Technical NOAA Weather Discussion

FXUS66 KMTR 081812
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1112 AM PDT Fri May 8 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1123 PM PDT Thu May 7 2026

 - Warming and drying trend will continue through the early part 
   of next week

 - Temperatures are forecast to peak on Monday

 - Moderate risk for heat-related illnesses for sensitive
   populations across the interior early next week

&&

.UPDATE...
Issued at 849 AM PDT Fri May 8 2026

Despite the marine layer around 2,000 feet in depth, low clouds are 
quickly dissipating across the interior this morning. This trend 
will continue through late morning and by the afternoon low clouds 
will be limited to coastal areas. Thus, mostly sunny conditions are 
forecast for this afternoon with the warming trend continuing. The 
ongoing forecast remains on track at this time with no updates 
anticipated this morning.  

RGass

&&

.SHORT TERM...
Issued at 1123 PM PDT Thu May 7 2026
(Tonight through Saturday)

Widespread low clouds have pushed inland from the coast, covering 
the bays and into some of the interior valleys. Expect chances for 
pockets of fog overnight, with the strongest chances in the North 
Bay. The marine layer's influence will be stronger than last night, 
that along with the blanket of lower cloud cover will keep overnight 
temperatures mild. Most areas will see lows in the 50s and upper 
40s. Only far interior valleys and higher peaks will see lows as 
cold as the mid 40s.

Friday will start on the cloudy side, and that cloud cover looks to 
linger into the late morning and even the early afternoon  for some 
areas. The duration of the cloud cover will keep coastal and 
slightly inland areas on the cooler side compared to the areas that 
stay clear. Inland cloud cover will start clearing in the mid 
morning, however areas around the bays will keep cloud cover into 
the late morning and early afternoon. Portions of the immediate 
coast looks to keep cloud cover through the day with moderate to 
breezy winds. This will keep temperatures on the coast in the lower 
60s, then the 60s and 70s for areas more inland, and into the 80s 
for areas not experiencing the morning cloud cover. A few areas in 
the far interior portions of Monterey Co look to break 90 degrees 
once again.

Friday night will see the affects of the building ridge to the north 
with a compression of the marine layer and a reduction in the 
overnight inland push of coastal stratus. This means that cloud 
cover will still be prevalent along the coast, but will struggle to 
enter the SF Bay and reach more of the inland areas. Additionally, 
the inland push of coastal stratus looks to be much later, more so 
into the night than the evening.

With a weaker marine influence, reduced cloud cover, and building 
ridge, many more of the inland areas to break into the 80s for 
Saturday. Coastal areas will stay low 60s, and the slightly inland 
areas stay in the 70s, but most areas away from the coast look to 
break 80. A few of the more inland areas look to break into the mid 
90s than previous days.

&&

.LONG TERM...
Issued at 1123 PM PDT Thu May 7 2026
(Saturday night through next Thursday)

The compression of the marine layer and building of the ridge 
continues Sunday and Monday, with Monday continuing to look like the 
hottest day of the forecast. For Monday itself: Most of the interior 
valleys look to break into the 90s with widespread 80s for all but 
the near-coastal areas seeing the 60s and 70s. 

The ridge and increasing pressure will form a thermal belt, causing 
much warmer lows on the higher peaks (60s and a few 70s) and will 
allow for those peaks to break into the 90s for Monday afternoon. 

Model trends continue to show notable cooling Tuesday, but it will 
still be on the hot side. The ridge begins to push east and a 
through deepens in the pacific leading to weak onshore winds along 
with a dissipation of the thermal belt. 

From there, models split off in the movement of said trough. Some
outputs place it in the Northwest, putting us into stronger zonal
flow. Others place it farther south into the Bay Area, leading to
drizzle and much cloudier conditions. Then there are some hits 
that the trough forms a cut off low in the middle of the Pacific, 
calling for continued weak onshore flow. Each of these scenarios 
call for a cool-down into the mid to late week, but offer fairly 
different magnitudes. Be sure to keep checking back as the 
forecast develops.

&&

.AVIATION...
(18Z TAFS)
Issued at 1029 AM PDT Fri May 8 2026

Marine layer cleared out sooner than this time yesterday at KSTS
and South Bay sites but should clear at the remaining terminals by
Noon PDT. Expect VFR conditions through this afternoon and much of
the overnight except for the Monterey Bay Terminals. The return 
of stratus later tonight is more uncertain than the previous 
couple of nights, with low confidence in the exact timing and 
extent overnight into Saturday morning. Overall, guidance is 
leaning toward cigs to develop later during the overnight, closer 
to sunrise with less of a marine layer intrusion expected and weak
fetch of offshore flow at around 2kft.

Vicinity of SFO...VFR cigs are expected by Noon PDT and should persist
through the remainder of today into early Saturday morning. Exact
timing of MVFR/IFR cigs is low confidence, with clearing expected
by late Saturday morning once they do develop, with VFR expected
for the remainder of the TAF period after clearing. 

SFO Bridge Approach...Similar as SFO.

Monterey Bay Terminals...Confidence in MVFR/IFR cigs developing
over the Monterey Bay terminals later this evening is higher than
terminals to the north. Less influence from weak offshore flow
aloft and better more persistent marine layer influence. KSNS is
expected to clear sooner with terrain influenced circulation over
Monterey Bay helping pull stratus back while maintaining coverage
over KMRY through the end of the TAF period.

&&

.MARINE...
(Today through Wednesday)
Issued at 849 AM PDT Fri May 8 2026

Fresh to strong northwest breeze continue today and will persist 
through the weekend as rough seas continue to build. Rough seas 
will begin to ease later Sunday into Monday in response to winds 
becoming moderate to fresh northerly breezes.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this 
     evening for Mry Bay.

     Small Craft Advisory from 3 PM to 9 PM PDT Saturday for Mry Bay.

     Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt 
     Reyes 0-10 nm.

     Small Craft Advisory until 9 PM PDT Sunday for Pigeon Pt to Pt 
     Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Pinos to Pt 
     Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 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...JM
MARINE...JM

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Prepared by Boulder-Creek.com Weather at: Fri May 8 12:30:04 PDT 2026
From the National Weather Service