Area Forecast Discussion
Issued by NWS Los Angeles, CA
Issued by NWS Los Angeles, CA
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FXUS66 KLOX 171414
AFDLOX
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
714 AM PDT Fri Apr 17 2026
UPDATED MARINE SECTION
.SYNOPSIS...17/1236 AM.
Dry and warmer weather is expected into the weekend. Gusty northeast
winds will be focused over Los Angeles and Ventura Counties today.
It should turn cooler Monday, with an increasing chance of rain
moving into the forecast area between late Monday and Wednesday.
&&
.SHORT TERM (TDY-SUN)...17/236 AM.
Mostly clear skies covered the forecast area early this morning,
save for some patches of low clouds pushing into LA County. The
main weather issue is the strong and gusty Advisory level
northerly winds over portions of the Santa Lucia and Santa Ynez
Mtns and strong and gusty NW wind along the I-5 corridor and other
portions of the the northern L.A County mtns.
These winds are expected to switch more to the N and NE after
sunrise and increase over VTU/L.A Counties as offshore pressure
gradients to the N and E increase (NAM fcst -3.8 mb LAX-DAG and
-2.2 mb LAX-BFL at 12Z). These winds will affect the usual Santa Ana
wind corridors this morning into the afternoon. Wind Advisories are
in effect for many of these areas, where wind gusts to 40 to 50 mph
will be possible, except for gusts up to 60 mph in the L.A. County
mtns. The Santa Ana winds over VTU/L.A Counties should diminish
through this afternoon. Please see the latest Non-Precipitation
Weather Message (LAXNPWLOX) for further details.
A broad NW flow aloft with H5 heights around 573 dam can be expected
today, but then an upper level ridge over the E Pac will build into
the area tonight and Sat, with H5 heights up to 574-575 dam by Sat
afternoon. The upper ridge will move off to the E Sat night and Sun
as a large upper level trof over the E Pac approaches the CA coast.
Mostly clear skies should prevail for the most part tonight thru Sat
then some increase in clouds can be expected Sat night and Sun. It
looks like some more gusty NE winds will affect the area tonight
into Sat morning as decent offshore gradients continue, but upper
level support for strong winds will be less so the winds should be
generally below Advisory levels.
Temps will increase significantly S and W of the mtns today
thanks to the offshore flow, where temps should be about 5-15 deg
above normal, while from the mtns to deserts will cool to 4-8 deg
below normal. Highs will then be 6-12 deg above normal for all
areas on Sat, then cool about 3-6 deg for Sun, especially closer
to the coast thanks to an earlier onset to the seabreeze. The
warmest day overall will be on Sat when the inland coast and vlys
are expected to reach into the 80s, with upper 80s in the western
San Fernando Vly.
.LONG TERM (MON-THU)...17/251 AM.
Still plenty of uncertainty next week with not too many changes
in the forecast from yesterday. A cold upper level low,
completely disconnected from the jet stream (also known as a cut-
off low), will slowly wobble down the West coast into the middle
of next week. Timing and exact totals still have yet to be nailed
down, which tends to be common with cut-off lows. While most
recent model runs do push the arrival of rain back about 6 hours,
there is still that 24 hours of wiggle room with the onset of rain
in any one area. As of now, the earliest time for rain is around
Monday morning along the Central Coast and Tuesday morning in LA
County. However, the recent model runs do show most of the rain
across areas south of Point Conception falling in the Tuesday
night to Wednesday morning period. There are also still about 20%
of the ensemble solutions showing little or no rain south of Pt
Conception.
Having said that, the most likely outcome is for periods of light
rain to develop across most of the area (except possibly the far
interior areas) by Tuesday afternoon with minimal impacts. The
ensemble means have been pretty steady with the amounts around a
half to one inch across SLO County (locally higher for the far NW
tip of SLO County), then dropping to mainly less than half of an
inch in LA County. However, if the upper low manages to slide all
the way down to LA County, given the time of year and the cold air
aloft, some isolated thunderstorms with heavy rain are possible
and may bring totals a little bit higher where ever the
thunderstorms form. Additionally, a few inches of snow are
possible at higher elevations in the mountains, mainly above 6000
feet.
Lastly, there is a possibility of showers lingering as late as
Thursday if the upper low takes a very slow track through the
area. This solution would also likely mean that the initial onset
of rain would be later as well. Due to the nature of cut-off
lows, it may take until late weekend before models start to come
into better agreement, and confidence increases in the forecast.
&&
.AVIATION...17/1243Z.
At 06Z at KLAX, there was no marine layer nor an inversion.
Moderate confidence in TAFs, except high confidence in KPRB,
KSMX, and KSBP.
Timing of wind changes may be off +/- 2 hours, with N-NE gusts
off by +/- 5kt at any point through the morning. Lgt to moderate
LLWS & turbulence is possible over and near mountainous terrain
through 00Z Sat, especially across Los Angeles and Ventura
counties.
There is a 40% chance of very brief MVFR cigs at KSMO, KLAX,
KLGB, KBUR, and KVNY and at some point through 17Z Fri, however,
conds may scatter and reform frequently due to the patchy nature
of the marine layer clouds.
KLAX...Moderate confidence in TAF. There is a 40% chance of very
brief BKN012-022 cigs through 17Z Fri, and conds may scatter and
reform frequently. There is a 60% chance of east wind component
reaching 7-8kts until 17Z, with a 30% chance of reaching 10 kts.
KBUR...Moderate confidence in TAF. Wind changes may be off by +/-
2 hours, with a 20% of no northerly winds through the period.
&&
.MARINE...17/713 AM.
For the Outer Waters, moderate to high confidence in current
forecast. A combination of Small Craft Advisory (SCA) level winds
and seas are expected through this morning, with a 30% chance of
lingering through tonight. Except for far northern outer waters
(PZZ670) which the Small Craft Advisory has been extended through
late tonight. Saturday through Monday afternoon, there is a
20-30% chance of SCA level winds. An approaching cold front may
bring SCA level southerly winds, along with a chance for showers
between Monday evening and Tuesday morning.
For the Inner Waters north of Point Sal, moderate to high
confidence in current forecast. Seas may flirt with SCA levels
through mid- morning across the western portion of the zone, but
are forecast to drop below advisory levels through the morning.
From late this morning through Monday, high confidence in winds
and seas remaining below SCA levels. An approaching cold front may
bring SCA level southerly winds, along with a chance for showers
between Monday evening and Tuesday morning.
For the Inner Waters south of Point Conception, moderate to high
confidence in current forecast. SCA level NE winds will develop
early this morning from Ventura south to Santa Monica and spread out
towards Anacapa Island. From Point Mugu to Malibu this morning,
there is low chance for Gale Force wind gusts nearshore below any
canyons/passes. Saturday through Monday, high confidence in winds
and seas remaining below SCA criteria for all southern Inner
Waters.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory remains in effect until 2 PM PDT this afternoon
for zones 88-354-355-358-369-371-372-374-375. (See LAXNPWLOX).
Wind Advisory remains in effect until 8 AM PDT this morning
for zone 342. (See LAXNPWLOX).
Wind Advisory in effect until 2 PM PDT this afternoon for
zones 376-378>380. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until noon PDT today for zones
650-655-670-673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...Sirard/MW/Lund
AVIATION...Lund
MARINE...DB/Lund
SYNOPSIS...Sirard
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox