Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 07/06/22

Area Forecast Discussion

National Weather Service Los Angeles/Oxnard CA

 738 PM PDT Tue Jul 5 2022

.SYNOPSIS...05/142 PM.

Low pressure parked over the Pacific Northwest will bring little
change through Wednesday, with below normal temperatures and
morning low clouds and fog over many coastal and valley areas.
Gusty southwest to northwest winds will form over the favored
areas each afternoon and night, strongest over Santa Barbara
County. A warming trend is expected later this week into the
weekend and will likely last through next week.

&&

.SHORT TERM (TUE-FRI)...05/738 PM.

***UPDATE***

Overall, a relatively quiet evening across the forecast district.
Latest satellite and surface observations indicate some stratus
and fog over the coastal waters and some beaches with clear skies
elsewhere. Current AMDAR sounding data indicates marine inversion
around 1000 feet deep. As for winds, some northerly winds, gusting
around 35 MPH, are occurring across the western Santa Ynez Range.

Forecast-wise for the immediate short term, main concern will be
the Sundowner winds across the western Santa Ynez Range. Offshore
gradients remain strong enough overnight to produce gusts of
35-50 MPH across the area (especially the Gaviota and Refugio
areas). So, current WIND ADVISORY for this area looks good through
300 AM Wednesday. Otherwise, only weather issue overnight will be
the marine layer stratus. Do not anticipate much deepening of the
inversion overnight. So with the continued onshore gradients,
stratus and fog should become widespread across the coastal plain
and push into the coastal valleys. Otherwise, skies will remain
clear.

Overall, current forecast has good handle on the immediate short
term. So, no significant updates are anticipated at this time.

***From Previous Discussion***

Low pressure off British Columbia moving very little and keeping
temperatures below normal locally. Even the deserts which average
in the mid to high 90s this time of year aren`t even reaching 90.
The upper low will slowly move north over the next few days as
high pressure across the southern half of the US expands into
California. This will bring about a slow warming trend that will
begin Thursday and continue into next week. In the meantime,
another couple days of below normal temperatures, most notably
felt across inland areas where highs are from 5-10 degrees below
normal. Marine layer stratus again will be fairly solid along the
Central Coast and across LA County, with lesser amounts over
Ventura County and definitely southern Santa Barbara County where
more Sundowner winds across the western portion will create
downsloping that will hinder cloud development.

Normal to above normal temperatures expected to return Friday as
high pressure expand west and the air mass warms. Nothing too
dramatic as a moderate onshore flow will remain in place, but we
could see temps approaching 100 in the Antelope Valley and mid to
high 90s back in the warmer valleys. This isn`t as warm as some
ensemble members had indicated initially, however there`s a chance
of those higher numbers coming later on in the forecast period.

.LONG TERM (SAT-TUE)...05/139 PM.

The high pressure system that will be expanding west later this
week is expected to settle over the 4 corners region by early next
week with a slight weakening of onshore flow. This will likely
continue the warming trend for several more days, eventually
pushing coastal valley highs into the lower 100s and farther
interior areas to around 105 or possibly higher. This could happen
as soon as Sunday with only minimal changes through the middle of
next week. A much smaller but statistically significant
percentage of ensemble members show Antelope Valley highs going
above 110 later next week into the following weekend with warming
temps also across the coast and coastal valleys, so at the very
least there`s a good chance of a lengthy period of above normal
temps with a possibility of extreme heat across the interior beyond
the current 7 day forecast window.

&&

.AVIATION...05/2227Z.

At 2220Z, the marine inversion at KLAX was based at 1500 feet.
The top of the inversion was 2700 feet with a temperature of
19 degrees Celsius.

Overall, moderate to high confidence in 00Z TAF package. Moderate
confidence is for coastal and valley TAFs due to uncertainties
with the arrival of marine layer stratus (both timing and flight
category). High confidence for desert TAFs.

KLAX...Moderate confidence in 00Z TAF. High confidence in return
of CIG/VSBY restrictions, but only moderate confidence in timing
(could be +/- 2 hours of current 07Z forecast) and flight category
(40% chance that restrictions develop at MVFR levels). No
significant easterly wind component is expected.

KBUR...Moderate confidence in 00Z TAF. High confidence in return
of CIG/VSBY restrictions, but only moderate confidence in timing
(could be +/- 3 hours of current 11Z forecast).

&&

.MARINE...05/738 PM.

For the Outer Waters, moderate to high confidence in current
forecast. For tonight, high confidence in Small Craft Advisory
(SCA) level winds across PZZ673/676. On Wednesday, there will be
a temporary lull in the winds, but from Wednesday night through
Sunday, high confidence in SCA level winds for the entire Outer
Waters. Additionally, there is a 30% chance of Gale force winds
Thursday night through Saturday.

For the Inner Waters north of Point Sal, moderate to high
confidence in current forecast. Tonight through For Wednesday
through Wednesday, high confidence in winds and seas remaining
below SCA levels. For Thursday through Sunday, there is a 50-60%
chance of SCA level winds, especially during the afternoon and
evening hours.

For the Inner Waters south of Point Conception, moderate to high
confidence in current forecast. For the western half of the Santa
Barbara Channel, there is a 50% chance of SCA level winds tonight
through Sunday during the late afternoon through overnight hours.
Elsewhere across the southern Inner Waters, high confidence in
winds and seas remaining below SCA levels tonight through Sunday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 6 AM PDT Wednesday for zones
      349-351. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Wednesday for
      zones 650-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW/Thompson
AVIATION...RAT
MARINE...RAT
SYNOPSIS...MW

weather.gov/losangeles

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