Sylmar, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

971
FXUS66 KLOX 290414
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
914 PM PDT Sun Jun 28 2026

.SYNOPSIS...28/745 PM.

Night through morning low clouds will prevail through most of
this week, with temperatures well below normal through at least
Thursday. Modest warming is likely to follow. Drizzle will be
possible each night, especially near the foothills. Gusty winds
will continue over the interior mountains and deserts, as well as
southwest Santa Barbara County through at least early next week.

&&

.SHORT TERM (SUN-WED)...28/810 PM.

***UPDATE***

The short term forecast issues continue to be gusty winds, cooler
than normal temperatures, and extensive night to morning low
clouds cover. A Wind Advisory is now in effect for the Antelope
Valley (SW winds) and western Foothills, and for SW Santa Barbara
County (NW winds) where gusts up to 45 mph are likely. While
confidence in this forecast is moderate due to weaker gradients,
winds are increasing in the areas under the Advisory this evening
and believe they will not have too much trouble reaching criteria
within the next few hours. Onshore gradients between LAX to
Daggett are forecast by the NAM12 to increase the next few days,
so the gusty winds near or above Advisory levels are likely to
continue into at least mid-week.

Heights aloft will lower through Tuesday, with below normal
temperatures expected to persist through Thursday. High
temperatures tomorrow are expected to be in the 70s and 80s,
except for some 60s near the coasts. Interior temperatures will
be 10 to 15 degrees below normal during this time.

The extensive low clouds will continue to move inland each night,
at times reaching the interior valleys and with periods of drizzle
possible. The best chances of drizzle will be across the foothills
of the San Gabriels, but any lower mountain or foothill locations
could see occasional light drizzle.

***From Previous Discussion***

The upper trough situated over the Great Basin is expected to lift
northeast into Monday. In tandem, a shortwave trough will dive due
south along the British Columbia coast deepening some into Socal.
The upper pattern will slow down with weak troughing continuing
across the west into Thursday.

Evening NW winds across SW SB county will continue Monday into
Tuesday (Sub-advisory). Better chance for advisory Wed & Thurs,
but marginal if it materializes. Gusty winds will continue across
the far interior thru the period.

.LONG TERM (THU-SUN)...28/209 PM.

Good consensus among ensemble and deterministic guidance of high
pressure building over the region Friday and Saturday. This will
result in a warming trend into July 4th weekend as 500mb heights
continue to rise and gradients trend offshore. Temperatures will
likely warm even more into next week - however, there is quite
the range in solutions. Stay tuned for updates.

&&

.AVIATION...29/0040Z.

At 0002Z at KLAX, the marine layer was 3800 ft deep. The top of
the weak inversion was 5900 ft with a temperature of 14 C.

High confidence in VFR TAFs for KPMD KWJF, with abnormally strong
onshore winds. There is a 20% chance of clouds tonight at KPRB.

Moderate confidence for all other sites. Ceiling are expected
to develop tonight, but timing be be off by +/- 3 hours and
flight categories off by 1 category. The weak inversion
contributes to the uncertainty. 20% at each site to drop down to
IFR.

KLAX...Ceiling are expected to develop tonight, with moderate
confidence in timing (+/- 3 hours). OVC015-025 cig hieghts are
most likely. There is a 50% chance of SE winds 8-10 knots 13-17Z
Mon.

KBUR...Ceiling are expected to develop tonight, with moderate
confidence in timing (+/- 3 hours). OVC010-025 cig hieghts are
most likely.

&&

.MARINE...28/903 PM.

High confidence in Small Craft Advisory (SCA) level winds
continuing for the outer waters from the Central Coast through
San Nicolas Island through Monday morning (lingering longer for
the far northern waters), with some improvement still expected
after. The nearshore Central Coast waters should continue to see
SCA winds through late tonight, with chances decreasing Monday
and Tuesday.

Moderate confidence in SCA winds over the western Santa Barbara
Channel through late tonight, with lowering chances going
forward. The rest of the waters will likely stay under SCA.

All waters will see short-period choppy seas into early next week.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 3 AM PDT Monday for zones
      349-351-381-383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Monday for
      zones 645-650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PDT Monday for zone
      670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 AM PDT Monday for
      zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Black/Ciliberti
AVIATION...Schoenfeld
MARINE...SF/RS
SYNOPSIS...DB/RK/CC

weather.gov/losangeles

Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox