Alberhill, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

953
FXUS66 KSGX 220546
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
946 PM PST Fri Feb 21 2025

.SYNOPSIS...
Patchy low clouds and fog along the coast with breezy northeast
winds through the passes overnight. Warm weather with highs 10-20
degrees above normal will continue through the middle of next
week, warmest Tuesday and Wednesday as another round of weak to
moderate Santa Ana winds develops. An area of low pressure is
expected to move closer to SoCal by later next week, bringing
cooler weather with an increased chance of precipitation.

&&

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

Patchy low clouds continue along portions of the northern San
Diego County and souther Orange County coasts this evening, but
are high enough to mitigate any dense fog concerns for now. The
00Z KNKX sounding shows the marine inversion based near 1300 ft
MSL, but this is expected to come down some overnight as the upper
level ridge moves overhead. Weak offshore flow will continue
overnight, limiting the inland extent of what low clouds there
are. Otherwise locally north to northeast wind gusts 20-30 mph
below the passes and canyons overnight, weakening Saturday
morning.

Weak upper level ridging will remain in place through Monday,
maintaining warm and dry weather. Highs each day will be around
10-15 degrees above normal inland, and around 5-8 degrees above
normal at the coast. Little marine layer cloud cover is expected
during this period, but if any do develop, there would be a risk
of dense fog along the coast. Otherwise light winds and mostly
sunny skies during this period.

An upper level short wave then traverses the Pac NW and digs into
the eastern Great Basin and Northern Rockies, with surface high
pressure developing in its wake. While there are some
differences amongst the ensembles with the details of this wave,
they result in only minimal differences in the temperature and
wind forecasts here. Santa Ana winds will likely (60% chance)
develop by Tuesday, becoming weak to moderate on Wednesday as
pressure gradients peak. Given that this is solely a gradient-
driven event, expect winds to remain confined to the usual
passes/canyons and foothills. The Santa Ana winds combined with an
amplifying ridge of high pressure over the Western US will
generate additional warming, especially for areas west of the
mountains, Tuesday and Wednesday when highs in the foothills and
inland valleys will be as much as 20 degrees above normal -
nearing 90 degrees! Highs in the low deserts be in the low 90s
these days as well.

Beyond Wednesday things become a bit less certain as a pesky
closed low begins to enter the picture. For Thursday, around 55%
of the ensemble members have the low already moving into the
California coast, which would bring much more cooling than the
remaining 45% which keeps the low further west and maintains some
ridging over the area. This continues into Friday with the low
placement ranging anywhere from off Point Conception to the Four
Corners region. Some small (10-15%) chances of precipitation enter
the forecast by Friday, but even so any moisture associated with
this low is very limited, and there is a chance that it could
track far enough south that we miss out entirely.

&&

.AVIATION...
220500Z... Coast...Areas of low clouds/fog will continue to expand
within 10 miles of the coast overnight, though timing of CIGs will
be low confidence at airports. BKN/OVC CIGs will be 700-1000 ft MSL
through 09Z Sat but then will lower to 300-700 ft MSL. Areas of fog
will produce VIS 0-2 miles mainly over higher coastal terrain where
terrain obscurations are likely, but VIS of 0-2 miles could locally
reach sea level. There is a 25 percent chance VIS will below 1 mile
or less at SAN, a 40 percent chance at SNA and 70 percent chance at
CRQ during some time period between 09Z and 16Z Sat. Most areas
should clear 14Z-17Z Sat with local BKN CIGs or reduced VIS at the
beaches Sat afternoon. Confidence is low on low cloud/fog
development Sat evening, but if it develops it will be near the
immediate coast.

Valleys/Mountains/Deserts...Local north-northeast winds with gusts
20-30 kt will continue through 18Z Sat, mainly in the foothills
including below Cajon Pass. Otherwise, mostly clear skies with
unrestricted VIS will prevail through Sat evening.

&&

.MARINE...
No hazardous marine conditions are expected through Wednesday.

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.

&&

$$

PUBLIC...SS
AVIATION/MARINE...Maxwell