Highgrove, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

107
FXUS66 KSGX 160342
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
842 PM PDT Tue Apr 15 2025

.SYNOPSIS...
A troughing pattern will continue through Friday, with cooler,
windier and wetter weather. The deep marine layer today will
maintain its presence as well, leading to cloudier skies from the
foothills to the coast. More substantial chances for light rain
showers and high elevation snow will move into the picture
Thursday and Friday. With the exception of the lower deserts, most
areas will see isolated light showers with a storm or two
possible by Friday across northern areas. The weekend into early
next week will feature warmer and brighter conditions.

&&

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

This evening...The afternoon sounding shows a deepening marine
layer in response to height falls as a low pressure system approaches
from the west. As an extensive shield of mid and high clouds
moves in, the low clouds are mostly confined to the foothills and
coastal slopes. High-resolution models continue to show the low
clouds increasing in coverage and filling in the areas west of the
mountains by early Wednesday morning. Similar to this morning,
patchy drizzle can be expected on Wednesday morning for areas west
of the mountains.

From previous discussion...
The area of low pressure off the coast will continue to move
closer for Wednesday night into Thursday. Hi-res model guidance
shows isolated light showers along and west of the mountains by
late Wednesday, with rates mainly below one tenth of an inch per
hour. This system has decent lower level moisture but is drier
above 700 mb, indicating that light showers may develop with
around a 10-20% chance of measurable precipitation. As the low
moves over the region on Thursday, chances increase slightly, with
highest chances along the coastal mountain slopes near 40%.
Expect cool weather to take hold for these two days as well, with
60s west of the mountains and highs lowering into the 70s for the
lower deserts. Mountain communities will be colder as well, with
highs struggling to reach 50 degrees. This system will bring windy
conditions to the mountains and deserts as well. Most of these
areas will see wind gusts 30-40 MPH with local gusts in passes
near 50 MPH, locally near 60 MPH in the Banning Pass.

A deep closed low will plunge southward across the Intermountain
West on Thursday, moving into the Desert Southwest by Friday. A
vorticity maxima eclipses the region during this time, increasing
chances for convection across northern areas. National Blend of
Models shows chances for thunderstorms around 10-15%. Other areas
have a low to moderate chance in seeing light showers off and on
throughout the day with continued cooler weather and a deep marine
layer. Models continue to agree on the active weather pushing out
for the weekend as zonal flow takes over. This will bring less
wind, clouds, and warmer weather to the area by this weekend and
early next week.

&&

.AVIATION...
160330Z....Coasts/Valleys...Today`s clouds have finally cleared
earlier this evening, though some have stuck around along the
coastal slopes. Similarly to last night, clouds should redevelop and
spread across the inland valleys and coastal basin over the next
several hours, with CIGs expected by 06-08z. When they form, cloud
bases will generally range from 2500-3000ft MSL. -DZ is expected
once again after 09-12z, primarily for the coastal basin, leading to
localized VIS reductions to 4-6 SM. CIGs likely to lower to 2000-
2500ft MSL with the -DZ. Given the prevalence of today`s clouds and
a strong inversion atop the marine layer, confidence in timing of
clouds clearing Wednesday is low, but would likely not occur until
after 18z, if at all. Still, cloud bases are expected to lift to
3000-4000ft between 12-18z Wednesday, so conditions will be VFR
whether the clouds clear or not.

.Mountains/Deserts... Light winds with typical westerly flow through
the mountain passes overnight. Stronger west winds develop in the
vicinity of the mountains Wednesday afternoon and evening.

&&

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

&&

.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...PG
AVIATION/MARINE...Munyan