Alta Loma, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

083
FXUS66 KSGX 210458
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
858 PM PST Wed Nov 20 2024

.SYNOPSIS...
Warm and dry weather will continue each afternoon through Friday
with cool nights and mostly clear skies. A cooler and wetter
pattern will enter the region this weekend into early next week.
Some areas may see rainfall by Saturday, others shortly
thereafter. Snow levels will be high, so expect rain for most
mountain communities. Confidence on exact details are slowly
coming together, but still low at this time. Another round of
wetter weather may occur into early next week as well.

&&

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

No significant changes to the forecast this evening as stable high
pressure continues over the area.

Previous discussion from 1:55 pm Wednesday November 20th, 2024

.SHORT TERM (Thursday through Saturday)...
Satellite continues to show clear skies over SoCal as high
pressure dominates the Southwest. Light winds and warm weather
will continue through Friday as high pressure maintains its hold
over the Desert Southwest. NBM chances for temperatures to reach
into the lower 80s will be highest by Thursday. Chances are lower
for the San Diego valleys 10-40%, 30-60% across the Inland Empire
and 50-80% in the lower deserts.

A storm to the north currently impacting Northern California and
the Pacific Northwest will drift southward this weekend. The
atmospheric river associated with this storm will move closer to
our region by Saturday, becoming weaker per latest IVT output
values near 250-400 kg/m/s. Model trends from EPS and GEFS
continue to show drier solutions on Saturday for our area, so
confidence on the start time of any precipitation is slowly
increasing on a later start. Trimmed back larger POPs so most
areas along and west of the mountains see a 20-40% chance of
precip by Saturday evening. If any precip falls from this
weakening AR, northern areas will be favored to see the rain
earliest along with higher totals. Some leftover showers may make
it south toward San Diego County by Saturday night or Sunday
morning. Whatever occurs, confidence is high that rain totals
will be light. Snow levels will be high with this system as well,
over 8,000 feet.

&&

.LONG TERM (Sunday into middle of next week)
A series a shortwaves will rotate within the upper level trough
the weekend into early next week. One of these waves may be deep
enough to bring another chance of precipitation later on Sunday
through early Tuesday. Model ensembles continue to show widespread
differences, but if this occurs we may be able to see some heavier
rain and high elevation snow. Confidence on these details by this
time are still on the low end. My confidence is higher that we
will continue to see a troughing pattern overhead, which will be
indicative of cooler and breezier weather across the area. Long
range models diverge a bit by the middle of next week, some
showing slight warming and drying, others showing more cooler and
breezier weather. We will continue to monitor the outlook for
Thanksgiving, which may not be calm and dry.


&&

.AVIATION...210430Z...Aside from some upper level cirrus clouds,
mostly clear skies and VFR conditions prevail through Thursday
evening.

&&

.MARINE...
No hazardous marine weather conditions expected through Monday.

&&

.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...Suk
AVIATION/MARINE...Munyan