West Covina, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

016
FXUS66 KLOX 122133
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
233 PM PDT Mon May 12 2025

.SYNOPSIS...12/231 PM.

Cool and windy conditions will prevail through Tuesday with a
gradual warm up and generally lighter onshore winds through
Friday.

&&

.SHORT TERM (TDY-THU)...12/225 PM.

High confidence that a relatively strong trough for this time of
year will continue to drop into California through Tuesday before
departing, leading to remnant weak troughing and northwest flow
aloft.

The main impacts of this system will be the wind with advisory
level onshore to northwest winds continuing for southern Santa
Barbara County and coastal Ventura County as well as the Antelope
Valley into this evening where Wind Advisories are in effect.
There is a 20 percent chance that advisory level winds may
continue overnight for interior mountains and deserts prone to
northwest winds.

Northwest flow across the region will likely spin up an eddy with
low clouds and drizzle down south again tonight into Tuesday
morning. However, the northward extent is in question, so we have
the highest confidence in low clouds with drizzle at times for
much of Los Angeles County, we have lower confidence for Ventura
County.

Rising 500 mb heights will support a warm up Wednesday into
Thursday (highs generally 68-82 by Thursday, coolest near the
coast), focused inland of a shallower marine layer where clouds
may seasonally slow to clear each day. Weaker but still present
Sundowner and inland onshore winds will peak each afternoon to
evening, but should mostly be below advisory levels.

.LONG TERM (FRI-MON)...12/225 PM.

Below normal confidence for Friday through early next week with
near equal odds of a repeat pattern like we are expected to
experience through Tuesday or weaker northwest flow aloft more
akin to what Wednesday/Thursday time frame look like with similar
impacts possible. The repeat performance would be windier, colder,
with drizzle or light showers, while the latter would be somewhat
warmer, drier, with less wind. Either way significant impacts
seem unlikely during this timeframe.

&&

.AVIATION...12/1637Z.

At 16Z over KLAX, the marine layer was 2400 ft deep. The top of
the inversion was 4300 feet with a temperature of 14 Celsius.

There is a 10% chance of a light shower at KPRB KSBP 18-22Z today.
Otherwise, High confidence in VFR at KPRB, KSBA, KPMD, KWJF
through Tuesday. High confidence that any airport currently with
MVFR ceilings will clear by 20Z. High confidence that any
ceilings that form tonight into Tuesday will be MVFR or VFR. Low
confidence on ceiling coverage or timing however, and will likely
be stratocu with patches of clearing instead of a solid blanket of
clouds.

High confidence in stronger than usual onshore winds 21-04Z today,
with gusts over 25 knots likely at all coastal and desert
airports. Brief LLWS possible 18-20Z as the winds start shifting
and increasing.

KLAX....High confidence in VFR conditions by 20Z. Low confidence
on timing of ceiling return tonight, but high confidence in MVFR
or VFR ceilings. Current southeast winds are honestly surprising
at how strong and prevalent they are. Best estimate is for the
winds to flip to onshore 1730-1830Z. West gusts 25-30 knots likely
21-03Z today. Another round of E-SE winds are likely tomorrow
13-17Z, with a moderate risk of 10+ knots.

KBUR...High confidence in VFR conditions by 20Z. Low confidence
on timing of ceiling return tonight, but high confidence in MVFR
or VFR ceilings.

&&

.MARINE...12/221 PM.

Winds are slower than expected in developing, but still expected
to ramp up through this afternoon. Steep seas with widespread
winds of 25 to 35 knots will be building through Tuesday, with
generally hazardous conditions for most vessels each afternoon and
evening. Current Small Craft Advisories and Gale Warnings look
good. While some areas will see some lulls, steep seas will affect
much of the area.

Moderate confidence in forecast for the next 3 days...winds plus
or minus 5 knots and seas plus or minus 3 feet.

Gale Watch remains for waters south of Point Sal for Tuesday,
including the Santa Barbara Channel (west and east portions). 60%
chance of a lower-end Gale Warning needed. Decided to keep it a
watch as the winds are slow to develop today which adds some
uncertainty to tomorrow.

High confidence in improving winds and seas (heights remain
elevated but periods lengthen) Wednesday through Friday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory now in effect until 9 AM PDT Tuesday for zones
      349-351-352. (See LAXNPWLOX).
     Wind Advisory in effect until 9 PM PDT this evening for zones
      350-354. (See LAXNPWLOX).
     Wind Advisory remains in effect until 9 PM PDT this evening
      for zones 381>383. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Wednesday for
      zones 645-655-670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PDT this afternoon
      for zone 650. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Tuesday for zone 650. (See LAXMWWLOX).
     Gale Watch in effect from Tuesday afternoon through Tuesday
      evening for zones 650-673-676. (See LAXMWWLOX).
     Small Craft Advisory in effect until 2 PM PDT Tuesday for
      zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Munroe
AVIATION...Kittell
MARINE...Kittell
SYNOPSIS...Munroe

weather.gov/losangeles

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