Area Forecast Discussion
Issued by NWS Sacramento, CA

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FXUS66 KSTO 251702

902 AM PST Tue Nov 25 2014

Dry and mild weather is expected through Thanksgiving as high
pressure covers the region. Rain is expected to return to the
region by late Friday and continue into early next week. Snow
across the mountains is likely to cause travel difficulties for
the holiday weekend.


Strengthening upper level ridging is bringing a warmer start to
the day today, with limited amounts of fog and mist quickly
burning off. Plan to increase forecast high temperatures for this
afternoon a few degrees with mostly clear skies and a warming
airmass. Forecast looks good otherwise.

A weak wave will bring some precipitation gradually spreading
into the area from north to south late Friday. This should have
little impact on travel. More substantial moisture arrives on
Saturday, with the main storm system moving in on Sunday and
continuing into Monday. At this point, it looks like accumulating
snow could begin early Saturday, with more significant amounts late
Saturday through Sunday and Monday. Some lingering moisture
should persist into Tuesday, with drier weather returning ny
Wednesday. EK

.Previous Discussion...
Amplifying upper ridge over the eastern Pacific is pushing most of
the high clouds well to the north of the area this morning.
Despite the mainly clear skies and light winds, temperatures are
a little warmer at most locales compared to 24 hours ago.

The high pressure ridge will strengthen across NorCal through
Wednesday allowing temperatures to warm a little each day. Some
high clouds are expected to drift through the region the next
several days. Patches of fog, mainly from near Marysville south,
are expected the next couple of mornings, but overall the
northerly dry flow should help to limit the extent of fog each
morning. Thanksgiving continues to look dry and mild this year.

Warm advection and slowly approaching frontal system may spread
some light precipitation across the northern half of the forecast
area by later Friday, but more significant precipitation and
weather impacts are expected to hold off until the weekend.


.Extended Discussion (Saturday through Tuesday)

Medium-range models continue to be in good agreement, swinging the
first in a series of cold fronts through Northern California late
Friday into Friday night. Unsettled weather will likely continue
into early next week with strong jet dynamics and good diffluent
flow aloft. The strongest precipitation is likely to be Sunday
into Monday as the cold upper low approaches the region. The
primary impacts anticipated will be to Thanksgiving holiday travel
with rain, snow, and breezy conditions. Subtle differences in the
systems` timing, position, and strength can have a large impact on
amounts. Being this far out, the rain/snow forecast amounts will
likely change. Nonetheless, be prepared for potentially delayed
travel due to road conditions. In addition, fallen leaves this
time of year can contribute to clogged drains and localized




VFR conditions and light winds for the period as high pressure
remains in control. Valley fog did not materialize this morning as
models had forecasted with only an hour of MVFR visby at KSCK and
KSMF. Have left it out of TAFs for Weds morning at this time with
stagnant air mass and limited moisture. Something to watch for
later forecasts. CEO


.STO Watches/Warnings/Advisories...

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