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fxus66 kmtr 270600 

Area forecast discussion
National Weather Service San Francisco Bay area
1000 PM PST sun Feb 26 2017

Synopsis...a cold front with scattered showers over northernmost
California will move southeastward over the Bay area and central
coast very late tonight and Monday morning. Many locations will
not see wet weather due to the more widely spaced weak convective
type of precipitation associated with this frontal system, but
locations that do see wet weather will generally have light amounts
perhaps upwards of a tenth of an inch. Snow showers are likely
over the higher elevations. Dry weather conditions then return for
the remainder of the work-week along with a gradual warming trend
as high pressure builds aloft.

&& of 8:35 PM PST was a picturesque day
in all locations with a chill in the air coupled with isolated to
widely scattered showers as northwesterly unstable flow continues.
The 0.39" precipitable water value on the most recent 00z Oakland
sounding was only marginally higher compared to this morning's
12z sounding; mainly dry air continues, freezing level near 4200
feet and wet bulb zero near 3500 feet. One more reinforcing push
of cold air visits Monday into Tuesday nudging 850 temperatures
downward to -2c to -4c Monday into Tuesday. For comparison,
inspection of all soundings per spc's climatology Page shows
oakland's late winter season 850 mb temperature has been colder
(-6.8c on March 2nd). Nonetheless, unseasonably cold temperatures
can be expected to close out the month. With March soon to be here
a fairly rapid return to upper level ridging will coincide with
its start and extend the mainly dry stretch a bit further down the
Road this week. Over the upcoming weekend the ridge will flatten
out possibly allowing some light wet weather from the Pacific
northwest to reach as far south as the Bay area.


Previous of 12:50 PM PST Sunday...aside from cumulus
developing over the mountains/hills this afternoon, mostly sunny
conditions prevail ahead of an approaching weather system to our
north. The latest forecast models and current trends bring a
frontal boundary across the region late this evening and through
the overnight hours with isolated to scattered showers likely.
These showers will likely impact the North Bay late this evening
or tonight and shift southward through the central coast overnight
into Monday morning. Rainfall amounts in the range of a few
hundredths of an inch to a couple tenths will be possible yet not
all locations will pick up measurable precipitation. In addition,
snow levels are forecast to lower again to the 3,000-3,500 foot
range along the central coast with below 3,000 northward. Thus,
should see some snow showers across the region with light
accumulation in the higher elevations. Meanwhile, overnight
temperatures will remain in the 30s to lower 40s as this system
will bring a reinforcing shot of cooler air across the region.

Lingering showers will be possible into Monday morning before
diminishing in coverage by the afternoon and evening. Dry weather
conditions are then likely for the remainder of the week as high
pressure builds out over the eastern Pacific. Temperatures will
also begin a gradual warming trend late in the week with
widespread 60s likely by Thursday and Friday. Overnight
temperatures will also moderate some and only cool into the upper
30s to lower 40s by late week, compared to the lower/mid 30s more
common the next few nights.

The upper level ridge is forecast to weaken a bit by the upcoming
weekend as a mid/upper level through approaches the Pacific
northwest. At this time, the best chance of precipitation will be
north of the region yet cannot rule out the system clipping the
far northern portion of the North Bay by Saturday night into
Sunday. However, not expecting widespread heavy rainfall with most
locations remaining dry across the region through the extended
forecast period.

&& of 09:55 PM PST Sunday...latest kmux radar returns
show scattered showers developing from the sf Bay region down
through Monterey, and gradually shifting southeastward. Generally
VFR through the forecast period. That said, there is the
possibility passing showers could temporarily lower ceilings down
into the MVFR range, as well as bring some wind gusts up into the
15 to 20 kt range. Showers look to taper off from the north
overnight and Monday morning.

Vicinity of ksfo...VFR except possibly briefly down to MVFR
during a shower. West to southwest winds less than 10 kt but can't
rule out a possible gust into the 15 to 20 kt range with a
passing shower. Moderate confidence. Dry VFR conditions expected
to prevail during the day on Monday.

Sfo bridge approach...similar to sfo.

Monterey Bay terminals...VFR except possibly briefly down to MVFR
during a shower. Winds less than 10 kt but can't rule out a
possible gust to around 15 kt with a passing shower. Moderate
confidence. Dry VFR conditions expected to prevail by late morning
on Monday.

&& of 08:54 PM PST Sunday...some scattered showers are
likely over the coastal waters tonight and Monday as a weak
frontal system moves through from the north. No significant swell
trains are expected through the end of the forecast period, and
winds are projected to remain below gale force levels.


Mtr watches/warnings/advisories...
... Arena to Pigeon pt 10-60 nm from 4 am



Public forecast: canepa/rgass
aviation: blier
marine: blier

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