Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA

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000
FXUS66 KMTR 102327
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco Bay Area
327 PM PST Mon Dec 10 2018

.SYNOPSIS...A weak front will slowly dissipate over the Bay Area
this afternoon ending any shower activity. Another weak system
may bring a few showers to our northern areas late Tuesday night
into early Wednesday. However, most areas will remain dry and cool
through Thursday. A better chance of widespread rain will develop
late in the work week and for the weekend.

&&

.DISCUSSION...as of 01:57 PM PST Monday...In the near term a cold
front continues to wash out over the Bay Area. Latest KMUX radar
imagery also indicates shower activity has all but ended. There
were a few showers over the last hour or two in the East Bay
Hills, but even those have dissipated or moved east of the
forecast area. In the wake of the dissipating cold front clouds
will continue to thin/clear with some afternoon sunshine.

Given the ample low level moisture and gradual clearing decided to
add some patchy fog tonight for the North Bay Valleys. It`s
possible some patchy fog could also develop in the East Bay
Valleys.

For Tuesday - a shortwave upper level ridge will briefly pass over
the region before another system approaches from the north.
Temperatures will be similar to today with highs in the 50s to mid
60s, which is close to normal for December.

Another weak system may bring rain into the Bay Area Tuesday into
Wednesday, but falls apart as it runs into the ridge. Models have
been trending drying over the last few days and see no reason to
change current forecast. Will continue the slight chance far
northern area of the North Bay.

High pressure returns on Wednesday and Thursday with a slight warm
up.

A decent low pressure system is still on track to move into the
Pac NW Friday and drag a cold front through CA. This system seems
a little better than today`s front, but by no means a real soaker.
The heaviest precip will be focused north of the Golden Gate and
dissipate as the front moves southward during the day Friday.

Farther down the road a wet system looks to impact the region late
next week. Surprisingly the medium/long range models are in
decent agreement with a system moving through. Taking a looks at
potential - atmospheric river guidance puts IVT values in the
moderate category. Obviously it`s still several days out, but
something to keep an eye one. Regardless, it`s nice to see that
the overall pattern will remain somewhat active during the next
seven days.

&&

.AVIATION....as of 03:27 PM PST Monday...for 00Z TAFs. Sky
conditions have mostly cleared out over the region in wake of a
weak frontal passage earlier in the day. Lingering FEW/SCT clouds
at around 5-7kft persist with VFR conditions region-wide. The
forecast becomes a bit more challenging overnight as there is the
possibility of lowing visibility and development of low clouds
over portions of the region, mainly North Bay and East Bay Valley
terminals. However, forecast confidence is low that these
conditions will develop given the drier air that has filtered into
the region this afternoon. Generally light winds are forecast to
prevail.

Vicinity of KSFO...VFR conditions likely to persist through the
evening. FEW/SCT low clouds will be possible over the terminal
early Tuesday morning, yet confidence is low for a cloud deck to
form. Winds will remain light.


SFO Bridge Approach...VFR conditions through the evening. Low
cloud development will be possible over the approach and South Bay
which may even result in MVFR or worse conditions early Tuesday
morning. Low confidence


Monterey Bay Terminals...VFR conditions forecast to prevail
through the period. Generally light onshore winds, locally
stronger at KSNS, will persist this afternoon and diminish during
the overnight. FEW/SCT clouds may develop early Tuesday morning,
yet widespread low cloud deck appears less likely. Moderate
confidence.

&&

.MARINE...as of 03:27 PM PST Monday...North to northwest winds
will develop and increase over the coastal waters through tonight
in wake of a frontal passage. Wind speeds will then diminish
briefly late Tuesday before increasing again to moderate levels on
Wednesday. A moderate northwest swell will also impact the region
through tonight before a larger swell arrives late in the week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .Tday...SCA...Pigeon Pt to Pt Pinos 0-10 nm
             SCA...Pt Arena to Pt Reyes 0-10 nm
             SCA...Pt Reyes to Pigeon Pt 0-10 nm
             SCA...Pt Arena to Pigeon Pt 10-60 nm
             SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm
             SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm
             SCA...Rough Bar Advisory for SF Bar

&&

$$

PUBLIC FORECAST: MM
AVIATION: RGass
MARINE: RGass

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