507
FXUS66 KLOX 191604
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
904 AM PDT Sun May 19 2024

.SYNOPSIS...19/856 AM.

Low clouds will continue to be a staple of the forecast for coast
and valleys through Monday, and struggling to clear each
afternoon. Breezy onshore winds will occur across the interior
valleys and adjacent foothill areas each afternoon and evening.
More sunshine with slight warming is expected Tuesday and
Wednesday as onshore flow weakens. Then cooler with increasing
marine layer clouds again the latter half of next week.

&&

.SHORT TERM (TDY-TUE)...19/903 AM.

***UPDATE***

Our deep marine pattern continues as a long wave upper level
trough remains in place along the West Coast of North America.
Low clouds will again be slow to clear today and temperatures will
be 4-8 degrees below normal. Strong onshore flow remains as well
so it will be another breezy day in the Antelope Valley.

***From Previous Discussion***

Monday looks to be the coolest day of an already cool week. Look
for a weak and dry upper low to pass over Srn CA. Look for an even
deeper marine pushing well into the mtn passes (possible moving
through the Soledad canyon and into Palmdale). Areas of morning
drizzle are likely. While there is likely going to be another
round of slow to no clearing, there is a chance the marine layer
will deepen to the point of collapse and there will be decent
clearing. While the csts/vlys will cool by 1 to 3 degrees the
interior will drop 4 to 8 degrees. Max temps across the csts/vlys
will only be in the 60s with just a couple 70 degree readings. Max
temps will end up 6 to 12 locally 15 degrees blo normal.

Short range deterministic and ensemble forecasts all area that
there will be 3 to 4 mbs of offshore trends (weaker onshore flow)
on Tuesday. Look for much quicker and better clearing across the
board along with 4 to 8 degrees of warming due to weaker
seabreezes and higher hgts.

.LONG TERM (WED-SAT)...19/317 AM.

Relentless long wave troffing will dominate the long term
forecast. At the same time the east pac will reassert itself while
thermal low will also be present in the afternoon. This will lead
to a steady day by day increase in the onshore flow with a double
digit push to the east next Friday and Saturday afternoons. Look
for a steady increase in marine layer coverage with slow to no
clearing rearing its head later in the week and heading into the
weekend. The gusty afternoon winds will also return with low end
advisory level gusts likely in the western Antelope Vly. Max temps
will cool a little on Wednesday and then drop 3 to 6 degrees on
Thursday with little change on tap for Friday and Saturday. Look
for another round of max temps mostly in the 60s for the csts and
vlys or 5 to 10 degrees blo normal.

&&

.AVIATION...19/1151Z.

At 0805Z at KLAX, the marine layer was 2600 ft deep. The top of
the inversion was at 4200 feet with a temperature of 16 C.

Good confidence in desert TAFs.

Moderate confidence in the remainder of TAFs. There is a 30
percent chc that sites with afternoon clearing will remain cloudy.
Flight Cat transitions may be off by +/- 90 minutes and cig hgts
off by +/- 300 ft.

KLAX...Moderate confidence in TAF. There is a 30 percent chc of
BKN025 conds through the afternoon. BKN025 cigs may arrive
anytime between 14Z and 16Z. No significant E wind component
expected.

KBUR...Moderate confidence in TAF. There is a 20 percent chc of
BKN025 conds through the afternoon. BKN025 cigs may arrive
anytime between 15Z and 17Z.

&&

.MARINE...19/148 AM.

High confidence in Small Craft Advisory (SCA) seas and/or
northwest winds forming tonight over the offshore waters from the
Central Coast to San Nicolas Island. There is a 30 percent chance
of SCA for the western Santa Barbara Channel each evening. These
conditions will continue through Monday and likely beyond. Seas
will be building everywhere as a result, with short period
dominant seas over most nearshore waters by Sunday Night or
Monday. SCA conditions are unlikely elsewhere. Southeast winds
will form each morning over the nearshore waters from Santa
Barbara to Orange County starting Monday or Tuesday. These winds
can enhance to near 15 knots through passages and channels.

A long period south to southwest swell will peak Sunday and Monday
with heights of 2 to 4 feet. This will create larger than usual
breaking waves nearshore as well as some stronger currents near
most harbor entrances.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through Monday evening for
      zones 87-362-366. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect from 2 PM this afternoon to 3
      AM PDT Tuesday for zone 670. (See LAXMWWLOX).
     Small Craft Advisory in effect from 9 PM this evening to 3 AM
      PDT Tuesday for zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW/Rorke
AVIATION...Rorke
MARINE...Kittell
SYNOPSIS...MW

weather.gov/losangeles

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