x.com/nwsbayarea www.youtube.com/nwsbayarea ∨ FOLLOW US ON FACEBOOK, X, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA X.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA [DISC]	Point Forecast Half Moon Bay CA 23 Mar 04:35pm PDT Tonight Mostly clear, with a low around 47°. NW wind around 6 mph becoming calm in the evening. Monday Sunny, with a high near 78°. Calm wind becoming NE 5 to 7 mph in the morning. Monday Night Mostly clear, with a low around 55°. North wind around 5 mph becoming calm in the evening. Tuesday Mostly sunny, with a high near 75°. Light and variable wind becoming west around 6 mph in the afternoon. Tuesday Night Mostly cloudy, with a low around 51°. SSW wind 3 to 6 mph. Wednesday Mostly cloudy, with a high near 62°. Wednesday Night A 20% chance of rain. Mostly cloudy, with a low around 48°. Thursday A slight chance of rain before 11am. Mostly sunny, with a high near 58°. Thursday Night Partly cloudy, with a low around 45°. Friday Sunny, with a high near 58°. Friday Night Partly cloudy, with a low around 43°. Saturday Partly sunny, with a high near 58°. Saturday Night A chance of rain. Mostly cloudy, with a low around 45°. Sunday Rain likely. Mostly cloudy, with a high near 57°. Tonight Mostly clear, with a low around 47. Northwest wind around 6 mph becoming calm in the evening. Monday Sunny, with a high near 78. Calm wind becoming northeast 5 to 7 mph in the morning. Monday Night Mostly clear, with a low around 55. North wind around 5 mph becoming calm in the evening. Tuesday Mostly sunny, with a high near 75. Light and variable wind becoming west around 6 mph in the afternoon. Tuesday Night Mostly cloudy, with a low around 51. South southwest wind 3 to 6 mph. Wednesday Mostly cloudy, with a high near 62. Wednesday Night A 20 percent chance of rain. Mostly cloudy, with a low around 48. Thursday A slight chance of rain before 11am. Mostly sunny, with a high near 58. Thursday Night Partly cloudy, with a low around 45. Friday Sunny, with a high near 58. Friday Night Partly cloudy, with a low around 43. Saturday Partly sunny, with a high near 58. Saturday Night A chance of rain. Mostly cloudy, with a low around 45. Sunday Rain likely. Mostly cloudy, with a high near 57.
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