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Area forecast discussion 
National Weather Service San Diego California
400 am PST Friday Dec 26 2014

Synopsis...
periods of gusty northeast winds will continue along the coastal
slopes of the mountains and adjacent foothills areas through
Saturday morning. Continued below average temperatures through the
weekend with areas of late night through early morning frost in
portions of the valleys and deserts into Sunday morning. Weaker
winds with continued below average temperatures for Sunday and
Monday. For Tuesday through Thursday of next week...a cold low
pressure system from the north could bring periods of precipitation
and gusty winds with well below average temperatures.

&&

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

Short term (today through sunday)...
gusty northeast winds will continue at times along the coastal
mountain slopes and adjacent foothill areas in Orange and
southwestern San Bernardino counties into Saturday morning...and
expand into the coastal mountain slopes and adjacent valleys in
Riverside and San Diego counties for late tonight through Saturday
morning with occasional gusts to 50 miles per hour.

With a cold dry atmosphere in place...there will be areas of late
night through early morning frost in portions of the valleys and
deserts into Sunday morning. At present...the coldest temperatures
are expected for Saturday night.

&&

Long term (monday through wednesday)...
continued cool for Monday. For Tuesday through Thursday of next
week...a cold low pressure system from the north has the potential
to bring significant impacts to Southern California. However...there
remain significant differences in the timing and placement of
potential impacts. At a minimum...there should be periods of well
below average temperatures and periods of precipitation. There is
also the potential for very low snow levels at times...below 3000
feet...and periods of strong gusty winds. In the current model
cycle...the GFS is about a day faster and the European model (ecmwf) a day slower.
This is a reversal from model runs 24 hours Aga in which the European model (ecmwf)
was faster and the GFS slower. The latest Gem is in between. All are
within a reasonable range of the possibilities.

Until those timing and placement issues are resolved...the current
forecast maintains below average temperatures and mostly slight
chance to chance probability of precipitation for the Tuesday through Thursday period with
timing skewed more toward the European model (ecmwf) ensemble mean...especially with
regard to the winds which are most significantly impacted by timing
and placement issues.

Most likely when those timing and placement issues are resolved...
there will be periods in the Tuesday through Thursday time frame
where temperatures will be lowered...snow levels lowered...probability of precipitation
increased...and winds strengthened.

&&

Aviation...
261130z...clear skies with unrestricted visible will prevail through Friday
night. Periods of NE surface winds with local surface gusts 30-40kt
through Sat morning...mainly in and below the Santa Ana Mountain
canyons...inland Empire...and eastern Coachella Valley. These winds
may reach vicinity ksna...kont...ksbd...kral...kcno...kpsp with low level wind shear at
times. Strong up/downdrafts are possible in mountain wave activity
on the coastal side of the mountains and near the passes.

&&

Marine...
330 am...buoy 46806 still indicating peak north wind gusts to 21 knots
at 0850z. In addition...models indicate offshore areas below the
Santa Ana Mountain canyons off of northern San Diego County will
experience NE winds of 25 kts or more this morning. So a Small Craft
Advisory remains in effect through at least 8 am this morning due to
these winds and choppy seas.
&&

Beaches...
330 am...a long-period west-northwest will continue elevated surf of
3-5 feet...with local sets to 6 feet...and strong rip currents at
area beaches today. Swell and surf will subside over the weekend.

&&

Fire weather...
gusty northeast winds will continue at times along the coastal
mountain slopes and adjacent foothill areas in Orange and
southwestern San Bernardino counties into Saturday morning...and
expand into the coastal mountain slopes and adjacent valleys in
Riverside and San Diego counties for late tonight through Saturday
morning with occasional gusts to 50 miles per hour. A cool atmosphere will
remain in place with lowest daytime humidities around 15 percent...
mainly in portions of the valleys and inland Orange County.

&&

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

&&

Sgx watches/warnings/advisories...
California...Wind Advisory until noon PST Saturday for the Orange County
coastal areas...San Bernardino County mountains...San
Bernardino and Riverside County valleys-the inland Empire...
Santa Ana Mountains and foothills.

Frost advisory until 8 am PST this morning for the San
Bernardino and Riverside County valleys-the inland Empire...
San Diego County valleys.

Frost advisory from 9 PM this evening to 9 am PST Saturday for
the San Bernardino and Riverside County valleys-the inland
Empire...San Diego County valleys.

Frost advisory from 3 am to 7 am PST Saturday for the San Diego
County deserts.

Frost advisory from midnight Saturday night to 8 am PST Sunday
for the San Diego County deserts.

Frost advisory from midnight Saturday night to 8 am PST Sunday
for the Coachella Valley.

Frost advisory from midnight tonight to 8 am PST Saturday for
the San Diego County coastal areas.

Wind Advisory from 4 am to noon PST Saturday for the San Diego
County mountains...San Diego County valleys.

Pz...Small Craft Advisory for winds until 8 am PST this morning for
the coastal waters from San Mateo Point to the Mexican
border and out 30 nm...waters from San Mateo Point to the
Mexican border extending 30 to 60 nm out including San
Clemente Island.

&&

$$

Public/fire weather...17
aviation/marine...jad

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