Weather Service Report

FXUS66 KMTR 281212

Area Forecast Discussion
National Weather Service San Francisco Bay Area
512 AM PDT Fri Oct 28 2016

.SYNOPSIS...Wet and unsettled conditions will persist through the
upcoming weekend as a series of storm systems impact the region.
Temperatures will remain near or slightly below seasonal averages
through the forecast period. 

&& of 03:32 AM PDT Friday...Widespread
precipitation continues across the region this morning as an
upper level low remains about 200 miles to the west-southwest of
the Monterey Peninsula. Rainfall rates generally remain light but
have been as high as 1/2" or so per hour at times within heavier
showers. Overall, precipitation amounts have been much less than
previously thought and rain rates are also not as impressive.
Thus, have cancelled the Flash Flood Watch for the Soberanes and
Chimney Fire burn scar areas given the lessening threat for high
rainfall rates that would result in debris flows. With that said,
widespread precipitation will continue through the morning hours
as the upper level low lifts northeast toward the San Francisco
Bay Area. While the best chance for thunderstorms remains to our
south, cannot rule out the possibility of a few thunderstorms
developing over the Central Coast as the upper level low nears the
coast this morning. Widespread precipitation will tapper off to
lingering showers by this afternoon as the main mid/upper level
system pushes inland.

Given the unsettled pattern, can expect lingering showers to
persist into Saturday, yet widespread rainfall is not expected.
Our next weather system will approach from the west/northwest late
Saturday night into Sunday morning as a mid/upper level through
approaches the Pacific Northwest. This will bring another around
of widespread precipitation to the region, likely beginning over
the North Bay Saturday night and spreading south and inland
through Sunday morning. Lingering showers will again be possible
Sunday night into Monday in wake of the passing frontal boundary.
As another mid/upper level trough approaches the Pacific Northwest
and northern California Monday night into Tuesday, another round
of precipitation is expected across the region. However, the
forecast models are not showing much precipitation with this third
system as it rapidly pushes inland to our north.

Mostly dry conditions return to the much of the region by midweek
as short-wave ridging builds in aloft. Meanwhile, cannot rule out
a slight chance of precipitation over the northern portion of the
region late in the week as forecast models show a few weak systems
pushing inland to our north. With the persistent unsettled patter,
expect mostly cloudy conditions to continue along with daytime
temperatures below seasonal averages.

&& of 4:59 PM PDT Thursday...For 12z TAFs. Rain
will persist across the region through this morning then gradually
taper through the afternoon. Ceiling heights and visibilities will
be up and down all day with cigs jumping between MVFR to IFR.
Light and variable winds expected to continue through this morning
with light westerly winds returning to the area this afternoon. 

Moderate confidence. 

Vicinity of KSFO...Periods of rain will continue through this
morning with cigs and vsbys jumping between MVFR to IFR. Winds
will remain light and variable through through morning becoming
light and westerly this afternoon. 

SFO Bridge Approach...Similar to KSFO. 

Monterey Bay Terminals...Periods of light to locally moderate
rain will continue through this morning with cigs and vsbys
jumping between MVFR to IFR. Winds will remain light and variable
through through morning becoming westerly this afternoon.

&& of 2:48 AM PDT Friday...Light to moderate showers
will continue across the coastal waters as a low pressure system
approaches from the southwest. this system will bring northwest
winds to the area this morning with winds switching back to the
south tonight. light winds and seas will persist through much of
the period. the next in a series of storms will arrive from the
northwest on saturday morning. rain develops saturday night into
sunday with a return of gusty west to southwest winds by sunday
afternoon ahead of yet another cold front...along with rapidly
building seas.





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