Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 06/29/19

Area Forecast Discussion...UPDATED

National Weather Service Los Angeles/Oxnard CA

 822 PM PDT Fri Jun 28 2019

.SYNOPSIS...28/821 PM.

Weakening onshore flow and a thinning marine layer will bring a
warming trend, especially away from the coast, through the
weekend. Night through morning low clouds and fog will persist
mainly across the coastal plain. A cooling trend is possible for
early next week as onshore flow strengthens.

&&

.SHORT TERM (TNT-MON)...28/805 PM.

Southwest flow aloft continues between an upper-level trough of
low pressure over the Pacific Northwest and an upper-level ridge
of high pressure near the New Mexico-Colorado border. An onshore
flow pattern remains across the area, albeit weaker than the last
several days. A persistent marine layer in place over the area
will likely remain in place but will thin into Saturday and
Sunday as the high pressure system to the east will continue to
strengthen. The latest AMDAR soundings from KLAX and RAOB sounding
from KVBG indicate a marine layer depth near 1000 feet deep. Less
marine layer stratus coverage should be expected through the
weekend, likely becoming confined to the coast on Saturday night
and into Sunday morning. A warming trend will continue through the
weekend, sharpest across the interior portions of the area.

With the thinning marine layer, patchy dense fog cannot be ruled
out, especially from Santa Barbara north with any low clouds and
fog that form.

The current forecast trends look reasonable and no further updates
are planned.

***From Previous Discussion***

The other potential factor this weekend, mainly Saturday night
and Sunday, is the moisture and energy coming up from what is
currently still TS Alvin. Models and their respective ensemble
members are in pretty unanimous agreement in keeping precip out of
the area but we should at least see a sizable increase in high
cloud coverage late Saturday into Sunday morning, mainly LA County
but possibly into Ventura County as well.

The onshore trends that will begin Sunday afternoon will continue
into Monday likely resulting in a slightly cooler day for
coast/valley areas and slightly later marine layer clearing.
Otherwise a pretty typical early summer day.

.LONG TERM (TUE-FRI)...28/130 PM.

Minimal day to day changes most of next week as the upper pattern
remains largely unchanged and moderate onshore flow will continue
through at least Thursday. Expect stratus coverage to expand to
all coastal areas Tuesday and most coastal valleys. Temperatures
will be near to a couple degrees above normal. Models are showing
the AZ high building in even stronger by next weekend and onshore
flow weakening so it`s looking probable that we`ll see a warming
trend as early as Friday.

&&

.AVIATION...28/2325Z.

At 2130Z, the marine layer depth was around 1200 feet deep at
KLAX. The top of the marine inversion was near 3000 ft with a
temperature around 21 degrees Celsius.

Low to moderate confidence in the current forecast. Higher
confidence in coastal terminals. Less confidence in valley
terminals.

North of Point Conception, there is a chance of LIFR to IFR
conditions, mainly between 08Z and 16Z at coastal terminals,
otherwise VFR conditions will persist through the period.

South of Point Conception, IFR to MVFR conditions are likely,
mainly between 06Z and 16Z at coastal terminals. There is a
chance of an earlier arrival at Los Angeles County coastal
terminals. Higher confidence in MVFR conditions from KLAX south.
There is a chance LIFR conditions mainly north of KOXR.

KLAX...There is a 30 percent chance of MVFR conditions by 02Z
increasing to 60 percent between 06Z and 08Z. MVFR conditions
will likely persist to between 17Z and 18Z. There is a 30 percent
chance LIFR conditions between 02Z and 15Z.

KBUR...There is a 30 percent chance of IFR conditions between 13Z
and 16Z, otherwise VFR conditions will likely persist.

&&

.MARINE...28/814 PM.

For the Outer Waters...Small Craft Advisory (SCA) conditions
will continue through at least early Sunday morning and likely
extending into early Monday morning across the waters north and
west of the Channel Islands. There is a 50 percent chance of SCA
level winds across the entire outer waters Mon thru Wed.

For the nearshore waters north of Point Sal...local SCA winds
will linger across pockets of the nearshore waters late tonight.
There is a 40 percent chance of SCA level winds each afternoon
and evening through Sunday, then there is a 50 percent chance of
SCA level winds Monday afternoon through Wednesday.

For the Inner Waters south of Point Conception...winds and seas
are expected to remain below SCA levels through Monday. There
will then be a 40 percent chance of SCA level winds in the SBA
Channel Monday afternoon through Wednesday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 9 PM PDT this evening
      for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Monday for
      zones 670-673. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Sunday for zone
      676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK (MON-FRI).

No significant hazards expected.

&&

$$

PUBLIC...Hall/MW
AVIATION...Hall
MARINE...Hall
SYNOPSIS...Hall

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