October 27, 2020 Red Flag Warning - Los Angeles County San Gabriel Valley (California)
56.6 °F
Dew Pt.
21.2 °F
1017.1 hPa 
  rising slowly
0.0 mph 
0.00 in 
  0.00 in/hr
UV index
Solar rad.
100 W/m²

Today: Sunny, with a high near 77. Breezy, with a northeast wind 10 to 20 mph, with gusts as high as 30 mph.
Sunny and
Breezy then

Tonight: Mostly clear, with a low around 49. North northeast wind 5 to 10 mph.
Mostly Clear

Hi 77 °F Lo 49 °F
FXUS66 KLOX 271204

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
504 AM PDT Tue Oct 27 2020

.SYNOPSIS...27/259 AM.

Gusty Santa Ana winds are expected to continue through this afternoon,
though weaker than yesterday. Sub-freezing temperatures are expected
across the Antelope Valley early this morning. A warming trend is
expected through much of the week with continued weak offshore
flow. The marine layer should redevelop by this weekend across
coastal areas.


.SHORT TERM (TDY-THU)...27/308 AM.

Santa Ana winds will continue to affect the wind prone areas of
Los Angeles and Ventura Counties through this afternoon. Strongest
N-NE winds were occurring across the L.A. County Mountains and
the Santa Monica Mtns where gusts were ranging in the 30s to near
50 mph. Winds will pick-up around sunrise through the morning
hours, but will not be as strong as yesterday`s damaging winds.
The LAX- DAG surface gradient will be around 2 MB weaker today as
the colder air advection at 850-950mb that filtered into the high
desert and mountains yesterday will moderate a bit warmer today.
Also, there will continue to be some upper level support mainly
across L.A County to keep most of the strongest winds across the
San Gabriel Mtns where a High Wind Warning will remain in effect
through mid afternoon where peak gusts 60-65 mph are expected,
strongest this morning.

Wind advisories will remain in effect for the Santa Clarita, San
Fernando Valley and the Ventura County Valleys where peak gusts
will be 45 mph. The wind advisory for the San Gabriel Valley will
be cancelled with the morning forecast as only local gusts to 35
mph are expected across the windiest canyons in the foothills.
The Wind Advisory for the L.A. Coast will be limited to between
Malibu and the Hollywood Hills this morning before the seabreeze
kicks in late this morning. The Ventura County Coast could see
local gusts to 35 mph this morning, but overall gusts should
remain below advisory thresholds. See LAXNPWLOX for the latest
information on the various wind products. The Red Flag Warning in
effect for much much of L.A. and Ventura Counties will continue
through 6 PM this evening due to the continued offshore winds and
single digit humidities.

A Hard Freeze Warning is also in effect for the Antelope Valley
this morning, mainly for the wind protected areas as weaker winds
and very dry air will allow for efficient radiational cooling lowering
temperatures to sub-freezing 26-29 degrees for a few hours this morning.
Temperatures will moderate warmer for Wednesday morning, so not
expecting any freeze concerns.

Skies through Thursday will remain mostly clear with minimal
chances for low clouds to reestablish due to weak offshore flow.
Smoke from the fires in Orange County will continue to impact the
coastal areas of LA county (especially around the Long Beach area)
through this afternoon. Additional warming expected Wed/Thu, though
mainly for interior areas as light onshore trends for the latter
half of the week lead to some cooling closer to the beaches with
minimal chances for the marine layer to re- establish.

.LONG TERM (FRI-MON)...27/255 AM.

Models are in pretty good agreement through early next week with
large scale synoptic features. A ridge of high pressure will
persist over the region through Friday, then weaken some this
weekend before a weak upper level trough moves through the area.
High temperatures should remain around normal or slightly higher
through Sunday before cooling early next week. There is a better
chance of low clouds becoming more established Friday or this



At 1130Z, there was no marine inversion at KLAX.

Except for a smoke layer across southern L.A. County this morning
with MVFR conds this morning, VFR conds are expected through the
period, with just some high clouds. There will be some gusty north
to northeast winds through early this afternoon across the
mountains of L.A. County, the northern and western valleys of L.A.
County, the eastern valleys of Ventura County, and coastal
sections of L.A. County from Malibu to the Hollywood Hills.
There will be areas of LLWS and moderate to strong UDDF especially
in the mtns and valleys through this afternoon.

KLAX...High confidence in the 12Z TAF with VFR conds expected
through the period. There is a 10-20% chance of MVFR conditions
due to vsbys or a smoke layer through 18Z. There is a 20% chance
of east to northeast winds reaching 8 to 10 knots through 18Z.

KBUR...High confidence in the 12Z TAF with VFR conds expected
through the period. There is a 20% chance that LLWS may persist
through 21Z. There is a 20-30% chance of NE winds gusts to
between 25 and 30 knots from 15Z to 21Z.


.MARINE...27/447 AM.

Moderate to high confidence that N to NE winds will reach Small
Craft Advisory (SCA) levels this morning across the inner waters
from Ventura to San Mateo Pt. and across portions of the southern
outer waters zone (PZZ676). Winds will be strongest from Ventura
to Santa Monica and out to Anacapa and Santa Cruz Islands and
south of Palos Verdes thru the San Pedro Channel to Catalina
Island. Local gale force gusts to 35 kt are possible this morning.

In addition to the winds, dangerous and steep seas are expected
and northeast wind waves will affect east and northeast facing
harbor entrances such as Avalon Harbor and Two Harbors on
Catalina Island, and Smugglers Landing on Santa Cruz Island.
These places should NOT be considered safe harbor this morning.

Winds and seas are not expected to be as high as they were on
Monday. Winds are expected to shift to NW and diminish some this
afternoon, but there is a 30-40% chance that winds will remain at
SCA levels in some areas thru this evening.

After today, winds and seas are expected to remain below SCA
levels thru Fri.


CA...Wind Advisory in effect until noon PDT today for zone 41. (See LAXNPWLOX).
     Wind Advisory in effect until 3 PM PDT this afternoon for
      zones 44>46-88-547. (See LAXNPWLOX).
     High Wind Warning in effect until 3 PM PDT this afternoon for
      zone 54. (See LAXNPWLOX).
     Hard Freeze Warning in effect until 9 AM PDT this morning for
      zone 59. (See LAXNPWLOX).
     Red Flag Warning in effect until 6 PM PDT this evening for
      zones 240-241-244>246-253-254-288-547-548. (See LAXRFWLOX).
PZ...Small Craft Advisory in effect until noon PDT today for zones
      650-655-676. (See LAXMWWLOX).



No significant hazards expected.





NWS LOX Office Area Forecast Discussion