Westminster, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

556
FXUS66 KSGX 260356
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
856 PM PDT Wed Jun 25 2025

.SYNOPSIS...
A gradual warming trend will continue through the end of the week.
The peak of the heat is expected early next week. The marine layer
will bring night and morning low clouds to coastal areas through the
rest of the week. The marine layer is expected to become shallower,
with less low cloud coverage in the valleys by the end of the
week.

&&

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

Update: The marine layer continues to grab onto some of the coastal
areas this evening, and this will slowly begin to fill into the
inland areas by later in the night. It will be slightly later into
the night before it begins to creep into the IE. This should begin
to scatter out from east to west shortly after sunrise tomorrow
morning. The marine layer will continue to become more thinned out
with lower bases and less coverage going into the weekend. Models
have been overall consistent, except that there has been a slight
shift in the ridge axis by early next week to be slightly more to
the east, with a trough deepening just off the coast of
California, which will slowly propagate towards the region and
allow for a slight cooldown towards the middle of next week. There
will also be some southerly flow with increased moisture that may
help keep temperatures slightly cooler for the early part of next
week, especially for the deserts, otherwise, it continues to look
like Monday and Tuesday will be the hottest days for the next
week.

(Previous discussion submitted at 120 PM):

Visible satellite at 1 PM was showing clear skies across the area.
Temperatures at 1 PM were running 5 to 10 degrees warmer than this
time yesterday for inland areas and a few degrees warmer than
yesterday at the coast. The marine layer is expected to decrease
to 1500-2000 ft in depth Thursday into early next week. This will
limit the inland extent of night and morning low cloud coverage
to the coast and western valleys.

For the end of this week into early next week, an area of high
pressure from south of the border will build near the Four Corners
region. Temperatures on Sunday are trending slightly cooler than
the past few days with chances of exceeding 110 degrees down to 40
to 70 percent. Chances of the low deserts exceeding 110 degrees
are now highest on Monday and Tuesday at 60 to 80 percent. GFS
ensemble precipitable water guidance is indicating that the
position of the high pressure would allow for a moisture surge
from the south/southeast into the low deserts over the weekend or
early next week. The ECMWF ensemble guidance is notably drier. If
the solutions with an increase in precipitable water come to
fruition, that would keep high temperature readings on the lower
side of guidance. If it remains on the drier side of guidance, the
hotter solutions will occur with higher likelihood of
temperatures reaching or exceeding 110 degrees.

Conditions are also expected to warm up west of the mountains, but
an upper level weak trough lingering off the coast of Southern
California is expected to keep the aforementioned high pressure from
moving too far west. Chances of the Inland Empire exceeding 100
degrees are now highest Monday through Wednesday and still mostly 20
to 30 percent, locally up to 50 percent in the eastern portion of
the Inland Empire. For the eastern San Diego valleys, chances for
temperatures to exceed 90 degrees are 30 to 50 percent, locally up
to 60 percent in the far eastern valleys. Chances of inland Orange
County exceeding 90 degrees on Sunday and Monday are closer to 10 to
20 percent.

&&

.AVIATION...
260300....Coast/Valleys...Low clouds based 1300-1700 ft MSL have
developed along the SD County coastline. Will slowly spread up to 20
miles inland by 13Z Thu, with patchy clouds and fog in the
western/southern IE. CIG impacts likely at coastal TAF sites 03Z-18Z
Thu. 50-60% chance of a CIG at KONT 11Z-16Z Thu and less chances at
KSBD. Minor vis restrictions (3-5SM) and IFR CIGs where clouds form
over elevated inland areas including the IE. Low clouds scatter to
the coast 16-18z Thursday. 40-50% chance CIGs remain BKN through the
afternoon for SD beaches and nearshore waters. Clouds based 1000-
1500 ft MSL slowly push into coastal land areas after 03z Friday.

.Mountains/Deserts...Clear skies with unrestricted VIS through
Thursday evening.

&&

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

&&

.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...CO
AVIATION/MARINE...KW