745
FXUS66 KMTR 172031
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
131 PM PDT Tue Jun 17 2025

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

.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.

&&

.SHORT TERM...
Issued at 1251 PM PDT Tue Jun 17 2025
(This evening through Wednesday)

Wall to wall sunshine blankets the Bay Area and Central Coast this
afternoon as stratus lurks well offshore. Lack of clouds and
increased insolation has led to warmer temperatures this
afternoon. Latest 24 hour trend shows many locations running about
3 to 6 degrees warmer, but far interior locations are as much as
10 degrees warmer than Monday. If you have a chance to spend
sometime outside today you`ll be treated to pleasant June weather.

Tonight and Wednesday - the marine layer waiting in the wings
will move inland tonight bringing low clouds and some patchy fog.
Despite the return of the marine layer upper elevations will once
again be mild and dry. Marine layer clouds will erode/roll back to
the coast early Wednesday giving way to sunny skies once again.
Wednesday will be the warmest day of the week at far interior
locations soar well into the 90s with a few spots nearing 100.
Despite the warm up HeatRisk concerns are minimal thanks to better
cooling at night. Closer to the coast will be mild, but continued
onshore flow will keep temperatures in check.

&&

.LONG TERM...
Issued at 130 PM PDT Tue Jun 17 2025
(Wednesday night through next Monday)

The temperature roller coaster continues in the Long Term. Last
weekend was cooler and then we saw warming through mid-week. The
warmup through mid-week will quickly come to an end by Thursday
and a notable cooling trend kicks in. A broad upper level trough
will move over CA by Thursday. The trough will help to deepen the
marine layer, bring 500mb heights and 850mb temperatures down.
Additional cooling is expected on Friday with highs 5 to 15
degrees below seasonal average. That translates to highs in the
upper 50s to near 70 at the coast and upper 60s to lower 80s
inland. In addition to the cooler temperatures, the passing trough
will ramp up the N-S pressure gradient. As such, cold advection
and increasing pressure gradient will lead to breezy to gusty
conditions around the region Thursday and Friday. That means
northwesterly gusts 30-40 mph with isolated 50 mph along the
coast, inland gaps/passes, inland valleys, and higher peaks. For
now will keep the marine layer in place, but sometimes when the
N-S gets this strong the marine layer gets shredded. General
upper level troughiness will persist into the weekend as the
associated parent upper level low continues to spin near the
PacNW/N Rockies.

Winds slowly ease and temperatures begin to rebound by early next
week as high pressure begins to regain control over the EPac.


&&

.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 until 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 until 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...MM
LONG TERM....MM
AVIATION...Behringer
MARINE...Behringer

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