837
FXUS66 KLOX 131039
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
339 AM PDT Sat Jul 13 2024

.SYNOPSIS...13/229 AM.

The long-lasting heatwave will across the mountains and interior
areas will end today as the high pressure system weakens and
pushes to the east. There will be some cooling each day through
the middle of next week. In the meantime, temperatures inland will
remain above normal. Another warming trend will develop later
next week and continue into next weekend.

&&

.SHORT TERM (TDY-MON)...13/318 AM.

A broad lobe of PVA is currently transitioning over the area. Its
has produced some showers (although probably more virga than
rain) and one small TSTM over Calabasas. The clouds associated
with this PVA are obscuring the marine layer which seems to be
much less extensive than ydy. This despite decent onshore trends
and is likely the result of no eddy development. A large lobe of
NVA is riding in on the tails of the PVA and in nicely evident on
Satellite. This NVA should decrease the chc of TSTMs as well as
the cloud cover. Clearing skies will allow for instability to
develop late this morning and afternoon over the interior and
another slgt chc (~20 percent) of showers and/or TSTMs will
develop there. The showers will be quite high based and there is
threat of downbursts and dry lightning. One last day of heat for
the interior which despite a few degrees of cooling will still
reach dangerously high values. The reduced marine layer will allow
the coasts and vlys to rebound from the big cool down ydy due to
the eddy.

The upper high remains near the four corners area on Sunday. Hgts
fall enough to bring a degree or 2 of cooling to the area. The
onshore gradients do not change much and the low cloud pattern
should be similar today. Not totally out of the woods as far as
convection is concerned but it looks like all of the moisture
will be around 600mb so a non zero but less than 12 percent chc of
a shower in the afternoon more likely just a bunch of build ups.
Max temps will only be 4 to 6 degrees above normal and near normal
across the coasts and vlys.

On Monday the east Pac trof pushes close enough to the coast to
switch the flow the SW which will dry things out and eliminate the
convective threat. Otherwise a pretty dull day with coastal low
clouds in the morning and otherwise clear skies. Max temps will be
similar to Sunday`s.

.LONG TERM (TUE-FRI)...13/337 AM.

Tuesday will be the coolest day of the next 7 as the east Pac
trof makes it`s closest approach to the coast. Hgts fall to about
592 dam and the onshore flow increases to the highest value of
the week. Max temps will fall another couple of degrees. Most max
temps will end up 2 to 4 degree blo normal save for the Antelope
Vly which will remain 2 or 3 degrees above normal.

The the upper high will build back to the west and hgts will
increase and temps will rise. Look for a couple of degrees of
warming each day Wed through Saturday. Onshore flow will continue
and there will be night through morning low clouds across the
coasts. Barring an unforeseen eddy the vlys will remain cloud
free. The marine layer will keep the coasts cooler but the vlys
will be about 5 degrees above normal by Saturday and the interior
will be about 10 degrees. Right now it looks like the monsoon will
keep to the east but this could change.

&&

.AVIATION...13/0713Z.

At 0523Z at KLAX, the marine layer was 1300 feet deep. The top of
the inversion was at 4300 feet with a temperature of 30 deg C.

Moderate confidence in TAFs for KPRB, KPMD, and KWJF. For these
sites, there is a 10% chance for thunderstorms thru 14Z and a 20%
chance 14Z-03Z.

Moderate confidence in TAFs for KBUR and KVNY. There is a 30%
chance of LIFR cigs and IFR vis 11Z-15Z.

Moderate confidence in coastal TAFs. Vis will likely vary
frequently through 15Z. Cig hgts may be off by +/- 300 ft. VFR
transition may be off by +/- 2hours.

KLAX...Moderate confidence in TAF. There is a 30 percent chc of
Cigs remaining AOA OVC005. There is a 30 percent chc that Vis
will remain AOA 3SM. If Vis does drop below 3SM it will likely
vary frequently between 1SM and 3SM. Low clouds may arrive as late
as 07Z tonight. No significant easterly wind component is
expected.

KBUR...Moderate confidence in TAF. There is a 30 percent chance
of 2SM BR OVC004 conds 11Z-15Z.

&&

.MARINE...13/321 AM.

Small Craft Advisory (SCA) conditions are not expected through
the weekend. There is a 30-40% chance of SCA winds across the
Outer Waters starting Monday afternoon through the week.
Additionally, there is a 20-30% chance of SCA winds across the far
western portion of the Santa Barbara Channel during each
afternoon through overnight hours beginning Monday through the
week. A long period south swell is expected to arrive Tuesday and
may lead to a chance for elevated surf conditions and high rip
current potential through Thursday.

Dense fog will continue across the coastal waters through the
morning. Please reference the Marine Weather Statement for
additional information.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Excessive Heat Warning remains in effect until 9 PM PDT this
      evening for zones 38-343>345-353-376>379-381>383. (See LAXNPWLOX).
     Fire Weather Watch in effect from 9 AM PDT this morning
      through this evening for zones 342>345-348-351>353-376>383. (See LAXRFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Rorke
AVIATION...Rorke
MARINE...Lund/Lewis/Phillips
SYNOPSIS...MW

weather.gov/losangeles

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