National Weather Service Forecast Discussion

Dicussion provided by the National Weather Service Forecast Office located in San Diego, California

000
FXUS66 KSGX 211225
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
425 AM PST Sun Jan 21 2018

.SYNOPSIS...
There will be areas of frost in portions of the Inland Empire
early this morning. Otherwise...high pressure aloft near the
California coast and surface high pressure over the Great Basin
will bring dry weather with a warming trend through Wednesday with
locally gusty northeast winds near the coastal foothills and
below passes and canyons at times...and some high clouds at times.
A fast moving Pacific low pressure system will move inland
through California on Thursday bringing cooling...strong gusty
west winds in the mountains and deserts...and a chance of mostly
light showers. Dry with a warming trend for Friday through next
weekend as high pressure aloft will strengthen near the West
Coast. Surface high pressure over the Great Basin will bring
periods of weak to locally moderate strength gusty northeast winds
near the coastal foothills and below passes and canyons.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

A low pressure system is centered near the four corners early this
morning with high pressure aloft over California. Surface high
pressure over the Great Basin is bringing locally gusty north to
northeast winds near the coastal foothills and below passes and
canyons with strongest gusts less than 30 mph. With clear skies
and a cool dry atmosphere...temperatures in portions of the Inland
Empire have fallen into the lower to mid 30s with areas of frost
possible through early this morning. For tonight into early
Monday...overnight temperatures should not be quite as cool as the
atmosphere begins to slowly warm and some high clouds reduce
radiational cooling some.

Warming will begin today and continue through Wednesday with high
temperatures on Wednesday 5 to 10 degrees above average for the
valleys...mountains...upper deserts...and some inland coastal
areas and a few degrees above average elsewhere. There will be
some locally gusty...mostly weak...northeast winds near the
coastal foothills and below passes and canyons at times.

For late Wednesday night and Thursday... a fast moving low
pressure system will move inland through California with some
continuing slight differences in timing among the global models.
This will bring cooling...strong gusty west to northwest winds in
the mountains...deserts...and coastal waters...and small chances
for light precipitation. This system appears to be a little drier
than the one that moved through Southern California this past
Friday and Saturday.

Then dry with a warming trend for Friday through next weekend as
high pressure aloft will strengthen near the West Coast. Surface
high pressure over the Great Basin will bring periods of weak to
locally moderate strength gusty northeast winds near the coastal
foothills and below passes and canyons.

&&

.AVIATION...
211025Z...Coast/Valleys/Mountains...Clear skies this morning with
increasing clouds AOA FL200 during the afternoon. VIS unrestricted.

&&

.MARINE...
On Thursday and Friday a Pacific storm may bring another round of
northwest winds 25 KTS or more, accompanied by rough, elevated seas.

&&

.BEACHES...
Elevated surf 4 to 6 feet with high rip current risk today...
subsiding tonight into Mon.


&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Frost Advisory until 8 AM PST this morning for San Bernardino
     and Riverside County Valleys-The Inland Empire.

PZ...NONE.

&&

$$

PUBLIC...17
AVIATION/MARINE/BEACHES...JAD

NWS SGX Office Area Forecast Discussion