134
FXUS66 KLOX 151659
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
959 AM PDT Sat Jun 15 2024

.SYNOPSIS...15/959 AM.

Warm to hot conditions are expected today, with some cooling
expected Sunday and Monday. A slow warming trend is expected for
the middle of next week. Strong to locally damaging north to
northwest winds will affect much of southern Santa Barbara County,
the Interstate 5 cooridor, and most mountains through Monday
morning. The strongest winds for the area around Santa Barbara
City will be this afternoon and night. Gusty winds will also
affect the western Antelope Valley and foothills, some Los Angeles
County Valleys, and the Central Coast today and tonight.

&&

.SHORT TERM (TDY-MON)...15/953 AM.

***UPDATE***

Broad downsloping offshore winds from the north have kept skies
clear for most all of the region. Compressional heating overnight
into this morning has driven temperates upward dramatically for
many foothill areas. The current 24 hour temperature change ranges
from 15 to 25 degrees for areas along the southern Ventura County
Mountains and into the foothills of the Santa Clarita and San
Fernando Valley. For the Santa Barbara South Coast and many cities
along the Central Coast, the 24 hour temperatures change is
around 10 to 15 degrees. Based on these observed trends,
daytime highs have been increased for these areas, with near 100
degrees possible for the warmest locations.

Temperature gradients will be sharp between the coasts and
foothills for Santa Babara South Coast, ranging from the low 80s
to around 100 degrees in the span of just a few miles. Compared to
previously very temperate June Gloom conditions this month, heat
impacts will be significant for the coastal foothills of Santa
Barbara City and the Ojai Valley. A Heat Advisory is in effect
for the Santa Barbara County South Coast and adjacent mountains,
and there is 20-30% chance that further advisories will be issued
for today for the interior valleys of Ventura and LA County
(especially the Ojai Valley). Heat related precautions are
advised.

Strong temperature gradients will be present throughout in the
region, including the San Fernando Valley, as warm downsloping
wind competes with the cooling marine influence (our natural air
conditioning). Skies are sunny except for a small amount of
clouds over Long Beach and off the coasts of Los Angeles. This
indicates continued southerly flow and cooling marine influence
for the eastern Los Angeles County Coast. This will moderate
temperatures for coastal cities near the Pales Verdes Peninsula,
and intensify the temperature gradient between the coasts and
coastal valleys.

***From Previous Discussion***

Gusty northwest to north winds were occurring across much of SBA
County, the mtns of Ventura County, the I-5 Corridor and the
foothills of the Antelope Valley early this morning, with wind
gusts near or above advisory levels in many of these areas.
As expected, it remained very warm in some of the foothill
locations in southern SBA County, and in L.A. County with
temps still around 80 degrees in some of these areas.

A broad upper level trough will sag southward across the forecast
area today and tonight, causing westerly flow aloft to increase.
At the same time, NW to N winds at 700 mb and 850 mb will
strengthen today. Northerly winds closer to the surface will also
increase, driven by continued sharpening N-S offshore gradients
which will peak this evening at 5.5 mb between KSBA and KSMX.
In addition to all of this, there will be increasing broad scale
subsidence across the region later today into tonight, helping to
force winds toward the surface.

Expect an increase in winds today, with High Wind Warning level
gusts to 60 to 65 mph likely across portions of southern SBA
County, the mountains of Ventura County, through the I-5 Corridor
and in the Antelope Valley foothills. Advisory level winds are
expected to push in the Santa Clarita Valley as well. Have
expanded Wind Advisories to include the Central Coast from late
this morning through this afternoon. Have also included Wind
Advisories for western portions of the Antelope Valley floor from
this afternoon through late tonight. There is a chance that
advisory level winds will affect the Santa Susana mtns, and the
northern San Fernando Valley, but for now, have kept winds just
below thresholds.

On the Central Coast, winds should peak this afternoon. In most of
the remaining windy locations, expect the winds to peak this
evening and early tonight. This particular sundowner wind event
is expected to be rather widespread across southern Santa Barbara
later today and tonight. Winds will likely affect many highly
populated areas in the city of Santa Barbara and near Montecito
and the adjacent foothills this afternoon into tonight.

Warming at 950 mb and increased northerly flow should bring
warming to most of the region today, except in the mtns, the
Antelope Valley and the interior valleys of SLO County, where
there should be slight cooling. Compressional warming of the
downslope winds will likely bring very warm to hot weather to
much of southern SBA County, including much of the city of Santa
Barbara, and possibly even to near the beaches. High temperatures
should rise into the 90s to around 100 in the foothills and
interior portions of the city, and 90 degree temps may well reach
some beach locations.

