National Weather Service Raw Text Product

695 
FXUS66 KLOX 151547
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA 
847 AM PDT Wed May 15 2024

.SYNOPSIS...14/834 PM.

Consistent weather expected for the next few days. Coastal areas 
will continue to see low clouds and below normal temperatures. In 
contrast, temperatures will be above normal for interior areas, 
with gusty winds at times, especially across the Antelope Valley. 
A slight chance of showers will persist for the mountains each 
afternoon through Wednesday.

&&

.SHORT TERM (TDY-FRI)...15/846 AM.

***UPDATE***

A weak upper level low pressure system is currently centered near
San Diego, with weak east winds aloft over southwest California.
This flow has pulled in ample mid-level debris clouds from
previous convection over Arizona and Nevada. Cannot discount some
virga or a light shower from this. More importantly, this will 
provide a moisture source to interact with the unstable air 
forming this afternoon over the mountains. As a result, there is a
slight chance for showers and thunderstorms over the mountains. 
If something were to form, there is a smaller but non-zero chance 
of a shower drifting off the mountains and into the valleys with 
the easterly steering flow. 

Otherwise, low clouds and fog with patchy drizzle remains dominant
over the coastal side of the region. Look for poor clearing once
again over many coastal areas, although if convection forms over
the mountains that does tend to lead to better clearing over the
coast. Temperatures will be similar to yesterday. 

***From Previous Discussion***

The May Grey pattern will continue through the short term. An
upper low will slowly exit the area today and NE flow aloft will
develop as it arcs around an upper west of Eureka.

Todays marine layer is about 2000 ft and notably its capping
inversion is a little weaker than it was at this time ydy.
Gradients are still strongly onshore and the push to the east
could reach 10 mb this afternoon. Low clouds cover all of the
coasts and vlys as well as the Paso Robles area. Patchy drizzle is
also likely from Malibu and points north. The NE flow aloft and 
the weaker inversion may join forces to help clearing this 
afternoon. The higher hgts and hopefully better clearing should 
lead to 2 to 3 degrees of warming save for the LA coast where the 
stronger onshore flow will result in 1 to 2 degrees of cooling. As
has been the case for the past week the csts/vlys will end up 
about 6 degrees blo normal and the interior about 6 degrees above 
normal. The strong onshore push will bring gusty winds to the 
interior and low end advisory (45 mph) gusts to the westerly 
Antelope Vly foothills.

One new thing will affect today's weather. The NE flow that sets
up this afternoon will advect in just enough instability and
moisture to bring a slight chc of an afternoon and early evening
TSTM over the LA/VTA mtns and the Antelope vly.

A ridge will move over the state on Thursday pushing hgts up. The
clearing trend will be tricky as mdls show better clearing but 
the higher hgts will lead to a stronger marine inversion which 
with the strong onshore flow may well bring another afternoon of 
slow to no clearing for the coastal areas. The higher hgts will 
lead to a few degrees of warming.

No real changes on Friday. The weak ridge will continue as will
the night through morning low clouds and gusty afternoon winds.
Max temps will not change much from Thursday's values.

.LONG TERM (SAT-TUE)...15/326 AM.

The upper ridge will push off to the east on Saturday and dry SW
flow will move over the area. Ensembles favor better clearing and
some warming, but the onshore flow remains strong and would not
be surprised if clearing was not as fast and max temps come in a
little cooler than fcst.

On Sunday and Monday a fairly high hgt upper low will approach the
area from the SW. The lift from this system will reinforce the low
cloud pattern and again low clouds will push deep into the vlys
and then only clear to the coast. Patchy drizzle will be likely in
the mornings. No real strong instability or moisture signals so 
likely the only effect the low will have on convection is just 
some mtn CU. Lowering hgts, deeper marine marine layer and
stronger onshore flow will bring 3 to 5 degrees of cooling each
day. By Monday max temps across the csts/vlys will only be in the
mid and upper 60s while the vlys will only top out in the lower to
mid 70s. Max temps will be 5 to 10 degrees below normal across the
board.

Ensembles are not in the best of agreement for Tuesday but most
signal some sort of weak troffing. See no reason why the
relentless marine layer cloud pattern should stop. Hgts are 
higher than on Monday and this should result in a little warming.

&&

.AVIATION...15/0615Z.

At 0505Z at KLAX, the marine layer was 1600 feet deep. The top of
the inversion was around 3100 feet with a temperature of 16 C.

high confidence in desert TAFs.

moderate confidence in coastal/valley TAFs. There is a 20 percent
chc of LIFR conds at any site 11Z-15Z. There is a 30 percent chc 
of clearing at sites with no clearing fcst 21Z-01Z. Flight Cat 
change timing may be off by +/- 90 minutes.

KLAX...Moderate confidence in TAF. There is a 15 percent chc of
BKN004 conds 11Z-15Z. There is a 20 percent chance that there 
will be no clearing in the afternoon. Timing of flight category 
changes could be +/- 90 minutes of forecast. Good confidence that 
there will not be any east wind component greater than 5 kt.

KBUR...Moderate confidence in TAF. There is a 20 percent chc of
BKN004 conds 11Z-15Z. Timing of flight category changes could be 
+/- 90 minutes of forecast.

&&

.MARINE...15/735 AM.

Winds and seas will remain Small Craft Advisory (SCA) levels
through at least Saturday, except for a 30-50 percent chance of
SCA level winds in the vicinity of the Channel Islands and across
the western half of the Santa Barbara Channel each afternoon and
evening. 

There is a 30-50 percent chance of SCA conditions early next 
week, highest beyond 10 NM offshore and in the vicinity of the 
Channel Islands.

&&


.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect from 3 PM this afternoon to 10 PM PDT
      this evening for zone 381. (See LAXNPWLOX).
PZ...NONE.

&&

$$

PUBLIC...Rorke/Kittell
AVIATION...Rorke
MARINE...Hall/RAT
BEACHES...Hall
SYNOPSIS...Schoenfeld

weather.gov/losangeles

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