Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000
FXUS66 KLOX 252024
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
124 PM PDT Sun Jun 25 2017

.SYNOPSIS...
High temperatures continue away from the coast today. Offshore
trends and a weakened marine layer will warm the coastal valleys
as well. A trough of low pressure off the California Coast will
weaken high pressure aloft beginning Monday afternoon and bring a
cooling trend as onshore flow strengthens.

&&

.SHORT TERM...(TDY-WED)

Temperatures really soaring today under increased sunshine, a
lack of morning marine lyr clouds, and northwest low lvl flow.
Some places seeing temps as high as 25 degrees higher than
yesterday at 1pm. Today is expected to be the warmest of the next
7 at least as a trough develops over the Pacific NW and the strong
ridge that has been in place for the past week gets knocked down a
bit and onshore flow increases, particularly Tuesday and
Wednesday. In the meantime, northwest low lvl flow will continue
to prevent much marine lyr formation south of Pt Conception but it
should remain pretty solid along the Central Coast.

Today is expected to be the last day of any heat advisories or
warnings as temperatures fall below critical levels Monday and
continue to do so through the week. By Tuesday or Wednesday most
areas should be back to normal high temps. Marine lyr expected to
expand to cover most coast and valley areas by Wednesday.

Pretty strong northwest gradients expected across the Santa Ynez
Range the next couple days but very minimal support aloft. So
while there will be gusty winds there they should generally
remain below advisory levels with the strongest winds up in the
foothills. Increasing westerly winds expected in the Antelope
Valley, especially Tuesday and Wednesday when they may be close to
advisory levels in the foothills.

.LONG TERM...(THU-SUN)

Nothing really remarkable in the weather from mid week on as we
maintain a fairly typical late June pattern. Weak troughing now
expected to remain in place going into next weekend with minimal
day to day changes in temps (near to slightly below normal) and
marine lyr coverage (coast/valleys night and morning).

&&

.AVIATION...25/1800z.

At 1753z at KLAX... the inversion was around 600 feet. The top of
the inversion was around 2500 feet with a temperature of about 33
degrees Celsius.

Moderate confidence in the coastal TAFs and high confidence in the
TAFs further inland. The central coast is the most likely location
to see marine clouds overnight. Only moderate confidence exists
for the south coastal locations to have any marine clouds
overnight...the current forecast is that the clouds will not make
it to the south coast. Further inland, VFR conditions are
expected through Monday. Gusty winds are likely in the afternoon
and evening for the Antelope Valley.

KLAX...Moderate confidence in the 18z TAF. There is a 30 percent
chance of marine clouds sneaking into the airfield during the
night.

KBUR...High confidence in VFR conditions through Monday.

&&

.MARINE...25/900 AM.

For the Outer Waters... Small Craft Advisory (SCA) level
conditions will continue through at least Tuesday evening. Wind
speeds may weaken to below SCA levels during the morning hours but
will strengthen again in the afternoon.

For the Inner Waters... SCA level winds will develop in the afternoon
and evening hours through Tuesday evening across the northern
nearshore waters as well as in the East Santa Barbara Channel.
Local gusts up to 25 kt could also develop during this time from
Point Mugu to San Mateo Point west of Santa Catalina Island.

In addition to the elevated winds, a short period west to
northwest swell could impact the coastal waters Monday through
Wednesday.

&&

.FIRE WEATHER...25/1000 AM.

Hot and dry conditions with gusty winds will continue through
Monday. Although a cooling trend will begin Monday...very dry
conditions are likely to persist into Tuesday. The hot and
unstable conditions will bring the potential for plume dominated
fires which can create their own intense winds. Gusty west to
northwest winds will impact interior portions of the forecast area
through Tuesday. For Los Angeles County, the strongest winds will
be in the I-5 corridor in the mountains as well as the Antelope
Valley foothills with gusts between 30 to 40 mph. Humidities in
the single digits to teens are expected across the mountains,
deserts, and interior valleys.

For Santa Barbara County, Sundowner winds will affect the western
portions of the Santa Ynez range and South Coast (mainly from
Gaviota to Goleta), with gusts of 30 to 40 mph each evening
through Tuesday. In addition, localized humidities falling to
between 15 and 25 percent can be expected in the Santa Ynez
mountains and adjacent canyons where the downslope Sundowner winds
develop.

The combination of hot and dry conditions with locally gusty winds
will bring elevated fire weather concerns to interior sections
through Tuesday, with brief critical conditions likely each
afternoon and evening in wind-prone areas...especially Monday
afternoon and evening. If fire ignition occurs, dangerous fire
behavior should be expected. As such, the public should be extreme
careful when handling potential ignition sources such as
cigarettes, campfires, hand torches and metallic weed trimmers.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory in effect until 9 PM PDT this evening for zones
      38-52>54-88. (See LAXNPWLOX).
     Excessive Heat Warning in effect until 9 PM PDT this evening
      for zone 59. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Wednesday for
      zones 645-650-670-673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK...(WED-SUN)
No significant hazards expected.

&&

$$

PUBLIC...MW
AVIATION...Sweet
MARINE...Sweet
FIRE...Gomberg/Smith
SYNOPSIS...jld

weather.gov/losangeles



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