901
FXUS66 KMTR 092111
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
111 PM PST Sat Nov 9 2024

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

.SYNOPSIS...
Issued at 1253 AM PST Sat Nov 9 2024

Active pattern continues with a shift towards cooler temps and
increased moisture. Decent rain chances across the region by early
next week, and potentially later in the week as well.

&&

.SHORT TERM...
(This evening through Sunday)
Issued at 109 PM PST Sat Nov 9 2024

Cloud cover continues to build ahead of the next rain maker arriving
in the late weekend. But between now and then, calm weather
continues. Expect partly cloudy skies to turn mostly cloudy this
afternoon with still relatively dry conditions. Overnight, expect
building coastal fog along with pockets of drizzle as the warm
sector ahead of the next cold front builds into the area. Sunday
will have lingering pockets of drizzle and mostly cloudy conditions
with the front arriving from the north that night.

&&

.LONG TERM...
(Sunday night through next Friday)
Issued at 109 PM PST Sat Nov 9 2024

The forecasting team discussed the potential of the cold front
slowing as it begins to interact with the California coast, which is
common for these systems. As such, some polishing was added to the
time of arrival of the initial rains, but otherwise the forecast
remains on track. Rain chances arrive Sunday night and spread
southward into Monday with the main band of the cold front passing
over the SF Bay 10 am to possibly noon on Monday. This line of rain
will offer the more moderate rain rates, and breezier winds. The
front move southeast through the rest of the afternoon, and only
light showers linger into Monday night.

Cold and dry air moves into the area behind the front leading to
Tuesday and Wednesday mornings having some concerns for interior
lows dipping into the 30s. Otherwise, mostly calm conditions are
expected in the mid week.

Models and blends are struggling with the time of arrival of the
next rain system, but do agree that the one-two-punch will of a cold
front and parent low passing through the Bay Area will lead to
prolonged chances for rain. As of the current forecast: the pre-
frontal drizzle arrives Wednesday evening, then the front that
night, followed by lingering showers through Thursday, and then rain
from the low pressure circulating through the region late Thursday
and lasting through much of the weekend. While rain chances look
strong, rainfall rates and amounts don`t look to be of much of
concern with overall rain totals below an inch for the rainiest
spots over the Wed-Saturday period and much lower the areas farther
south.

In the long-long term, the conveyor belt of rain systems looks to
continue with models hinting at another cold front arriving just as
the previous low pressure exits on the 17th. Model agreement is
fairly impressive considering how far out this is in the current
run, but much can still change between now and then. Be sure to keep
checking in!

&&

.AVIATION...
(18Z TAFS)
Issued at 925 AM PST Sat Nov 9 2024

Currently VFR region wide with a few/sct passing high clouds. Look
for IFR/LIFR conditions to potentially return to the North Bay and
coastal areas Sunday morning.

Vicinity of SFO...VFR. Light and variable wind becoming west near 10
knots during the afternoon, diminishing to near 5 knots tonight and
Sunday morning. Less potential for MVFR/IFR conditions Sunday
morning.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR. Increased onshore winds this afternoon
diminishing late. Greater potential for IFR/LIFR conditions Sunday
morning.

&&

.MARINE...
(Today through Thursday)
Issued at 925 AM PST Sat Nov 9 2024

A cold front approaches and moves across the coastal waters and
bays on Veterans Day. The front will result in a band of light
rain, then a wind shift over to drier northwesterly winds.
Another frontal system with rain approaches the Bay Area during
the middle of next week. Wave heights also gradually build
through the middle of the upcoming week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&

$$

SHORT TERM...Murdock
LONG TERM....Murdock
AVIATION...RGass
MARINE...RGass

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