Winter Storm in California, March 5 to 7, 2025

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
525 PM PST Wed Mar 5 2025

.SYNOPSIS...05/153 PM.

A storm system will bring periods of rain and mountain snow today
and Thursday with some gusty winds. Dry and warmer weather
expected Friday through the weekend, then another series of storm
systems will bring more rain and mountain snow to the region next
week.

&&

.SHORT TERM (TDY-SAT)...05/114 PM.

Today's storm performed as expected with just light rain with
high snow levels (>8000 feet). Rain totals as of 1pm have been
under a quarter inch in most areas south of Pt Conception and a
quarter to half inch north.

Part 2 of this storm tonight and tomorrow is much colder with
snow levels falling rapidly to 3500 feet or so. However, unlike
today with steady light rain for several hours, tomorrow's precip
will be much more showery with some areas getting little to no
precip and others getting brief periods of moderate to locally
heavy rain. And there likely will be periods of sunshine in
between showers. Thunderstorm chances are still quite low with the
best chance of those in SLO and northern Santa Barbara County
where the most unstable air will be. So rain amounts Thursday will
be extremely variable, however hi res model ensembles indicate
the chances for rain rates reaching debris flow thresholds are
below 5% at this time. As mentioned, any heavier downpours
Thursday are expected to be brief with the steering flow close to
30 mph from the west keeping the showers moving at a quick pace.

With the lowering snow levels there will be concerns for travel
delays over the mountain roads, including Interstate 5 over the
Grapevine Thursday into Thursday night. Accumulations in most
areas expected to be under 6 inches (Grapevine under 3") but the
higher mountains near the LA/San Bernardino border could get close
to a foot of snow. Gusty westerly winds expected later Thursday
into Thursday evening, especially near the coast.

There's a chance of some lingering showers Friday morning,
especially north facing mountain slopes and the eastern San
Gabriels. Otherwise, a warming and drying trend will begin that
will continue through the weekend.

.LONG TERM (SUN-WED)...05/152 PM.

An active weather pattern is expected to return next week with at
least two storms coming through the area. The first one is
expected Monday afternoon into Tuesday, followed by a second one
Wednesday into Thursday. Still a fair amount of uncertainty on the
specific timing, especially since the first system is mostly
cutoff from the jet stream which remains over the Pac NW. However,
ensemble solutions have been fairly consistent with timing (give
or take 12-18 hours) as well as amounts. There are some
indications of a low end AR component, mainly with the second
system. Rain amounts next week are expected to be higher, and
possibly much higher in some areas. Currently the ensembles are
indicating the second system being slightly stronger than the
first, but that could change as we get closer. At a minimum, most
areas should get an additional inch of rain between the two
systems with a potential for as much as 2-4 inches, especially in
upslope areas and northwest SLO County. And several inches of snow
possible in the mountains above 6000 feet.

&&

.AVIATION...06/0124Z.

At 0030Z at KLAX, there was a deep moist layer up to 5000 ft.

Low to moderate confidence in TAFs. Isolated to scattered showers
will continue through the period, bringing variable cigs with
generally IFR to MVFR conds during periods of rain, and during
heavier showers LIFR conds. The timing of flight cat changes may
be off +/- 1 to 3 hours.

There is a 10% chance of isolated tstorms for all sites through
the period, increasing to a 20% chance for KPRB, KSBP, and KSMX
after 15Z. Any thunderstorm that forms may bring locally gusty and
erratic winds, dangerous cloud to surface lightning, and/or small
hail.

KLAX...Low to moderate confidence in TAF. Isolated-scattered
showers will continue through 00Z Fri, and cigs may bounce between
BKN008-025 during showers, with BKN004 at times of heavier showers.
The timing of flight cat changes may be off +/- 1 to 3 hours.
There is a 10% chance of isolated tstorms through 00Z Fri, which
could bring locally gusty and erratic winds, dangerous lightning,
and or/small hail. Good confidence in E wind component remaining
under 8 kt through the period.

KBUR....Low to moderate confidence in TAF. Isolated-scattered
showers will continue through 00Z Fri, and cigs may bounce between
BKN008-025 during showers, with BKN004 at times of heavier showers.
The timing of flight cat changes may be off +/- 1 to 3 hours.
There is a 10% chance of isolated tstorms through 00Z Fri, which
could bring locally gusty and erratic winds, dangerous lightning,
and or/small hail. Good confidence in E wind component remaining
under 8 kt through the period.

&&

.MARINE...05/1253 PM.

Small Craft Advisory (SCA) level W-NW winds are expected to form
across most of the waters later this afternoon into early this
evening then continue much of the time thru Fri night. However in
the southern inner waters zone (PZZ655), SCA conds are expected
thru Fri afternoon and for the inner waters N of Pt. Sal (PZZ645),
SCA conds are expected thru late Thu night, with a 30%-40% chance
of SCA conds Fri afternoon/eve.

In addition, local gale force wind gusts are possible (30%-40%
chance) across the southern inner waters tonight.

Seas will be hazardous and steep across much of the waters
tonight thru Fri night.

Conds should then be below SCA levels for all the coastal waters
Sat thru Mon night.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Winter Weather Advisory remains in effect until 7 AM PST
      Friday for zones 353-376>379. (See LAXWSWLOX).
     Winter Storm Warning in effect until 7 AM PST Friday for zone
      380. (See LAXWSWLOX).
PZ...Small Craft Advisory in effect until 3 AM PST Friday for zone
      645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PST Saturday for
      zones 650-670-673-676. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PST Friday for zone
      655. (See LAXMWWLOX).

&&

PUBLIC...MW
AVIATION...Lund
MARINE...Sirard
SYNOPSIS...MW

weather.gov/losangeles

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