Channel Islands Beach, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

751
FXUS66 KLOX 302151
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
151 PM PST Mon Dec 30 2024

.SYNOPSIS...30/230 AM.

An extended period of gusty north to northeast winds is expected
through through the end of the week. A warming trend will start
today and continue through the rest of the next week especially
mid week when the Santa Ana winds arrive and high pressure builds
over the area.

&&

.SHORT TERM (TDY-THU)...30/139 PM.

Overall, 12Z models in good synoptic agreement through the short
term period. At upper levels, ridge will gradually build over the
area through Thursday. Near the surface, weak to moderate offshore
flow will prevail.

Forecast-wise for the short term, main issue will be the potential
for offshore winds. As another weak system passes by to the north
tonight, the north to northeast offshore pressure gradients will
strengthen. Looking at high resolution models, pressure gradients
will increase to moderate levels. However, the upper level wind
and thermal support will remain lacking. Therefore, current
expectation is for a weak to locally moderate Santa Ana wind event
across the area through Thursday (with the strongest winds likely
Tuesday through Wednesday). Given the expected weak nature of the
event, do not anticipate any widespread advisory-level winds
across the usual Santa Ana corridor of Ventura/LA counties. This
matches up well with the HREF only indicating a 20-30% chance of
advisory-level winds in these areas. However, based on the
strength of the northerly gradients tonight as well as the HREF
solutions, there is a good chance of advisory-level winds across
the entire Santa Ynez Range as well as the Santa Lucia Mountains
tonight and Tuesday morning. So with the afternoon forecast, will
issue WIND ADVISORIES for these area through Tuesday morning.

Otherwise, no significant issues are expected. Still will expect
some stratus/fog across the coastal plain south of Point
Conception tonight/Tuesday morning as weak offshore flow should
not be enough to wipe out the stratus/fog. However for Tuesday
afternoon through Thursday, stratus/fog should not be an issue.
However, skies will likely vary between mostly clear and partly
cloudy as high clouds drift overhead. As for temperatures, will
expect a warming trend with offshore surface flow and rising
thicknesses/H5 heights. In fact by Wednesday/Thursday, most areas
west of the mountains will top out in the 70s to around 80.

.LONG TERM (FRI-MON)...30/139 PM.

For the extended, no significant issues are expected. For Friday
and Saturday, an upper level trough will move across the West
Coast. Most of the energy with this system will remain well north
of the area. Overall, skies will be partly to mostly cloudy
through Saturday with some return of coastal stratus/fog. For
Friday night/Saturday morning, there is a chance of some rain
north of Point Conception, but amounts, if any, will be very
light. With the clouds and return of more typical onshore flow,
temperatures will exhibit a cooling trend.

For Sunday and Monday, models begin to differ, leading to some
differences for the forecast. The GFS indicates a weak diurnal
flow while the ECMWF develops weak offshore flow. Given the trends
so far this winter, will skew the forecast towards the ECMWF
solution. So, will have some locally gusty offshore winds as well
as a gradual warming trend for most areas.

Looking into the crystal ball further out, models still do not
indicate any chance of appreciable rain for the area through the
middle of January. Also, will have to monitor the potential for a
warm (for this time of year) and more significant Santa Ana wind
event in the January 7th-9th time frame.

&&

.AVIATION...30/1821Z.

At 17Z at KLAX, the marine layer was around 1100 ft deep. The top
of the inversion was at 4400 ft with a temperature of 19 C.

Overall, moderate confidence in 18Z TAF Package. Highest
confidence in KPRB, KSBP, KSMX, and desert sites (KPMD, KWJF).
Wind gusts could be off 5 kts at times.

Low confidence in remaining TAFs. Timing of cigs/vsby restrictions
may be off +/- 3 hours. Flight cats could be off one or two,
especially during worst conditions.

KLAX...Low confidence in 18Z TAF. There is a 30-40% chance of
1/2-3/4SM and 353. (See LAXNPWLOX).
     High Surf Advisory in effect until 9 PM PST this evening for
      zone 354. (See LAXCFWLOX).
     Red Flag Warning in effect from noon Tuesday to 6 PM PST
      Wednesday for zones 369-370-375-379. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect until 9 PM PST this evening
      for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 PM PST Tuesday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Thompson
AVIATION...Black
MARINE...Black
BEACHES...Schoenfeld/Lewis/Black
SYNOPSIS...MW

weather.gov/losangeles

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