Alta Loma, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

570
FXUS66 KSGX 062051
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
151 PM PDT Fri Jun 6 2025

.SYNOPSIS...
A deep marine layer persists for coastal and inland areas through
Saturday, with a shallower marine layer and valley/inland fog Sunday
through much of next week. Temperatures warm through the weekend,
peaking Monday and Tuesday, before a slow cooldown into the end of
the week.

&&

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

Drizzle has generally ended across the region with the deep marine
layer having burned off for most inland areas. Little change in the
heights into tomorrow supports another deep marine layer tonight
with fair low to mid level moisture, and drizzle will once again be
possible everywhere from the coast through the inland valleys. This
looks to be the last morning for noticeable drizzle in the coming
week as drier and warmer weather set in, and a more shallow marine
layer prevails through mid next week.

Currently, water vapor satellite imagery shows an upper level low
being pinched off by the ridge over the PacNW, and this low is
poised to hang off the central coast of California through Sunday.
As such, the thermal ridge axis this weekend will run from
Washington down through Nevada and into Arizona, with 850mb temps
over coastal and inland areas Monday and Tuesday around 22-24C while
deserts will see 850 temps 25-27C. This indicates surface highs may
push well above 105F for the Coachella Valley and San Diego deserts
by Monday, currently looking to peak on Tuesday with highs
potentially at or near 108-110F. Elsewhere, temperatures will be
above-normal, especially for inland areas, with 92-96F for the
Inland Empire early next week. The ridge shifts eastward Wednesday,
but zonal flow aloft sets in, limiting the cooldown for the end of
the week. At the same time, multiple shortwaves pass across northern
California and Oregon through the end of the week, not expected to
do much in the way of precipitation but a slight uptick in wind is
possible for the far northern areas, especially the High Desert.

A deep low moves down from Alaska on Thursday, with troughing
setting in over the area early Friday and into the weekend. High
temperatures will continue to fall and the marine layer deepens,
returning the region to at or below normal temperatures likely by
Friday. Long-range models are pretty aligned with the low persisting
along the Canadian coastline, with cooler weather potentially
prevailing through mid June. Welcome back to June Gloom!

&&

.AVIATION...
062130Z....Coast/Valleys...Low clouds based 1500-2500 ft MSL with
tops to 2500-3500 ft remain in place over the coast and valleys of
San Diego County. Low clouds based 1000-2000 ft MSL quickly move
back into Orange County 01-04z this evening then fill back into the
Inland Empire 06-09z. There is a 30% chance that the IE does not
fill in completely due to a slight lowering of the cloud layer.
After 10z Sat, there is a 40% chance for -DZ and BR across the
coastal basin. Local VIS reductions down to 3-5SM possible in BR.
Clearing will occur quickly in the Inland Empire and Orange County
between 14-17z Sat morning and remain in San Diego County through
the afternoon.

Mountains/Deserts...FEW-SCT cumulus based at 10,000ft MSL across the
high desert and mountains. Otherwise, clear through Saturday.

&&

.MARINE...
No hazardous marine conditions are expected today through Tuesday.

&&

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

&&

$$

PUBLIC...Zuber
AVIATION/MARINE...Westerink