870
FXUS66 KMTR 180551
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1051 PM PDT Mon Jun 17 2024

...New AVIATION...

.SYNOPSIS...
Issued at 153 PM PDT Mon Jun 17 2024

Dry and breezy conditions continue into Monday night. Better
onshore flow and moisture return by midweek. Another warming trend
on the way for the upcoming weekend.

&&

.UPDATE...
Issued at 836 PM PDT Mon Jun 17 2024

The Red Flag Warning that was in effect for the North Bay Interior
Mountains was allowed to expire at 8 PM this evening as relative
humidity values over the region increase to 35-45 percent overnight
and wind speeds reduce. However, while some moistening will occur
tomorrow, there remains an elevated fire weather threat through
Tuesday away from the immediate coastline/bayshore as breezy onshore
flow persists. Smoke from the Sites Fire Colusa County is moving
over the North Bay and part of the Bay Area this evening as
transport winds over that region are out of the northeast. The
ongoing forecast remains on track with no updates anticipated at
this time.

&&

.SHORT TERM...
(This evening through Tuesday)
Issued at 153 PM PDT Mon Jun 17 2024

Gusty northwest winds continue to mix down toward the surface this
afternoon, as high as 30 mph in some of our higher locations over the
interior coastal ranges and passes. The gusty winds combined with a
dry air mass producing min RH values as low as 10 percent will
persist for the remainder of this afternoon into the evening hours.
A Red Flag Warning remains in effect until 8pm for the North Bay
Interior Mountains in Napa county. A positively tilted upper level
trough will keep winds elevated with respect to the normal
diurnal trend overnight into Tuesday. Embedded weak shortwave
ridging will help to ease surface winds Tuesday, especially inland
away from the coast, however the Salinas Valley will reamin
breezy as onshore northwest surface flow channels inland.
Temperatures will remain near seasonal averages through midweek.

&&

.LONG TERM...
(Tuesday night through next Sunday)
Issued at 145 PM PDT Mon Jun 17 2024

A warm up continues to highlight the extended forecast. Persistent
upper level troughing over our region begins to shift east and
flatten late Thursday into early Friday, continuing into the
weekend. A weak ridge begins to build with the ridge axis just to
our east over the Sierra Mountains Friday afternoon. An increase
in heights and thickness will allow another round of heat to
build, especially the farther you move inland from coastal areas.
Elevated areas of southern Monterey and San Benito county may see
triple digit heat, along with portions of Contra Costa and Alameda
county to the north on Saturday, which should be the peak of this
round of heat.

&&

.AVIATION...
(06Z TAFS)
Issued at 1034 PM PDT Mon Jun 17 2024

VFR through the TAF period. Winds weaken into the late night
becoming light. Winds stay light into the late morning before
moderate to breezy winds arrive into Tuesday afternoon. Smoke from
fires to the north could cause some haze and smoke to filter into
the North Bay and around the SF Bay, but visibilities don`t look
to be greatly affected. Winds will reduce into Tuesday evening.

Vicinity of SFO...VFR through the TAF period. Winds reduce into
the night becoming light to moderate. Another round of breezy to gusty
winds starts building in the early afternoon with peak gusts
expected to be around 28 kts. These stronger gusts last into the
night. Gusts stop but moderate winds last into late Tuesday night.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR through the TAF period. Light to
moderate winds last through the late morning before more moderate
westerly winds arrive. Winds at the terminals reduce into Tuesday
night.


&&

.MARINE...
(Tonight through next Sunday)
Issued at 836 PM PDT Mon Jun 17 2024

Widespread strong northerly/northwesterly breezes with near gale-
force gusts will persist through Wednesday. Gusty winds will
diminish overall beginning Thursday with strong breezes remaining
exclusive to the outer waters through the weekend. Significant
wave heights will build to 9-11 feet today, abate through Friday,
and build back up to 10-12 feet towards the end of the the
weekend.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM to 9 PM PDT Tuesday for SF Bay N
     of Bay Bridge.

     Small Craft Advisory from 9 AM Tuesday to 3 AM PDT Wednesday for
     Mry Bay.

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

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

     Gale Warning until 3 AM PDT Tuesday for Pt Arena to Pt Reyes 10-
     60 NM.

&&

$$

SHORT TERM...JM
LONG TERM....JM
AVIATION...Murdock
MARINE...SO

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