818
FXUS66 KMTR 171747
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1047 AM PDT Tue Jun 17 2025

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 305 AM PDT Tue Jun 17 2025

Quiet weather continues with a slight warmup today and tomorrow,
with temperatures gradually falling back to near normal or slightly
below normal for the end of the week and weekend.

&&

.UPDATE...
Issued at 955 AM PDT Tue Jun 17 2025

If you were up early this morning you saw the sunrise with no
clouds. We had a little bit of a break from the June Gloom this
morning as marine layer stratus pretty much eroded. There was one
exception, there was a patch of low clouds swirling around
Monterey Bay near Moss Landing. Latest satellite imagery does show
this patch of low clouds is slowly thinning. Subtle cooling aloft
likely contributed to less clouds this morning - simply put
weakened the marine layer inversion.

No update needed this morning. Aside from some afternoon breezy
onshore flow today will feature chamber of commerce weather -
sunny skies and milder temperatures.

If you`re a fan of the marine layer and like the June Gloom have
no fear, it`s lurking off the coast. Satellite imagery shows it`s
about 60 miles off the coast and it`s forecast to move back inland
tonight.

MM

&&

.SHORT TERM...
(Today and tonight)
Issued at 305 AM PDT Tue Jun 17 2025

Temperatures warm to slightly above normal today and tomorrow with
progressive upper level shortwave ridging across our area today. Very
dry air above the marine layer remains in place helping to limit low
stratus over our coastal areas, with bright sunshine inland. As the
upper ridging shifts east, zonal flow sets up across our area late
tonight when the marine layer deepens with more widespread coastal
low marine layer stratus expected to return overnight into early
Wednesday morning.

&&

.LONG TERM...
(Wednesday through Monday)
Issued at 305 AM PDT Tue Jun 17 2025

Primarily zonal upper flow across our area on Wednesday will result
in the warmest day of the week before a deepening trough leads to
height falls, cooler temperatures and a more robust marine layer
intruding farther inland for Thursday and beyond. Temperatures will
cool back down to seasonal averages or slightly below. The upper low
over the Pacific Northwest will gradually shift inland on Friday
into the weekend. Gusty onshore flow for the end of the week and
weekend will lead to winds up to 40 MPH at times for higher
elevations, passes and gaps on Saturday, easing Saturday night.

&&

.AVIATION...
(18Z TAFS)
Issued at 1040 AM PDT Tue Jun 17 2025

Severe clear for most areas today as VFR prevails into this
evening. Marine stratus makes a come back this evening, but only
isolated locations along the coast and immediate Bay Area. Marine
layer compression due to high pressure aloft will help keep cloud
cover from penetrating too far inland or around terrain barriers.

Vicinity of SFO...VFR with gusty NW winds through this afternoon.
Stratus makes a return tonight, most likely after midnight.
Unclear how much coverage will affect the terminal, so left a SCT
group in TAF for now. At any rate, clearing anticipated to be
fairly quick Wednesday as the cloud cover mixes out by the 16Z
hour.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Clear with breezy onshore flow through
today. Return of marine stratus tonight under a compressed marine
layer mean lower CIGs and potential for areas of lower VIS.
Expecting IFR CIGs along coastal areas around midnight. A bit more
uncertain on the clearing time Wednesday. Should start to mix out
by the 17Z hour, but could be a slower process compared to the
past few days.

&&

.MARINE...
(Today through Sunday)
Issued at 1040 AM PDT Tue Jun 17 2025

Gusty northwesterly winds and moderate to rough seas continue
across  most of the coastal waters. Winds will continue to
strengthen and  significant wave heights will build starting mid
week, remaining  elevated through early next week. Gale Warnings
in effect for the coastal jet areas south of Point Reyes and Point
Sur.

&&

.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 until 3 PM PDT this afternoon for Pt Arena
     to Pt Reyes 0-10 nm.

     Gale Warning from 3 PM this afternoon to 9 PM PDT this evening
     for Pt Arena to Pt Reyes 0-10 nm.

     Small Craft Advisory until 3 PM PDT Wednesday for Pigeon Pt to
     Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Reyes to
     Pigeon Pt 0-10 nm.

     Gale Warning until 3 AM PDT Wednesday for Pt Pinos to Pt Piedras
     Blancas 0-10 nm.

     Small Craft Advisory until 9 PM PDT this evening for Pt Arena to
     Pt Reyes 10-60 NM.

     Gale Warning from 9 PM this evening to 3 PM PDT Wednesday for Pt
     Arena to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...JM
LONG TERM....JM
AVIATION...Behringer
MARINE...Behringer

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