050
FXUS66 KLOX 161010
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
310 AM PDT Fri Aug 16 2024

.SYNOPSIS...16/225 AM.

A high pressure system over the region will weaken and move east
over the coming days as an upper-level trough moves into the
Pacific Northwest. A cooling trend with increased onshore flow
will continue through the weekend, then some warming will develop
over the early half of next week.

&&

.SHORT TERM (TDY-SUN)...16/309 AM.

Very benign weather will continue across Srn Ca for the 3 day
short period. Over the next three days an upper high over the
CA/AZ border will shift to the east while at the same time an
upper low to the N will move southward. The effects over SRN CA
will be a switch to SW flow aloft that will strengthen with time.
594 dam hgts this morning will fall to 588 dam by Saturday
afternoon and then rebound slightly Sun. At the sfc there will be
weak to moderate onshore flow to the east and weak occasionally
offshore flow in the N/S direction.

Marine layer cloud coverage is a little more robust that it has
been over the last few nights. A weak eddy has spun up and there
are some low clouds moving from Long Beach into the Oxnard. Low
clouds should increase further tonight into Saturday morning as
hgts lower. The low cloud coverage will shrink Sunday morning as
the offshore flow from the north increases slightly.

The onshore push to the east will be a little stronger today and
this will cool the coasts a few degrees. Northerly flow however
will bring warmer air into the interior where max temps will warm
3 to 4 degrees. Look for 2 to 4 locally 5 to 6 degrees of cooling
Saturday as the hgts lower and onshore increases. Less marine
layer, slightly higher hgts and a stronger offshore push from the
north will bring a little warming to the area Sunday.

Last evenings Sundowner event did not live up to expectations with
gusts almost all in the 30 to 40 mph range. The winds will be
weaker tonight and there is not threat of advisory winds.

Monsoonal thunderstorm activity is not favored through the
weekend, although the outer edge of a moisture surge may bring
some high clouds to the region tomorrow afternoon. This moisture
is expected to be too elevated to increase thunderstorm chances,
which continues to be well under 10 percent.

.LONG TERM (MON-THU)...16/309 AM.

The latest deterministic mdls and ensembles are in good agreement
on the general upper level pattern for the xtnd period. The upper
high will strengthen and move to the west on Monday and Tuesday.
On Wednesday and Thursday a PAC NW trof will move into the state
and push the upper high back to the east.

Hgts will climb each day through Tuesday and will peak around 595
dam on Tuesday afternoon. to 595 dam. Look for 2 to 4 degrees of
warming each day. By Tuesday afternoon the only 70s will be right
at the beaches with 80s and lower 90s across the rest of the
coasts. The vlys will see max temps from 92 to 104 degrees. There
will be plenty of triple digit heat across the far interior and
lower mtn elevations as well. These temps are about 6 degrees
above normal. While it will be warm these temps will only pose a
moderate heat risk. There is a 15 percent chc that the current
temp forecast is too low and there would be a need for heat
products across the interior and some of the vlys.

Lowering hgts and onshore flow will arrive Wed and continue into
Thu. Look for 2 to 4 degrees of cooling each day.

The significant high pressure will likely suppress most if not
all marine layer clouds on Mon and Tue. The lowering hgts will
bring an more conducive environment for low cloud formation Wed
and Thu mornings.

Monsoonal moisture transport into the region becomes a bit more
likely on Tuesday. Even so, at this point the chance of actual
convection remains less than 10 percent.

&&

.AVIATION...16/0553Z.

At 05Z at KLAX, the marine inversion was 600 ft deep. The top of
the inversion was 1500 ft with a temperature of 28 deg C.

High confidence in generally CAVU 06Z TAFs for KPRB, KSBA, KOXR,
KCMA, KBUR, KVNY, KPMD, KWJF. Exception is brief MVFR vsbys late
tonight into Fri morning at KSBA, KOXR and KCMA.

Moderate confidence in the 06Z TAFs for the LA coastal airfields.
There is a 40%-50% chance of IFR cigs between 11Z to 17Z at KLAX
and KLGB, and a 20% chance of these conds at KSMO.

Moderate confidence in the 06Z TAFs for KSMX and KSBP. There is a
40-50% chance of VLIFR conds at KSMX between 11Z-16Z due to
cigs/vsbys, and the arrival of cigs could be off by +/- 2 hours
from TAF time. There is a 10%-20% chance of IFR-LIFR cigs/vsbys at
KSBP between 12-15Z.

KLAX...Moderate confidence in the 06Z TAF. There is a 40%-50%
chance of IFR cigs between 11Z to 17Z, or that they occur only
briefly during this time. There is also a 40%-50% chance of IFR
cigs moving in aft about 09Z Fri night. No significant east wind
component is expected.

KBUR...High confidence in the CAVU 06Z TAF.

&&

.MARINE...16/216 AM.

For the outer waters from Point Piedras Blancas to San Nicolas
Island, high confidence in SCA level winds for all the waters thru
tonight, and for the waters west and south of Point Sal Saturday
through Sunday night. There is a chance (30%-40%) of SCA wind
gusts at times for all the outer waters Monday through Tuesday
night.

For the inner waters north of Point Sal, moderate to high
confidence in SCA level winds and/or steep seas through late
tonight. There is then a 30% chance of SCA conditions afternoons
and evenings over the weekend, and a 20%-30% chance afternoons and
evening Monday and Tuesday.

For the Santa Barbara Channel, high confidence in winds below SCA
levels through Saturday. There is then a 30% chance of SCA wind
gusts at times for the western portions of the channel each late
afternoon to evening Saturday night through Tuesday. In the
eastern portion, high confidence in conditions remaining below
SCA level through the period.

For the southern inner waters, high confidence in conditions
staying under SCA levels through Tuesday night.

With a shallow marine layer, there is moderate confidence in
patchy dense fog with visibilities under 1 nautical mile
effecting the Central Coast waters and southern inner waters
through this morning.

&&

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

&&

$$

PUBLIC...Rorke
AVIATION...Sirard
MARINE...Sirard
SYNOPSIS...Hall

weather.gov/losangeles

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