Crystalaire, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

598
FXUS66 KLOX 261258
AFDLOX

Area Forecast Discussion...CORRECTED
National Weather Service Los Angeles/Oxnard CA
558 AM PDT Sat Apr 26 2025

.SYNOPSIS...26/436 AM.

An upper low and frontal system will bring rain to the area today
with snow above 4500 or 5000 feet. High temperatures today will
be 10 to 25 degrees below normal. Dry weather is expected Sunday
through next week. There will be a warming trend Sunday through
Tuesday, with highs possibly rising to slightly above normal
levels Tuesday. Some cooling is expected Wednesday, with minor
changes for the end of the week.

&&

.SHORT TERM (TDY-MON)...26/500 AM.

A cold but compact upper low was centered about 200 NM west of
Point Conception early this morning, with a surface low just to
its east. A frontal system, which extended eastward then arced
southward from this surface low, was beginning to spread rain into
the Central Coast. On satellite, this system looked fairly
impressive, with a comma head extending to the north and west of
the upper low.

Since the front was beginning to pivot into a northwest to
southeast orientation, there will be less time than usual between
the onset of rain in SLO County and the onset of rain in L.A.
County. Rain will overspread SLO/SBA Counties by sunrise, push
into Ventura County early this morning, then into L.A. County by
mid to late morning. Expect a 3 to 5 hour period of steady light
to moderate rain, with some briefly heavy rain, followed by
numerous showers. There was some instability with the front,
especially near the center of the low. Therefore, there is a
slight chance of thunderstorms this morning into this afternoon,
mainly across SLO and SBA Counties and in the mtns of northern VTU
County and northwestern L.A. County. Rainfall rates should be
mostly less than two tenths of an inch per hour, but there is a
chance of rates over a third of an inch per hour in heavier
convective showers or thunderstorms. Showers should end across SLO
and SBA Counties by sunset, and across L.A. County before
midnight.

In general, rainfall totals should average one third to two thirds
of an inch in most areas, with local totals up to an inch possible,
mainly from the mtns of southern SBA County thru northern VTU
County and into the San Gabriel mtns in L.A. County. Snow levels
will be between 4500 and 5500 feet. Snow accumulations will likely
total 3 to 6 inches of above 5000 or 5500 feet, with local totals
to 8 inches. Snow accumulations of 2 to 5 inches are likely down
to 4500 feet, except down to 4000 feet in SBA County. There could
be some slushy snow accumulation on higher portions of Interstate
5 near the Grapevine, but since it is late April, the roads may
be too warm for significant snow to stick. Still, anyone traveling
into the mtns today or tonight should be prepared for dangerous
and slippery driving conditions.

There could be a few breaks of sunshine late in the day, mainly
north of Point Conception, but overall it will be a rather gloomy
day. High temps will average 10 to 20 degrees below normal for
late April in most areas, with some locations up to 25 degrees
below normal. In fact, some record daily low maximum temperatures
may be recorded today.

The upper low will lift northeastward across Nevada tonight and
into northern Utah on Sun. Skies will likely be partly cloudy
across the area Sun, and any wraparound showers should remain
north and east of the region. Gusty northwest winds will affect
the Central Coast and southern SBA County Sun afternoon and
evening, but winds should remain below advisory levels. In the
Antelope Valley, strong west winds may reach advisory levels. With
the height rises, sunshine, and some increase in northerly
gradients, there should be significant warming in most areas Sun,
though max temps will likely still be below normal.

A vort max dropping southward on the western side of the upper
low will keep a general trough in place across the forecast area
Sun night/Mon. However, rising heights and plenty of sunshine
should result in several more degrees of warming Mon, especially
away from the beaches. In fact, by Mon max temps may get back to
close to normal levels for this time of year.

.LONG TERM (TUE-FRI)...26/508 AM.

An upper ridge will build into the region from the Pacific Tue,
and the warming trend will continue, Max temps may rise to
slightly above normal levels, especially away from the coast. High
temps could reach 80 degrees in the warmer valleys, and in the
Antelope Valley, with temps mostly in the mid 60s to mid 70s on
the coastal plain and in the mountains. The ridge will be short-
lived, and a weak trough will move into the region on Wed. This
will likely bring a return of night thru morning low clouds to
coastal and some valley areas, along with some cooling west of the
mtns. Models show a weak trough or upper low lingering across the
area for Thu and Fri, with night thru morning low clouds in
coastal and valley areas, and max temps likely a bit below normal.

&&

.AVIATION...26/1257Z.

At 0802Z at KLAX, the marine layer was around 5800 ft deep. The
top of the inversion was at 7000 ft with a temperature of 0 C.

Good confidence in TAFs for KPMD and KWJF.

Moderate confidence in the remainder of TAFs. Expect MVFR conds
with SHRA/RA, and potential for IFR conds under heavier precip.
Timing of precip may be off +/- 2 hours. Behind main rainband,
expect spotty showers under ULL for central coast sites after
06Z Sun.

KLAX...Moderate confidence in 12Z TAF. Rain could start as early
as 14Z or as late as 16Z. Cig and Vis may vary between BKN020 and
BKN035 and 3SM and 6SM during rain. There is a 30% chance of IFR
conds as main precip band moves through around 15Z Sat.

Low confidence in winds from 12Z to 18Z Sun. Some guidance suggest
winds will be light and variable from 12Z to 15Z, with more
confidence in a west wind after 15Z. However, there is a 25%
chance of east wind component exceeding 6 kts from 12Z to 15Z.

KBUR...Moderate confidence in 12Z TAF. Cig and Vis may vary
between BKN020 and BKN035 and 3SM and 6SM during rain. There is a
30% chance of IFR conds as main precip band moves through around
15Z Sat.

&&

.MARINE...26/428 AM.

Overall, moderate confidence in forecast.

For the Outer Waters, there is a 30% chance of SCA level wind
gusts for western portions of PZZ676 during afternoon/eve hours on
Sat. Widespread chances for SCA conds increase (60-90%) Sun
afternoon thru Tues night.

For the Inner Waters north of Point Sal, conditions are expected
to remain below SCA Criteria through Sat. Potential for widespread
SCA winds during the afternoon/eve hours Sun thru Tues (50-80%
chance).

For the Inner Waters south of Point Conception, high confidence in
conds remaining below SCA levels through Sat morning. There is a
30% chance of SCA level winds across the Santa Barbara Channel
during the afternoon/eve hours on Sat. Thereafter, chances
increase to >80% across the SBA Channel and 50-60% for southern
Inner Waters off the LA and OC coasts on Sunday, including
nearshore. There is a 50-60% chance of SCA level winds for
western portions of SBA Channel Mon afternoon/eve. Much lower
chances Tue through Wed.

Across the waters, rain is forecast to impact the waters through
at least Sat night. There is a low chance of thunderstorms (10%)
Sat over the Inner and Outer Waters along the Central Coast. Any
thunderstorm could produce gusty, erratic winds, lightning, and
small hail. Seas are generally expected to remain below SCA
levels through the work week. However, seas could approach SCA
Criteria at times across far western portions of the Outer Waters
through Wednesday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Winter Weather Advisory now in effect until 7 PM PDT this
      evening for zones 353-376-377. (See LAXWSWLOX).
     Winter Weather Advisory remains in effect from 9 AM this
      morning to 11 PM PDT this evening for zones 378>380. (See LAXWSWLOX).
PZ...NONE.

&&

$$

PUBLIC...DB
AVIATION...Black
MARINE...Smith/Black
SYNOPSIS...DB

weather.gov/losangeles

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