Duarte Weather

000
FXUS66 KLOX 251137
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
437 AM PDT Tue Jun 25 2019

.SYNOPSIS...25/115 AM.

Night through morning low clouds will continue to cover the coasts
and valleys through the end of the week, otherwise mostly clear
skies will prevail. Daily maximum temperatures will continue below
normal through Friday and will then warm.

&&

.SHORT TERM (TDY-THU)...25/222 AM.

Today and Wednesday will be near carbon copies of Monday. Strong
offshore flow both the north and the east. This coupled with a
strong inversion will bring low clouds to the coastal slopes
overnight and then slow clearing in the vlys and limited to no
clearing over the coastal areas. Weak lift from the cyclonic aloft
along with the strong onshore flow will produce patchy drizzle
this morning across the csts/vlys and especially the foothills
areas. The Below normal temps will continue. The coasts will be 5
to 10 degrees below normal, the vlys 10 to 15 degrees blo normal
and the interior will end up 3 to 6 degrees under normals.

A little upper level disturbance will move move the area today and
will bring an increase in mid and high level clouds to the area.

The strong onshore flow will generate gusty afternoon and evening
winds across the mountains and deserts. Wind speeds will flirt
with advisory-levels, but expect any advisory-level winds to be
localized in wnd prone areas such as Lake Palmdale.

An unseasonably large and cool upper low will move into the PAC
NW on Thursday. It will lower hgts and the stronger cyclonic will
lift the marine layer. There will be offshore trends and this will
allow for better clearing although there is a chc that the marine
layer will deepen enough to set up a reverse clearing scenario.

.LONG TERM (FRI-MON)...25/315 AM.

Both the GFS and EC agree that the large upper low will slowly
move across Washington state on Friday. Hgts do not change much
but the onshore flow to the east will weaken and actual offshore
flow will develop from the north. This will keep the clouds from
covering all of the vlys and will lead to a quicker burn off. Max
temps will rise everywhere.

The north flow will bring some local winds to the I-5 corridor as
well as the SBA south coast but right now the parameters strongly
favor sub advisory gusts.

On Saturday hgts will rise a large upper high expands in from the
east. At the same time offshore flow will continue from the north
and will develop across the Central Coast. Between the higher hgts
squashing the marine layer down and the offshore flow pushing it
away the marine layer stratus will be confined to the SBA south
coast and the LA/VTA coasts and perhaps portions of the lower
vlys. Max temps will jump everywhere esp in the vlys and many
areas will see near normal temps in the afternoon.

A little mdl disagreement starts in on Sunday as the EC reasserts
the trof while the GFS keeps pushing the ridge over the area. More
ensemble members from both the GFS and EC favor the warmer GFS
solution and biased the fcst that way.

The mdl disagreement continues on Monday only more so. The EC has
a cloudier cooler soln and the GFS continues with a warmer upper
ridge soln. Looking at all of the ensembles it looks like GFS has
a better probability of verifying. The forecast continues the
Sunday weather with minimal marine layer stratus and warmer temps.

July 4th just appeared in the mdls day 10 window and unfortunately
the EC and the GFS are diametrically opposed. The EC has a cool
579 DM trof while the GFS has a roasty-toasty 591 DM upper high.

&&

.AVIATION...25/1136Z.

At 0838Z at KLAX, the marine layer was 2800 feet deep. The top of
the inversion was around 3500 feet with a temperature near 20
degrees Celsius.

N of Point Conception...Moderate confidence with IFR Cigs for
coast and KPRB. 30% chance for brief LIFR conds between 12z-14z.
in the current forecast. Flight cat transitions could be off by
+/- 1 hour. Moderate confidence with persistent stratus pattern
once again this evening through early Wed morning. There is a 20%
chance that CIGs might linger all day along coastal TAFs.

S of Point Conception...Moderate confidence with MVFR Cigs. There
is a 50% chance for IFR Cigs for KSBA, KOXR and KCMA through 15z.
Flight cat transitions could be off by +/- 1 hour. Moderate
confidence with persistent stratus pattern once again this evening
through early Wed morning. There is a 20% chance that L.A.
coastal TAFs might scatter out between 21-00z this afternoon.
linger all day along coastal TAFs.

KLAX...Moderate confidence in the current forecast. Flight cat
transitions could be off by +/- 1 hour. There is a 20% chance
that L.A. coastal TAFs scatter out between 21-00z this afternoon.
Good confidence that there will not be an east wind component
greater than 6 kt.

KBUR...Moderate to high confidence in the current forecast.
There is a 30% chance that MVFR CIGs could linger until 22z.

&&

.MARINE...25/254 AM.

For the Outer Waters, winds and seas will likely remain below
Small Craft Advisory (SCA) levels through early Wednesday, with
a 70 percent chance of SCA level winds across the northern zone
(PZZ670)by Wednesday afternoon. Higher confidence that the entire
outer waters will need a SCA by Wednesday evening. Small craft
advisory winds should continue Thursday through Saturday, with a
50 percent chance of gales between Thursday afternoon and Friday
night.

For the Inner Waters north of Point Sal, winds and seas will
likely remain below SCA levels through early Wednesday, then there
is a 60 percent chance of SCA level winds each afternoon and
evening between Wednesday and Saturday.

For the Inner Waters south of Point Conception, winds and seas
will likely remain below SCA levels through early Wednesday, then
a 40 percent chance of SCA level winds across the western half of
the Santa Barbara Channel Wednesday late afternoon and evening,
then a 50% chance each afternoon and evening between Thursday and
Saturday for the same western portion of the Santa Barbara Channel.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

.HAZARD POTENTIAL OUTLOOK (THU-MON).

No significant hazards expected.

&&

$$

PUBLIC...Rorke
AVIATION...Kaplan
MARINE...Kaplan/Gomberg
SYNOPSIS...30

weather.gov/losangeles

NWS LOX Office Area Forecast Discussion