342
FXUS66 KLOX 012116
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
216 PM PDT Mon Jul 1 2024

.SYNOPSIS...01/141 PM.

A significant heatwave will impact a large part of the area this
week and continue into next weekend. Temperatures will become
dangerously hot across much of the area. High temperatures by mid
to late week are expected to reach 95 to 105 degrees in many areas
away from the coast, with highs upwards of 105 to 115 over
interior valleys and foothills including the Antelope Valley.
Also, by late week, very warm to hot conditions could extend
closer to the coast. Patchy night and morning dense fog will be
possible near the coast early this week.

&&

.SHORT TERM (TDY-THU)...01/202 PM.

Just very minimal changes to the 7 day forecast. High pressure
aloft will expand across the west this week, peaking Friday and
Saturday with dangerously hot temperatures inland. Excessive heat
watches for the valleys have been converted to warnings and
extended to next Monday. Existing heat warnings across the
interior continue and have also been extended to next Monday.

In the short term, still dealing with the marine layer along the
coast and locally into some of the valleys. With the high
expanding this week the marine inversion will be lowering a little
each day. Tuesday is a borderline day for stratus into the
valleys but then after that any low clouds and fog should be
confined to the coast at most. Highs will be warming each day
through Saturday, especially away from the immediate coast.
Onshore flow to the east will remain in place though weakening
with time. Gradients to the north will remain fairly light at
least through Thursday. So no significant winds expected in the
short term except typical onshore sea breezes each afternoon.

.LONG TERM (FRI-MON)...01/215 PM.

The heat will really kick in later in the week into Saturday as
the high pressure center over northern California reaches 600dam.
Models still indicating some northerly flow developing across the
Central Coast and southern Santa Barbara County as well as the
northern mountains, creating a favorable pattern for hot
Sundowners Friday and Saturday evenings. While the hottest
temperatures will still be across inland area, strong downsloping
slow off the Santa Ynez Mountains will provide a temperature boost
across the coastal areas of southern Santa Barbara County with
highs well into the 90s possible and very warm overnight
temperatures as well.

Elsewhere, temperatures will continue to warm through Saturday.
Highs inland will be 10-15 degrees above normal and at the coast
5-10 degrees above normal with minimal and early clearing of
marine layer. Models are suggesting a few degrees of cooling
Sunday but then very little change Monday. While it`s possible
that temperatures may technically drop into more of heat advisory
category in some previously warned areas Sunday/Monday, opted to
just extend the Excessive Heat Warning through Monday.

The combination of these very hot temperatures, areas of low
humidities and possible sundowner winds will lead to fire weather
risks. Please see the fire weather discussion below for all the
details.

&&

.AVIATION...01/1631Z.

At 1615Z at KLAX, the marine layer was 1600 feet deep. The top of
the inversion was at 2800 feet with a temperature of 24 Celsius.

For 18Z TAF package, high confidence in KPRB, KBUR, KVNY, KPMD and
KWJF TAFs as CAVU conditions are expected thru the period.

For 18Z Coastal TAFs, low to moderate confidence in current
forecast. Timing of return of CIG/VSBY restrictions could be +/- 4
hours of current forecasts.

KLAX...Moderate confidence in 18Z TAF. Timing of return of
CIG/VSBY restrictions could be +/- 3 hours of current 08Z
forecast. Also, there is a 40% chance of LIFR conditions 08Z-16Z.
No significant easterly wind component is expected.

KBUR...High confidence in 18Z TAF as CAVU conditions are
anticipated thru the period.

&&

.MARINE...01/1141 AM.

For the Outer Waters, moderate to high confidence in current
forecast. Through tonight, high confidence in Small Craft Advisory
(SCA) level winds. For Tuesday through Thursday, high confidence
in winds and seas remaining below SCA levels. For Friday and
Saturday, there is a 20-30% chance of SCA level winds.

For the Inner Waters north of Point Sal, moderate to high confidence
in current forecast. There is a 40-60% chance of SCA level winds
through this evening. For Tuesday through Saturday, high
confidence in winds and seas remaining below SCA levels.

For the Inner Waters south of Point Conception, high confidence in
current forecast. Today through Saturday, winds and seas will
remain below SCA levels.

Patchy dense fog (with visibilities one nautical mile or less)
will continue to impact the coastal waters through the week. The
areal coverage of the dense fog will likely decrease each day.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Excessive Heat Warning now in effect from 11 AM Tuesday to 6
      PM PDT Monday for zones 38-343>345-353-376>379-381>383. (See LAXNPWLOX).
     Excessive Heat Warning in effect from 11 AM Wednesday to 6 PM
      PDT Monday for zones 88-342-348-351-352-356>358-369>375-380. (See LAXNPWLOX).
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 Tuesday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW
AVIATION...RAT
MARINE...RAT
SYNOPSIS...Cohen

weather.gov/losangeles

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