Acton Weather

000
FXUS66 KLOX 230105
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
605 PM PDT Wed Sep 22 2021

.SYNOPSIS...22/124 PM.

Increasing onshore flow will bring cooling to most areas Thursday
and Friday with high temperatures back to normal levels. The
cooling trend is expected to continue into next week.

&&

.SHORT TERM (TDY-SAT)...22/129 PM.

A very warm day inland, similar to or slightly warmer than
yesterday`s temperatures. Along the coast trends are definitely
cooler, as much as 10 degrees in some areas as a robust sea breeze
arrived earlier. Forecast on track for tomorrow with cooling
pushing farther inland. Some coastal valley areas will be down 10
degrees from today`s levels.

A little northerly flow will develop across southwestern Santa
Barbara County this evening and bring some breezy low grade
Sundowners there. Will likely see some gusts in the 30s around
Gaviota but otherwise below advisory levels. That northerly flow
will help minimize stratus formation tonight so skies should stay
mostly clear south of Pt Conception but expect we`ll see some
patches of low clouds around. Still solid coverage along the
Central Coast tonight with some patchy dense fog, though slight
lifting of the marine layer should mitigate that somewhat.

For Friday either not much change or slight cooling. Overall a
similar day as Thursday though with increasing marine layer
stratus for coastal zones south of Pt Conception.

Models continue to struggle with the handling of a trough and
eventual pinching off of a closed low late Friday into Saturday.
At one time models showed this happening off the coast of Pt
Conception but now the favored location is northern Baja. This
puts So Cal in an easterly flow pattern aloft with some energy
and moisture wrapping around, though mostly south of LA County.
Will keep in some low pops for the eastern LA Mountains and
Antelope Valley but not looking particularly favorable at this
time. Still a chance the low could make a closer pass to our area
and require some increasing of pops but for now staying pretty
conservative given the daily model fluctuations. Temperature-
wise probably very similar to Friday.

.LONG TERM (SUN-WED)...22/137 PM.

Hard to have too much confidence in a detailed extended forecast
given the difficulties models are having in the short term. And
big ensemble spreads in temperatures next week also a sign that
the range of possible solutions is still quite high. However, in
general the vast majority of the models point towards a cooler
pattern through mid week. A few solutions suggest some light
precip associated with another trough coming through the region
but it`s still early in the season for that and would defintely
favor a dry solution right now.

&&

.AVIATION...23/0104Z.

At 2349Z at KLAX, the marine layer was 600 ft deep. The top of
the inversion was at 1500 feet with a temperature of 29 C.

High confidence in desert and valley TAFs. Moderate to low
confidence in coastal TAFs, where marine layer clouds may
dissipate and reform at times tonight. Moderate confidence in VFR
conditions for the L.A. coast with a 20% chance of 3-5SM vis and
IFR to LIFR cigs around 14Z. There is a 30% chance for cigs at
KOXR from 11Z- 15Z.

There will be locally gusty N winds thru and below passes and
canyons of southern SBA County this evening into late tonight,
mainly from Refugio westward, with some LLWS and mdt UDDF.

KLAX...Moderate confidence in the 00Z TAF. There is a 20% chance
of IFR to LIFR cigs around 14Z Thu. No significant east wind
component is expected.

KBUR...High confidence in the 00Z TAF with VFR conditions thru
the period.

&&

.MARINE...22/1241 PM.

Lower than normal confidence in the forecast for this afternoon
and evening. Winds are already starting to increase in the coastal
waters which tends to support the earlier issued Small Craft
Advisory (SCA) across the southern two outer waters zones
(PZZ673/676), a good portion of the Santa Barbara Channel, and
much of the southern inner waters from mid afternoon thru at least
midnight. However, there is a 30-40% chance that winds will
remain below SCA levels. Otherwise and elsewhere, winds and seas
are expected to be below SCA levels thru Sun. With the shallow
marine layer, there will be areas of dense fog across the coastal
waters this morning.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory in effect until 8 PM PDT this evening for zones
      44>46-88-547. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Thursday for
      zones 650-655-673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK (SAT-WED).

No significant hazards expected.

&&

$$

PUBLIC...MW
AVIATION...Phillips/Sweet
MARINE...Sweet
SYNOPSIS...MW

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