There will likely be a very sharp temperature gradient near the
coast of southern Santa Barbara County today. Confidence in temps
reaching 90 degrees at the beaches is not especially high, since a
very low inversion may prevent the winds and heat from reaching
immediate beach locations. However, this particular pattern seems
more likely than most to bring hot weather to the immediate south
coast, especially late in the day. This will be quite a dramatic
change from the very cool spring weather that has been the norm
this year.

While Sunday is not expected to be quite as hot as today will be,
gusty north winds tonight will likely keep temps in the 70s or
near 80 in the foothills all night, providing limited relief.
Therefore, a Heat Advisory is in effect through Sun evening for
the south coast of SBA County, and the Santa Ynez Range.

The combination of gusty winds, very warm to hot conditions,
and lowering humidities will bring elevated fire weather
conditions to southern Santa Barbara county and much of the
interior valleys, mountains, and Antelope Valley this weekend
(See Fire Weather Planning Forecast for more details on fire
weather concerns).

Heights will continue to lower across the region tonight and Sun
as the broad trough deepens slightly and sags southward. Expect
limited low clouds tonight/Sun morning, though clouds will likely
affect at least coastal sections of L.A. County, and possibly
southern Ventura County due to a developing eddy circulation. The
strong winds will likely dimish below warning levels by mid
morning Sun, but N-S gradients will remain remaining steep, so
advisory level winds may continue across southern SBA County, in
the mtns of Ventura County and through the I-5 Corridor through
Sun evening. Expect a few degrees of cooling in most areas Sun,
though temps should still be above normal for the middle of June.

An upper low will move into the Pac NW Sun night and Mon, with a
sharpening trough across CA. N-S gradients will decrease, though
they should remain steep enough for additional gusty winds late
Mon into Mon night across southern SBA County. Onshore gradients
will increase between KLAX and KDAG. Expect more widespread night
thru morning low clouds and fog Sun night/Mon. Lowering heights,
and cooling through the atmosphere should bring several degrees of
cooling to most of the region on Mon.

.LONG TERM (TUE-FRI)...15/522 AM.

The trough will linger across the region Mon night and Tue, but
heights will rise a bit. Night thru morning low clouds should be
widespread in most coastal and in the lower valley areas, but
northerly gradients may keep southern SBA County clear, with
another round of gusty winds. Max temps on Tue should be similar
to those Mon, with perhaps a couple of degrees of warming.

Models are now showing a broad trough lingering across the region
Wed thru Fri, but with gradual height rises. The general pattern
looks conducive to widespread night thru morning low clouds in
most coastal and lower valley areas. A strengthening inversion and
increasing onshore flow may make for slower clearing, especially
near the coast.

N-S gradients, while weaker, should still be strong enough to
maintain gusty northwest to north winds in terrain-favored areas
such as the I-5 corridor, northern VTU County mtns, and southern
SBA for much of next week. For the most part, expect wind gusts to
remain below Wind Advisory thresholds Wed thru Fri, with perhaps
a 20-30% chance of Wind Advisory level winds, especially in
southern SBA County. Max temps should rise slightly in most areas
Wed thru Fri, with the greatest warming across inland locations.
By late next week, max temps could get close to 100 degrees in the
Antelope Valley and the far interior valleys of SLO County.

&&

.AVIATION...15/1643Z.

At 1600Z at KLAX, the marine layer was 1000 ft deep. The top of
the inversion was at 5000 ft with a temperature of 25 C.

Overall, moderate to high confidence in TAF package.

CAVU conditions are anticipated at most locations through the
period. However, CIG/VSBY restrictions in the returning marine
layer affect coastal LA County tonight and Sun morning, including
KLAX and KLGB. Onset timing of CIG/VSBY restrictions may vary by
+/- 2 hours from current forecasts. Gusty northerly winds will
develop today and continue through the TAF period, and there
could be some light turbulence/LLWS across the mountains and
foothills.

KLAX...Moderate to high confidence in TAF. There is a 40% chance
that CIG/VSBY restrictions do not develop. No significant
easterly wind component is expected.

KBUR...High confidence in TAF as CAVU conditions are anticipated
through the period.

&&

.MARINE...15/931 AM.

