FXUS66 KMTR 262057

AFDMTR



Area Forecast Discussion

National Weather Service San Francisco CA

157 PM PDT Thu Jun 26 2025



...New SYNOPSIS, SHORT TERM, LONG TERM...



.SYNOPSIS...

Issued at 157 PM PDT Thu Jun 26 2025



An inland warming trend Friday and Saturday as high pressure

builds and the marine layer compresses. By Sunday a weak low off

the coast will bring stronger onshore flow and deepen the marine

layer. The low will keep temperatures on the cool side of normal,

especially inland with a continued marine layer along the coast.



&&



.SHORT TERM...

(This evening through Friday)

Issued at 157 PM PDT Thu Jun 26 2025



Seasonal weather pattern continues this afternoon with sunny and

warm weather inland while a 1200 foot marine layer persists along

the coast with temps still hovering in the upper 50s and lower

60s. Still not seeing any real hot temps inland with lower 90s

confined to interior Monterey county. Northerly gradient from

SFO-ACV is now in excess of 4 mb with less stratus off the Sonoma

coast. Expect the shallow marine layer to slowly reorganize this

evening and spread into the coastal valleys overnight.



Building shortwave type ridge for Friday will continue to compress

the marine layer and lead to an inland warming trend Friday

afternoon. Expect to see lower 90s for the interior

North/South/East Bay for the first time this week. Microclimates

should be in full effect with temps ranging from 60 at Ocean Beach

to around 95 for the interior valleys. It'll finally feel a 

little more summer like inland Friday afternoon.



&&



.LONG TERM...

(Friday night through next Wednesday)

Issued at 157 PM PDT Thu Jun 26 2025



No big changes into Saturday with the ridge, so expect a shallow

marine layer and another day of inland temps in the 90s but the

coast and bays will remain mild to warm with temps running near

normal. 



By Saturday night into Sunday the models are coming into agreement

that a weak low will spin up offshore, west of San Francisco. This

will likely induce a stronger southwesterly onshore wind pattern

on Sunday (kind of like a modified southerly surge). In addition

the upper low will likely deepen the marine layer. Therefore

expect a noted cooling trend for Sunday, especially places like

Santa Cruz (north side of Monterey Bay), Napa and Sonoma valleys

where southwesterly onshore push will be efficient for pushing up

those valleys. 



Worth noting that on Sunday night the upper flow turns

southeasterly across NorCal. Gfs MUCAPE shows a few 100 J/kg but 

it doesnt align with moisture. Best forecast keeps t-storms well 

to our north and east but will monitor closely as it depends on 

exact location of upper low. Usual scenario with these setups 

would be convection over the Northern Sierra and the coastal 

ranges from Mendocino northward.



The upper low looks to take up residence for much of next week per

the latest long range models. That would mean temps running near

to a few degrees below normal for late June/early July with a

fairly deep marine layer. Thus as we head towards 4th of July not

seeing any abnormally hot weather for the Bay Area with any precip

likely staying over the Sierra and southern deserts as monsoon

moisture slowly starts to eject out of AZ and Mexico.



&&



.AVIATION...

(18Z TAFS)

Issued at 1047 AM PDT Thu Jun 26 2025



MVFR currently at MRY, OAK and SFO with clearing anticipated by 19Z-

1930Z. Low ceilings (LIFR/IFR) at HAF that may linger through much 

of the day. Winds increase this afternoon with gusty conditions at 

most terminals, easing overnight and into Friday morning. However, 

low clouds (IFR/MVFR with the greatest potential for LIFR at MRY and 

SNS) are forecast to return to the Bay Area and Monterey Bay 

terminals by late evening or early Friday morning. Any low ceilings 

that do develop will clear out late Friday morning with increasing 

onshore winds.



Vicinity of SFO...MVFR returning to VFR by late morning. Onshore 

winds increase once again this afternoon with gusts currently 

forecast to be 31 kt. Winds ease after sunset with a return to 

IFR/MVFR ceilings. Any low clouds that do develop will 

scatter out by 18Z Friday. Moderate confidence.



SFO Bridge Approach....The San Mateo Bridge Approach will likely 

remain clear though the TAF period; however, low stratus clouds 

between OAK, SFO, and northward through the Golden Gate Bridge are 

forecast to return late this evening and into Friday morning.



Monterey Bay Terminals...MVFR at MRY returning to VFR by late 

morning. Onshore winds increase this afternoon before easing late in 

the evening. IFR/MVFR ceilings likely to return late this evening 

and potentially lowering to LIFR early Friday morning. High 

confidence.



&&



.MARINE...

(Today through Tuesday)

Issued at 1047 AM PDT Thu Jun 26 2025



Fresh to strong northwesterly breezes with near-gale force gusts

will continue through Friday. Gale force gusts can be expected

near the coastal jet regions of Point Reyes and Point Sur this

afternoon and evening. Moderate to rough seas will also continue

through Friday, with northwesterly winds easing over the weekend.



&&



.MTR WATCHES/WARNINGS/ADVISORIES...

CA...Coastal Flood Advisory from 11 PM this evening to 2 AM PDT 

     Friday for CAZ006-506-508.



PZ...Small Craft Advisory until 9 PM PDT this evening for Mry Bay.



     Gale Warning until 9 PM PDT this evening for Pt Arena to Pt 

     Reyes 0-10 nm.



     Small Craft Advisory until 3 AM PDT Friday for Pigeon Pt to Pt 

     Pinos 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.



     Small Craft Advisory until 3 PM PDT this afternoon for Pt Pinos 

     to Pt Piedras Blancas 0-10 nm.



     Gale Warning until 3 AM PDT Friday for Pt Pinos to Pt Piedras 

     Blancas 0-10 nm.



     Small Craft Advisory until 3 AM PDT Saturday for Pigeon Pt to Pt 

     Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM.



&&



$$



SHORT TERM...RW

LONG TERM....RW

AVIATION...RGass

MARINE...RGass



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