Harbison Canyon, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

627
FXUS66 KSGX 050416
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
916 PM PDT Wed Jun 4 2025

.SYNOPSIS...
Drizzle will be possible tonight through early tomorrow morning
for portions of the coastal and inland areas of San Diego and
Orange counties, and within the IE. Drier conditions returning
tomorrow into next week, with a warming trend through the
weekend. High temperatures will peak Sunday and Monday at a few to
around 5 degrees above average for coastal areas and 5 to 10
degrees above average for the mountains and deserts. Night and
morning coastal low clouds will cover much of the valleys into
Thursday, then not spread as far into the valleys for the weekend
into early next week as the marine layer becomes shallower.

&&

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

Update: All showers and thunderstorms have now made their way out of
the CWA. There could be some drizzle for the coastal and inland
areas throughout the night. This will clear out for the inland areas
and most of the coastal areas by later in the morning tomorrow. High
pressure will be building back in over the region, although some
overall troughing will keep the onshore flow going strong throughout
the rest of the week, although further subsidence from the building
high pressure is going to allow for the marine layer to become more
thin and shallow beginning tomorrow night, and therefore will not
extend as far inland.

There will be a gradual warming trend going into the weekend.
There will be an upper level low which could help to hold down the
temperatures slightly going into the weekend. Models are still
having a hard time on the placement of this. The subtropical ridge
will be building over Mexico beginning this weekend into early
next week, which depending on where the ridge axis establishes
itself, could result in warmer temperatures early next week,
otherwise more troughing upstream advancing slowly towards the
region will result in a slight cooldown towards the mid part of
next week.

(Previous discussion submitted at 140 PM):

This afternoon...Satellite imagery shows cumulus cloud buildups
over the local mtns but radar is yet to detect any precipitation,
except over the mtns of northern Baja. There is still time for
showers/tstms to develop this afternoon/evening in our local mtns.
Any convective activity will likely dissipate around 7 pm. The
marine layer low clouds are very slow to clear and continue to
cover the coastal areas and the western portions of the San Diego
County valleys.

From previous discussion...
The atmosphere over SoCal will steadily become drier today through
tomorrow for decreasing chances of afternoon showers/tstms as
conditions become more stable.

In spite of broad troughing over the western US through Friday with
a closed upper low developing off the CA coast on Sat, temperatures
will slowly rise through the weekend. Friday high temperatures
will be mostly within a few degrees of average, ranging from
around 70 near the coast to the 80s for the Inland Empire, with
100 to 104 for the lower deserts.

As we move into the weekend, the sub-tropical high over northern Mexico
will build over AZ and extreme southeastern CA. Slow warming will
continue through the weekend with the heat peaking on Sunday and
Monday. High temperatures for Sunday will range from a few to
around 5 degrees above average for coastal areas and 5 to 10
degrees above average for the mountains and deserts. High
temperatures on Sunday will range from the lower 70s near the
coast to the mid 80s to mid 90s for the Inland Empire, with 105
to 110 for the lower deserts. The marine layer will become
shallower with night and morning coastal low clouds not spreading
as far into the valleys.

Not unexpectedly, model solutions diverge as we move into next
week so there is measurable uncertainty in the forecast details.
In general, we will see the sub-tropical ridge expand westward but
remain to our south with weak ridging over the west coast. We can
expect dry conditions to persist through the middle of next week
with a shallower marine layer modifying temperatures near the
coast. Inland temperatures will remain mostly several degrees
above average.


&&

.AVIATION...
050330Z....Coast/Valleys...Low clouds based 1500-2000 feet MSL have
pushed into most of San Diego/Orange Counties and southern IE
already. Expecting the rest of the IE to fill in overnight with
minor vis restrictions possible (3-5 SM) as bases lower slightly.
Clearing Thu morning 15-17Z for inland areas, 18-20Z for Orange
County coast, and only partial clearing for San Diego County coastal
areas 19-21Z, with KCRQ and KSAN likely remaining under cloud cover
all day once again. Low clouds push inland again after 00z Friday
with bases continuing to hover between 1000-2000 ft MSL.

Mountains/Deserts...Generally SKC with a typical diurnal wind
pattern through Thursday. ISO SHRA/TSRA based at 10000 feet MSL
possible over the San Bernardino County mountains and high desert
after 21z Thursday.

&&

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

&&

$$

UPDATE...Stewey
PUBLIC...PG
AVIATION/MARINE...KW