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

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FXUS66 KMTR 030720

Area Forecast Discussion
National Weather Service San Francisco Bay Area
1120 PM PST Fri Dec 2 2016

.SYNOPSIS...Dry weather conditions will persist through the
weekend along with a slight warming trend in daytime temperatures.
Meanwhile, overnight conditions will remain chilly under mostly
clear skies. A region-wide cool down is forecast for the first
part of next week as a dry cold front pushes through the region.
Rain chances develop later next week.


.DISCUSSION...As of 9:05 PM PST Friday...Gusty northerly winds in
the hills have decreased since earlier today, but blustery
conditions are expected to continue locally in the hills through
Saturday morning. These northerly winds are ushering a dry airmass
into our region and evening dewpoints are as low as the mid 20s.
This dry air will allow for efficient radiational cooling
overnight and therefore chilly temps, especially in wind
sheltered valleys where overnight lows will be in the 30s.

An upper ridge centered offshore along 130W will maintain dry and
mild daytime temperatures through the weekend, with mostly clear
skies and highs mainly in the 60s. Nights will continue to be
cool, although slight moderation in overnight lows is anticipated.

A dry cold front is forecast to sweep from north to south through
our area on Sunday Night. There will not be sufficient moisture
available with this front to produce precipitation and so its
primary impact will be cooler weather starting Monday. Overnight
lows are expected to drop into the lower 30s in the cooler valleys
by Monday Night and perhaps as low as the upper 20s by Tuesday

The next chance of precipitation in our area will be during the
second half of next week. The models agree that a relatively moist
airmass with precipitable water values as high as 1.25 inches will
accompany this system. Widespread soaking rains are possible across
Northern California beginning as early as Thursday. Indications
are that the bulk of the moisture later next week will be confined
to northern California, with central California likely too see
much less.


.AVIATION...As of 11:19 PM PST Friday...VFR through the period. A
weak and dry cold front located off Oregon will reach the Bay Area
Saturday then slow in forward speed later Saturday and stall early
Sunday over the north Central Coast. This front precedes the next
cold front upstream over the Pacific expected to arrive Sunday
night and Monday. The WRF model output indicates boundary layer
humidity remains dry supporting VFR into Saturday, but N-NE winds
from the South Bay hills/mtns to the Santa Lucia Mountains may
pick up to 15-20 knots Saturday.

Vicinity of KSFO...VFR. Mainly light winds tonight and Saturday.

SFO Bridge Approach...VFR.

Monterey Bay Terminals...VFR with light offshore winds tonight and
Saturday morning. Winds temporarily light onshore Saturday afternoon
prior to becoming light offshore Saturday evening.

&& of 9:43 PM PST Friday...Building high pressure over
the northeastern Pacific will lead to gusty northerly winds along
the central coast into the weekend. The strongest winds will be
mainly over the outer waters producing hazardous conditions. A dry
cold front will slide south across the area Saturday gradually
stalling over the central coast by early Sunday morning. another
cold front will move southeastward across the area Sunday night
into Monday morning however it too will be mostly dry or dry.
Additionally, a long period swell train will arrive in the
coastal waters on Saturday.


     .Tngt...SCA...Pt Arena to Pt Reyes 0-10 nm
             SCA...Pt Arena to Pigeon Pt 10-60 nm
             SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm




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