LA Area Forecast Discussion

FXUS66 KLOX 302130

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
230 PM PDT Thu Jun 30 2022

.SYNOPSIS...30/959 AM.

Onshore flow will continue to cool coastal and inland temperatures
through the weekend, and keep breezy SW winds over the Antelope
Valley. Night through morning low clouds and fog will thicken and
push further inland each day. A significant warm up is possible
later next week.


.SHORT TERM (TDY-SUN)...30/224 PM.

Current satellite imagery depicts a significant stratus deck that
is rapidly burning off over land. As broad troughing moves in, we
should continue to see a deep marine layer with clouds and fog
pushing far into the valleys over the next few nights. Thinking we
will see less clouds through the Santa Barbara Channel tonight and
over the next few nights due to reoccurring dry, northerly
sundowner winds. Also evident in satellite imagery, mid to upper
level clouds are slowly approaching in from the southwest. These
are associated with a weak disturbance, what remains of a former
tropical system. This should lead to a few more clouds over the
area today and tomorrow, and could cause some light drizzle/mist
from the marine layer tonight and Friday night. However, no
accumulations are expected.

The cooling trend continues today with highs ranging dramatically
from cool 60s along the Central Coast to hot upper 80s to mid 90s
over the interior. Falling heights and persistent onshore flow
allow for temperatures to generally fall 2-4 degrees each day
through Saturday, and a trough passes Sunday further cools the
region. By Sunday, temperatures will be 5 to 10 degrees below
normal. This onshore flow drives gusty southwest winds over the
Antelope Valley today, and each afternoon through Sunday. Winds
this afternoon will remain below advisory levels, but should
increase Friday. Sundowner winds are also firing up again tonight,
and should reoccur through Sunday night along western portions of
the Santa Barbara south coast. Sundowner winds trend stronger
into Saturday, with wind advisories most likely for Saturday and
Sunday nights. Wind advisories may be needed near Point Conception
Saturday for gusty northwest winds over the waters.

High temperatures were warmed Saturday and Sunday near the
Gaviota/Goleta area with continued Sundowner winds expected.
Otherwise, no additional changes were needed to the forecast.

.LONG TERM (MON-THU)...30/228 PM.

Ensemble (GEFS, EPS, GEPS) guidance are in good agreement Monday
and into next week, with above normal confidence in the forecast.

The long-term begins with a rather deep marine layer and plenty of
overnight to morning clouds. High pressure builds in, compressing
the marine layer leading to lower clouds and reduced visibilities
becoming more possible as we get into Thursday. This also limits
how deep the marine layer can push into the valleys so we may see
the majority of clouds and fog right at the coasts by mid-week.

Following the trough passage on Sunday, heights begin to rise as
the high centered over Texas starts shifting west over the region.
This will result in warming temperatures with continued onshore
westerly flow, limiting warming at the coasts. Temperatures should
start pushing into the 4-10 degrees above normal values by
Thursday, with lower confidence near the coasts as temperatures
may be cooler depending on the strength of the onshore flow. This
has the potential to be another significant heat wave, as heights
continue to rise to 598 DM by Friday/Saturday. Guidance shows a
potential for southerly, monsoonal flow to develop as early as
Thursday, which would also bring increased humidity to this
already hot airmass.



At 1527Z at KLAX, the marine layer was 1700 feet deep. The top of
the inversion was at 3800 feet with a temperature of 23 C.

Once a few last sites clear this morning, VFR conditions will
continue into this evening. However, KOXR could take a few more
hours to clear out from marine clouds. Then, expect similar low
cloud pattern tonight, though cigs may be slightly higher--
generally IFR to MVFR most areas, except LIFR at KPRB. The marine
clouds will get into the valleys, but the desert TAFs will remain
VFR with gusty winds.

KLAX...Moderate confidence in the 18z TAF. There is a 30 percent
chance that cigs will be higher than forecast. There is a 30
percent chance that cigs will arrive earlier than forecast. Very
good confidence that any east wind component will be less than 5

KBUR...Moderate confidence in the 18z TAF. There is a 30 percent
chance that cigs will arrive earlier than forecast.


.MARINE...30/1239 PM.

Across the outer waters, Small Craft Advisory (SCA) level winds
are expected thru late tonight across all outer waters. SCA conds
are also expected Fri afternoon thru Mon.

Across the inner waters n of Pt. Sal, there is a 30% chance of
SCA level winds during the afternoon and evening hours today, Fri
and Mon. SCA level winds are expected during the afternoon and
evening hours Sat and Sun.

Across the SBA Channel, there is a 30-40% chance of SCA level
winds across western portions during the late afternoon and
evening hours today and Fri, then SCA level winds are likely
during the afternoon through late evening hours there Sat thru
Mon. Across eastern portions of the Channel, SCA conds are not
expected thru Mon.

Across the southern inner waters, there is a 30% chance of SCA
level winds across far western portions of the zone during the
late afternoon and evening hours Sat, then SCA level winds are
likely during the afternoon through late evening hours there
Sun and Mon. Elsewhere, SCA conds are not expected thru Mon.

The gusty winds will generate short-period, choppy seas that will
likely be dangerous to mariners.


PZ...Small Craft Advisory in effect until 3 AM PDT Friday for
      zones 670-673-676. (See LAXMWWLOX).




Experimental Graphical Hazardous Weather Outlook at:

NWS LOX Office Area Forecast Discussion