For the Outer Waters, high confidence in current forecast. Winds
have increased to Gale force levels and will remain at Gale force
levels through Monday. So, GALE WARNINGS will remain in place
through Monday (with a 20% chance of Storm force winds today
through Sunday night). Seas will peak in the 12 to 15 foot range
today through Monday. For Tuesday through Wednesday, winds will
subside, but remain at Small Craft Advisory (SCA) levels while
seas drop below 10 feet.

For the Inner Waters north of Point Sal, moderate to high
confidence in current forecast. There is a 60-80% chance of Gale
force winds today through Sunday and a GALE WARNING remains in
effect. Seas will peak in the 10 to 13 foot range through Sunday.
For Monday through Tuesday, there is a 60-80% chance of SCA level
winds. On Wednesday, winds and seas are expected to remain below
SCA levels.

For the Inner Waters south of Point Conception, moderate to high
confidence in current forecast. For the western Santa Barbara
Channel, high confidence in SCA level winds increasing to Gale
Force Winds today and continuing at Gale force levels through
Sunday with a GALE WARNING remaining in effect. For Monday through
Wednesday, there will be a 60-80% chance of SCA level winds across
the western half of the Santa Barbara Channel. Elsewhere across
the southern Inner Waters, there is a 20-30% chance of SCA level
winds today through Sunday with high confidence in winds and seas
remaining below SCA levels Monday through Wednesday.

Across all of the coastal waters, steep and dangerous seas can be
expected this weekend into at least early next week.

&&

.BEACHES...15/147 AM.

Short-period wind waves, due to gale force winds, will generate
significant surf conditions along the local beaches today through
Monday. High surf conditions, 4 to 8 feet, will impact the
beaches of Ventura county. For the beaches along the Central Coast
as well as Los Angeles county, elevated surf conditions will
continue through Monday. Along with the surf conditions, dangerous
rip currents can be expected through the weekend.

&&

.FIRE WEATHER...15/944 AM.

&&

Rapidly increasing northwest to north winds are expected to continue
through early next week, peaking in intensity through tonight with a
secondary peak late Sunday into early Monday. Wind gusts of 30 to 50 mph
will be common at times through the period for the Central Coast,
mountains of Santa Barbara, Ventura and northwest Los Angeles County as
well as Antelope Valley (strongest in the mountains and deserts).
Isolated gusts to 65 mph will be possible in the strongest periods of
wind across the Santa Ynez Range and I-5 corridor. Meanwhile, the air
mass will warm and dry, with widespread 8 to 15 percent humidities in
the mountains and deserts. High temperatures between 90 and 100 will be
common inland of the beaches. Poor overnight recoveries in the foothills
are also expected. This warm and dry air will descend into some coastal
foothills, including southern Santa Barbara County. As a result, there
is an elevated risk for fast growing grass fires over much of the area,
that could transition into wildfires where the fuel beds are most
abundant and dry.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through Monday evening for
      zones 87-340-346-362-366. (See LAXCFWLOX).
     Wind Advisory remains in effect until 11 AM PDT Sunday for
      zone 88. (See LAXNPWLOX).
     Wind Advisory in effect until 8 PM PDT this evening for zones
      340-341-346-347. (See LAXNPWLOX).
     High Wind Warning remains in effect until 11 AM PDT Sunday
      for zones 349-351-376>378-381. (See LAXNPWLOX).
     Heat Advisory remains in effect until 8 PM PDT Sunday for
      zones 349>352. (See LAXNPWLOX).
     Wind Advisory remains in effect until 6 PM PDT this evening
      for zones 350-352-353. (See LAXNPWLOX).
     High Wind Warning remains in effect from 6 PM this evening to
      11 AM PDT Sunday for zones 350-352-353. (See LAXNPWLOX).
     High Surf Advisory in effect until 7 PM PDT Monday for zone
      354. (See LAXCFWLOX).
     Wind Advisory in effect from 3 PM this afternoon to 3 AM PDT
      Sunday for zone 383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 11 AM PDT this morning
      for zones 645-650. (See LAXMWWLOX).
     Gale Warning in effect until 2 AM PDT Monday for zones
      645-650. (See LAXMWWLOX).
     Gale Warning in effect until 7 PM PDT Monday for zones
      670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...DB/Schoenfeld
AVIATION...Cohen/RAT
MARINE...RAT/Cohen
BEACHES...RAT
FIRE...Munroe/Gomberg
SYNOPSIS...DB/RS

weather.gov/losangeles

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