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fxus66 kmtr 221526 
afdmtr

Area forecast discussion
National Weather Service San Francisco Bay area
726 am PST Wed Nov 22 2017

Synopsis...high pressure will continue to produce dry and warm
weather across our entire region through Wednesday. Rain chances
return to the North Bay on Thanksgiving, but the rest of the
region is expected to remain dry with continued warmer than normal
temperatures. Dry weather is expected to return to all areas on
Friday. High pressure will move east during the weekend and rain
chances will begin in the north on Saturday and spread across most
of the rest of the region by Sunday night.

&&

Discussion...as of 7:20 am PST Wednesday...fog continues to be
reported across portions of our County Warning Area this morning, although dense
fog appears to be less prevalent over the past hour. The dense fog
advisory currently in effect will be allowed to expire at 8 am.

Another round of well above normal temperatures can be expected
today with a ridge of high pressure in place combined with
offshore flow and warm 850 mb readings. Could see a few records
highs especially for locations south of San Francisco Bay.
Portions of Monterey and San Benito counties will soar into the
80s.

Dry weather remains on track through Saturday for most of our
region. Just a chance of light rain generally north of San
Francisco on Thanksgiving day. Possible return to a wetter pattern
for next week. The ensembles have been hinting at that. Will be
interesting to see if the operational runs follow suit.

Previous discussion...a light offshore wind has brought areas of
Tule fog to the north and East Bay valleys this morning.
Visibilities may locally drop to as low as 1/4 mile before fog
Burns off mid- morning.

Upper level high over Southern California will bring another warm
day to the region today. As was the case yesterday...the warmest
temperatures will be south of the sfo Bay area with highs in the mid
70s to mid 80s. Record high temperatures are possible in these areas
again.

The ridge will flatten on Thursday as an upper level trough moves
into the Pacific northwest. This trough splits off with only the
northern part of the trough moving towards the coast and the
southern portion nearly forms a cutoff low near 35/140w. As a result
of this split just about all of the rain will remain north of the
district. The majority of the models being light rain to northern
Sonoma County Thursday afternoon while the GFS is an outlier
bringing rain chances a little further south into most of the North
Bay and even San Francisco. The forecast GOES along with the model
majority. Any rainfall amounts should be under one- tenth of an
inch.

Dry weather returns Friday as the trough moves inland. In the
meantime the upper ridge will move east and the next upper level
trough will be deepening along 140w. This trough will kick the
cutoff low northeast bringing a chance of rain to the North Bay on
Saturday. Rain spreads south over the rest of the district Sunday as
the trough moves through. Lingering showers will persist into Sunday
night mainly from the sfo Bay area north. Dry weather return early
next week as ridging returns to the area.
&&

Aviation...as of 03:30 am PST Wednesday...for 12z tafs. Currently
VFR with patchy fog settled into the North Bay. Ksts is still
reporting 1/4 mile visibility. Klvk, kapc, and kccr are also still
reporting MVFR visibility with mist. Expecting these conditions
to last through morning. Elsewhere, high clouds continue to pass
over the region, and cigs may turn broken late this morning or early
this afternoon but will remain VFR.

Vicinity of ksfo...VFR with calm winds. Light winds will continue
into the day with winds becoming west-northwest late this morning or early
this afternoon. Moderate to high confidence.

Sfo bridge approach...similar to ksfo.

Monterey Bay terminals...VFR. Winds east-southeast tonight and into the
morning, becoming onshore 5-10 knots in the afternoon. Moderate
to high confidence.

&&

Climate...

Here is a list of record high temperatures
along with the most recent date it occurred.
*Signifies there are additional years the record was set.

Tuesdaywednesday

Sf Bay area
location................
Healdsburg..............79/1959
Santa Rosa..............78/1939
Calistoga...............90/1932
Kentfield...............77/1939
San Rafael..............80/1959
Napa....................81/1959
San Francisco...........76/2005
sfo Airport.............74/1959
Oakland Airport.........77/1959
Richmond................74/2002
Livermore...............80/1915
Moffett field...........75/1959
San Jose................75/1924
Gilroy..................79/2005

Monterey Bay area
location................
Monterey................80/1954
Santa Cruz..............84/1933
Salinas.................78/2015
Salinas Airport.........86/1933
King City...............92/1930

&&

Marine...as of 02:22 am PST Wednesday...generally light to
moderate winds will continue as high pressure remains over the
coastal waters. Rain chances will return for the northern waters
towards the end of the week and over the weekend. Winds and swells
will increase over the weekend.

&&

Mtr watches/warnings/advisories...
... Fog advisory until 8 am...caz506-510

&&

$$

Public forecast: Bell/west pi
aviation: as
marine: as
climate: mm

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