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Area forecast discussion 
National Weather Service San Diego California
922 am PST sun Dec 28 2014

Synopsis...
a weak ridge of high pressure aloft combined with weak surface high
pressure over the Nevada and Utah will only allow mainly high clouds
to stream over the area at times through Monday morning...with
slightly below normal temperatures today. A Gulf of Alaska storm is
expected to move through Canada...then south into our area. It will
bring unseasonably cold conditions to the region...along with
showers...a few thunderstorms...gusty winds...and unusually low snow
levels by Tuesday afternoon and extending into Wednesday. Travel
impacts should be anticipated prior to and during the new years
Holiday. Skies should clear by late Thursday into Friday under gusty
north to northwest flow. Temperatures remaining a little below
seasonal normals...especially at night.

&&

Discussion...for extreme southwestern California including Orange...
San Diego...western Riverside and southwestern San Bernardino
counties...

The weather seems to be taking a bit of a break today as the airmass
begins to warm a bit. Some high clouds are streaming over the weak
ridge...but mainly just thin clouds. Cool again tonight...but
planning on only limited patches of frost in the prone areas. The
BUFKIT soundings and local WRF indicate some increase in low level
moisture for Monday morning...but the most significant onshore push
is Monday night into Tuesday morning.

A storm originating in the Gulf of Alaska...moving moving south
through western Canada...then dropping into the western states is
expected to develop as it moves over Southern California. The GFS
ensemble puts the general location of the low over the upper deserts
Wednesday...a bit east of what the deterministic runs have shown.

There has been some issues with timing and strength of the storm.
As we get closer the models have been able to converge on a
believable solution...a very unseasonably cold...snowy one for many
areas.

The system should have all the moisture it needs to generate decent
rains across our region. Above about 2000 feet mean sea level...including the
higher portions of the inland valley areas...some areas should see
some snow. Below some passes the snow level should be locally lower
than that...with snow pellets falling below 2000 feet where
convection occurs.

With the new years Holiday...we could see some significant impacts
to travel through the region from Tuesday night through Wednesday
night. In addition...gusty winds will generate very low wind chills
in the mountains...possibly below zero wind chill values at times.
Winter weather headlines may be needed later today or by Monday for
this storm event.

Behind the storm late Thursday...cool northerly flow will persist
keeping our region in below normal temperatures. Could have some
frost and freeze activity by then. A warming trend by next Sunday
with continued dry weather trend expected.

&&

Aviation...
281630z...sct-bkn cirrus clouds at or above 200-250 with
unrestricted visible through 291000z.

West of the mts...scattered clouds at or below 2000 feet are possible after 291000z
as marine air starts to return but VFR conditions should prevail.

&&

Marine...
800 am...no marine concerns through Monday. A winter storm will
approach later Tuesday through Wednesday bringing stronger onshore
winds... showers...and a chance of thunderstorms.

&&

Skywarn...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.



&&

Sgx watches/warnings/advisories...
California...none.
Pz...none.

&&

$$

Public...small
aviation/marine...Pierce

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