Area Forecast Discussion
Issued by NWS Los Angeles, CA

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FXUS66 KLOX 242044

144 PM PDT Sat Jun 24 2017

The high pressure ridge overhead will continue the warm
temperatures in most areas, except along the coast, through early
next week. Night through morning low clouds and fog will continue
into next week. As the high pressure weakens and onshore flow
increases, a cooling trend is expected to develop by Tuesday.



Unstable air mass in place with plenty of high level moisture
around. Had one cell take off right at the Ventura/Kern County
line near Frazier Park with plenty of lightning (most of it cloud
to cloud) but very little precip reaching the surface. Models
maintain good instability through the afternoon but with very
little moisture below 15k ft it`s going to be tough for precip to
survive the fall through the dry air. Still, a few areas could see
some sprinkles through the evening, mainly interior SLO county
and inland LA/Ventura counties. Primary concern would be for dry
lightning and gusty winds should a storm initiate.

Air mass will stabilize overnight and Sunday should be back to
normal, but with less marine layer coverage and warmer temps.
There were a few areas today that had enough cloud cover to
moderate temps but that won`t be an issue Sunday.

A slow cooling trend will begin Monday and continue into Tuesday
as the ridge aloft weakens and a trough approaches OR and northern
CA. Marine lyr likely will remain confined to the Central Coast
and LA County as there`s a strong enough northwest gradient to
limit the northward push of the low clouds through the bight. That
gradient will be enough to generate some gusty winds through the
Santa Ynez Range in srn SB County the next few night but support
aloft is minimal and not expecting winds to reach advisory levels.


Cooling trend to continue into Wed and then little change Thu
before a ridge begins to develop Friday into Saturday and temps.
Marine lyr expected to deepen and expand to all coast/valleys by
mid week but clear off to the beaches. High temps should fall back
to normal levels Tue or Wed then a little below normal Thu before
rebounding slightly going into the weekend.



At 1744Z at KLAX, the marine layer depth was around 1400 feet.
The top of the inversion was around 4500 feet with a temperature
near 30 degrees Celsius.

Low to moderate confidence in the 18z TAFs. The strip of mid level
clouds near the coast has disrupted the marine clouds with only
patches of clouds near the coast. The LA coast has the most marine
clouds to contend with and sct v bkn conditions may last another
few hours before things clear out again. The marine clouds should
regroup again with IFR conditions becoming reestablished in
mainly the LA castal sections again tonight.

KLAX...Low to moderate confidence in the 18z TAF. Sct v Bkn
conditions are likely for a couple of hours until the skies clear
out later this afternoon. The marine clouds will return with IFR
conditions this evening. There is a 30 percent chance of the
marine clouds arriving plus or minus two or more hours from the
forecasted time.

KBUR...Moderate confidence in the 18z TAF. There is a 20 percent
chance of marine clouds sneaking into the airfield early Sunday
morning. Otherwise, VFR conditions are expected through Sunday.


.MARINE...24/200 PM.

The winds are gradually increasing across the coastal waters. A
low end SCA continues in the outer zones as well as 645 and the
west end of the Santa Barbara Channel. There is a 40 percent
chance that the winds will not be strong enough for SCA in 670 and
645. Otherwise, the forecast confidence is decent.

A 2-3 foot south swell with a 16-17 second period will last
through today and may pose a risk for breaking waves nearshore.
People boating or kayaking near shore should use extra caution.


CA...Heat Advisory in effect until 9 PM PDT Sunday for zones
      38-52>54. (See LAXNPWLOX).
     Beach Hazards Statement in effect until 10 PM PDT this
      evening for zones 40-41-87. (See LAXCFWLOX).
     Excessive Heat Warning in effect until 9 PM PDT Sunday for
      zone 59. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 9 PM PDT this evening
      for zones 645-650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Monday for
      zones 670-673-676. (See LAXMWWLOX).


No significant hazards expected.



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