Monrovia, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

407
FXUS66 KLOX 072005
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
105 PM PDT Mon Apr 7 2025

.SYNOPSIS...07/1218 PM.

Dry weather is expected across Southwest California through at
least the weekend and likely beyond. It will be cooler today,
then a gradual warming trend will start Tuesday and continue
through Thursday. Well above normal temperatures are likely
Wednesday and Thursday with highs in the mid 80s to low 90s across
the valleys. It will turn cooler Friday and Saturday as onshore
flow increases.

&&

.SHORT TERM (TDY-THU)...07/1237 PM.

A trough moving through the Pac NW today has knocked the ridge
down enough to turn gradients onshore and cool things off 4-8
degrees from yesterday in all areas except mountains and Antelope
Valley. In addition, patches of dense fog continue to lurk across
the coastal waters. Expecting one more day of relatively mild
weather and areas of coastal fog before high pressure returns Wed
and Thu, weakening the onshore flow and boosting temperatures.
Locally gusty north winds will continue each evening across
southwest Santa Barbara County and the Grapevine region, mostly
below advisory levels.

For Wed and Thu, still expecting warmer valley highs to reach at
least the lower 90s and about a 50-60% chance of mid 90s in
Woodland Hills, likely warmest on Thu. This puts inland areas
10-15 degrees above normal and coastal areas (mostly 70s) around
5 degrees above normal. Far inland coastal areas like Downtown LA
should be in the low to mid 80s. Records are mostly in the mid
90s so it will be close in the warmest valleys but not likely
elsewhere. For now am holding off issuing any heat risk hazards.

.LONG TERM (FRI-MON)...07/1247 PM.

High pressure starts to get knocked down Friday as the next
Pacific trough arrives. Still a warm day inland Friday with
widespread 80s in the valleys but an earlier sea breeze will bring
temps down at least 3-6 degrees from Thursday. Then 1-3 degrees of
cooling each day over the weekend into early next week as models
are in good agreement showing a weak and slow moving upper low
developing near 30n/125w, by which time all areas except the
higher mountains and Antelope Valley will be at least few degrees
below normal. Expect increasing low clouds and fog along the coast
and likely well into the valleys as well as onshore LAX/DAG gradients
increase to over 9mb.

&&

.AVIATION...07/1724Z.

At 17Z over KLAX, the marine layer was 300 feet deep with an
inversion top at 2800 ft and 16 degrees Celsius.

High confidence in onshore winds being dominant, with seasonal
wind speeds similar to yesterday.

High confidence in VFR conditions at all airports through 02Z
today. From 02Z through Tuesday, high confidence in VFR
conditions continuing over KBUR, KVNY, KPMD, KWJF. Low confidence
elsewhere, with chances for LIFR/IFR conditions at KPRB (20%)
KSBP (20%) KSMX (70%) KSBA (10%) KOXR (20%) KCMA (10%) KSMO (30%)
KLAX (40%) KLGB (60%).

KLAX...High confidence in VFR conditions through 03Z. 40% chance
of ceilings forming as early 03Z and as late as 15Z, with 13Z
having the highest chances. If ceilings form, LIFR most likely
category, with a optimistic chance of IFR. SE winds will form in
the morning hours, but unlikely to exceed 8 knots.

KBUR...High confidence in VFR conditions through at least Tuesday
with seasonal onshore winds.

&&

.MARINE...07/921 AM.

A shallow marine layer will bring a risk of dense fog nearly
anywhere through most of the week, with the highest chances off
the Central Coast, Los Angeles County Coast, and Orange County
Coast.

Small Craft Advisory (SCA) winds (21+ knots) and/or seas (of 10+
feet) certain for the waters beyond 20 miles from shore this
afternoon through Tuesday, and likely through at least Thursday.

For the nearshore Central Coast and western Santa Barbara Channel,
there is a 70% chance of reaching SCA winds each afternoon and
evening through at least Tuesday. High confidence in conditions
staying under SCA elsewhere.

All areas will see short period choppy seas on top of the long
period swell due to these winds, largest in the late afternoon and
evening hours.

&&

.BEACHES...07/923 AM.

A long period (14-17 seconds) west to northwest swell will peak
this morning then slowly subside through Tuesday. The current High
Surf Advisories will stay in effect through 3am Tuesday. The
Central Coast may need to be extended deeper into the morning with
the latest buoy reports running 1-2 feet over projections.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect until 3 AM PDT Tuesday for zones
      340-346-354. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 9 PM PDT this evening
      for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Tuesday for
      zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Wednesday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...MW
AVIATION...RK
MARINE...Kittell
BEACHES...RK
SYNOPSIS...MW

weather.gov/losangeles

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