Walnut, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

723
FXUS66 KLOX 270344
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
844 PM PDT Thu Jun 26 2025

.SYNOPSIS...25/158 PM.

Night and morning low clouds and fog will affect the coasts and
some valleys, otherwise mostly clear skies are expected across
the area with gusty onshore winds each afternoon. Temperatures
will continue to turn a bit warmer tomorrow, with little change
over the weekend into early next week.

&&

.SHORT TERM (THU-SUN)...26/843 PM.

***UPDATE***

In general, southern California remains in a relatively benign
weather pattern with plenty of coastal marine layer clouds and
warm temperatures for the interior. Highs peaked in the upper 90s
to near 100, with much cooler values for areas that remained stuck
in clouds for most of the day. The marine layer this evening was
about 700 feet at LAX, so there will be the potential for fog to
grow dense in spots. Onshore gradients remain stronger though,
less than ideal for widespread dense fog tonight. The current
forecast looks on track, with only some minor edits made to the
stratus coverage.

***From Previous Discussion***

Overall, 12Z models in good synoptic agreement through the short
term period. At upper levels, the area will remain sandwiched
between high pressure building over the 4 Corners area and an
upper low spinning off Point Conception. Near the surface,
moderate onshore flow will continue.

Forecast-wise for the short term, no significant issues are
expected. Main challenge will be forecasting the extent of the
marine layer stratus. Today through Saturday, H5 heights will
increase slightly which should help make the marine inversion more
shallow. So, inland extent of the stratus should be a bit less
each of the next couple of nights. However by Saturday night, H%
heights will fall slightly as the upper low exerts a bit more
influence. So, inversion will deepen slightly and stratus will
push a bit further inland Saturday night/Sunday morning. Each
afternoon, stratus should dissipate nicely for most areas although
stratus could remain stubborn along the beaches, especially from
Ventura south to Malibu. Other than stratus, skies should remain
mostly clear through the period.

As for temperatures, afternoon highs will be at the whim of the
marine layer and surface gradients. Overall, most areas should
see a slight warming trend through Saturday with less marine
influence, but a bit of cooling on Sunday as marine influence
increases slightly. Overall, changes from day-to-day will not be
significant.

As for winds, no significant issues are expected. The moderate
onshore pressure gradients will generate the typical gusty
southwesterly winds across interior sections, but speeds will
remain below advisory levels. Additionally, there will be some
localized Sundowner winds each evening, but again, nothing
expected to be problematic.

.LONG TERM (MON-THU)...26/148 PM.

For the extended, 12Z models continue to exhibit decent synoptic
agreement. On Monday/Tuesday, the upper low offshore of Point
Conception will move inland across Central California. For
Wednesday and Thursday, the low will open up into a trough and the
trough will linger over the area.

Forecast-wise, the weather pattern should remain rather benign.
Main challenge will continue to be the marine layer stratus. For
Monday/Tuesday, will expect deeper marine inversion (as H5 heights
lower) and more inland extent of night/morning stratus/fog
(pushing into the Santa Clarita Valley). For Wednesday and
Thursday, H5 heights increase slightly which should result in some
shrinking the inversion and less inland extent of stratus/fog.
Other than the stratus, skies are expected to remain mostly clear
through the period.

As for temperatures, minor day-to-day changes can be expected. For
Monday/Tuesday, most areas will exhibit some slight cooling.
However for Wednesday/Thursday, that will reverse with a slight
warming trend across the area.

With continued moderate onshore pressure gradients, gusty
southwesterly winds can be expected each afternoon/evening across
interior sections. However, speeds should remain below advisory
levels.

&&

.AVIATION...26/2350Z.

At 2326Z at KLAX, the marine layer was 1200 ft deep. The top of
the inversion was at 2700 ft with a temperature of 25 C.

High confidence in VFR TAFs for KPMD and KWJF.

Low confidence in TAF for KPRB. There is a 40% chance for VLIFR
conds between 11Z and 17Z.

Moderate confidence in remaining TAFs. For KBUR and KVNY, there
is a 30% chance conds remain IFR. For KLAX there is a 20% chance
for brief LIFR conds, and for KSMO, 30% chance minimum flight cat
doesn`t go below IFR. For KOXR, SCT conds may briefly occur
between 01Z and 03Z. There is a chance for brief LIFR cigs at
KOXR (20%) and KSMO (30%). Otherwise, flight cat changes may be
off by 2 hours at all sites.

KLAX...Moderate confidence in TAF. There is a 20% chance for
brief OVC003-004 cigs between 06Z and 16Z. Otherwise, flight cat
changes may be off by 2 hours. There is a 20% chance for no
clearing tomorrow. No significant east wind component expected.

KBUR...Moderate confidence in TAF. There is a 30% chance for cigs
to remain OVC005 or higher once cigs arrive. Flight cat changes
may be off by 2 hours.

&&

.MARINE...26/835 PM.

Small Craft Advisory (SCA) level winds and steep short period
seas of 7 to 9 feet will continue across the Outer Waters and
Inner Waters along the Central Coast through late tonight and into
early Friday morning, with Gale Force (34 kt) wind gusts in the
northern Outer Waters through late tonight.

Elsewhere and otherwise, no hazardous winds or seas are expected
through early next week. However, night to morning dense fog is
possible through the weekend, especially adjacent to the Central
Coast.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 3 AM PDT Friday for
      zones 645-676. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Friday for zone 670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 AM PDT Friday for zone
      673. (See LAXMWWLOX).

&&

$$

PUBLIC...Phillips/Thompson
AVIATION...Lewis
MARINE...Lewis
SYNOPSIS...Lewis

weather.gov/losangeles

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