Technical NOAA Weather Discussion

FXUS66 KMTR 312340
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
440 PM PDT Sun May 31 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 125 PM PDT Sun May 31 2026

 - Long period southwest swell will result in an increased risk of
   sneaker waves and rip currents through Tuesday morning

 - Continued warming for today and Monday

 - Slightly cooler temperatures for the second half of the 
   forecast

&&

.SHORT TERM...
Issued at 125 PM PDT Sun May 31 2026
(This evening through Monday)

A compressed marine layer allowed for a quick erosion of coastal 
stratus in the mid to late morning. Now we're seeing clear skies 
into the afternoon with light to moderate winds and temperatures 
already warming into the 70s in the interior.

Highs looks to stay around 60 along the immediate coast with 70s 
for the more inland areas, 80s for the interior, and a few 90s in 
the far interior. This is as a ridge pattern takes a better hold 
onto the region, calling for continued compression of the marine 
layer, weakening winds, and building temperatures.

The compressed marine layer (around 500 ft) will still have good 
moisture content overnight, leading to very low coastal clouds and 
pockets of fog. Because of how compressed the marine layer is, don't 
expect much of an inland push overnight, causing most of the region 
to stay cloud free. However, the lack of winds and a slight thermal 
belt, look to allow some of the day time heat to linger into the 
night, placing lows more into the 50s than the 40s of the last few 
nights.

This is all to say the warming trend is continuing. 

Monday will offer similar stratus clearing times, but an overall 
warmer afternoon. The coast will still be around 60 degrees and the 
slightly inland areas in the 70s, but much more of the interior will 
break into the mid to upper 80s and more areas in the far interior 
will build into the 90s.

&&

.LONG TERM...
Issued at 125 PM PDT Sun May 31 2026
(Monday night through next Saturday)

Overnight temperatures will continue the warming trend as well with 
most of the falling into the 50s Monday night into Tuesday, with a 
few 60s in the higher elevations due to the influence of the thermal 
belt.

Tuesday offers a change of pace as a weak trough disrupts the 
ridging pattern. This will push some cloud cover through the area 
and offer better onshore flow. High temperatures will see some 
modest cooling for most of the district, but mostly on the scale of 
a few degrees.

This change in flow will offer a weak cooling trend for the rest of 
the work week. More notable cooling looks to arrive as another, 
deeper trough builds. Our friends in Oregon may see some rain from 
this through, while our current chances seem to be limited to a 
coastal drizzle session.

&&

.AVIATION...
(00Z TAFS)
Issued at 439 PM PDT Sun May 31 2026

VFR through this evening before stratus returns along the coast. 
Highest confidence in stratus impacting HAF, MRY, and SNS with low 
confidence in clouds reaching SFO and OAK. Model guidance has pushed 
stratus arrival to around 08-10Z. Confidence is decent in this 
timing but will need to keep an eye on stratus developing offshore 
of the Monterey Bay for MRY and SNS. Breezy onshore winds continue 
through this evening before winds diminish overnight. Another round 
of breezy onshore winds expected during the day again tomorrow.

Vicinity of SFO...VFR. Low confidence that stratus will reach SFO 
overnight but the highest chance for CIGs would be from 12-18Z. 
Breezy westerly winds continue through this evening, ease overnight, 
and strengthen again during the afternoon/evening tomorrow. Winds 
look to peak between 15-20 knots but cannot rule out the occasional 
stronger gust.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR with IFR to LIFR CIGs expected 
overnight. The forecasted CIGs are coming in on IFR side (compared 
to MVFR earlier) for both MRY and SNS which matches well with 
observed CIGs from the previous night. There is some potential for 
lowered visibility overnight with LAMP guidance suggesting 
visibilities of less than 1SM are possible early tomorrow morning. 
Not fully onboard with low visibilities for the 00Z TAFs but will 
continue to watch the trends and adjust as needed for the 06Z TAFs. 
Breezy onshore winds are expected during this afternoon and again 
tomorrow afternoon with lighter winds overnight.

&&

.MARINE...
(Tonight through next Friday)
Issued at 259 PM PDT Sun May 31 2026

Fresh to strong northerly winds with occasional near gale force
gusts and rough seas will continue through tonight. Winds begin to
ease into Monday morning, with seas slowly subsiding as well.
Lighter north to northwest winds continue through Tuesday, with
winds increasing for the middle and later parts of the week.

&&

.BEACHES...
Issued at 1201 AM PDT Sun May 31 2026

A Beach Hazards Statement will come into effect at 5 AM today
through Tuesday morning due to an increased risk of sneaker waves
and rip currents. Long period southwest swell is approaching the 
Pacific coast, with periods of 18 to 20 seconds and a height of
around 2 feet in the open waters. These long period swells result
in increased risk of sneaker waves, potentially deadly waves which
surge much further up the beach than expected and sweep unaware
beachgoers into the ocean, and strong rip currents that can sweep
the strongest swimmers away from shore. Never turn your back to 
the ocean! Inexperienced swimmers should stay from the water. 
Observe the waves for 20 minutes before moving closer. Swim near a
lifeguard if possible, and if caught in a rip current, swim 
parallel to the coast away from the current, and then at an angle 
to shore.

DialH

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through late Monday night for CAZ006-505-
     509-529-530.

PZ...Small Craft Advisory until 3 AM PDT Monday for Pigeon Pt to Pt 
     Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt 
     Piedras Blancas 0-10 nm.

     Small Craft Advisory until 9 AM PDT Monday for Pt Arena to Pt 
     Reyes 10-60 NM.

&&

$$

SHORT TERM...Murdock
LONG TERM....Murdock
AVIATION...Kennedy
MARINE...KR

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Prepared by Boulder-Creek.com Weather at: Sun May 31 18:30:02 PDT 2026
From the National Weather Service