813
FXUS66 KLOX 172016
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
116 PM PDT Fri Jul 17 2026

.SYNOPSIS...17/105 PM.

Minimal changes expected over the next few days in the way of
temperatures. Morning low clouds and fog will return to many
coastal areas each day through early next week. A warming trend is
expected by the middle of next week as upper level high pressure
builds into the area while onshore gradients weaken.

&&

.SHORT TERM (TDY-MON)...17/1224 PM.

Not much change in the upper level pattern over srn CA thru Sun
with the region under the SW periphery of a large western U.S.
upper level high centered mainly between WY and CO. H5 heights
over the forecast area will be generally in the 589-591 dam range
thru the period. The upper level flow will start out mostly
southerly thru Sat then turn more SE into Sun. Some monsoonal
moisture will push back into SW CA this weekend with an increase
mid level clouds at times, and by Sun some afternoon cu buildups
cannot be ruled out in the mtns along with a non-zero chance
(5-10%) of a shower or thunderstorm focsued in the VTU/L.A. County
mtns with about a 5 percent of a shower just about anywhere
tonight. Even so, it looks like the bulk of the monsoonal moisture
will remain east of L.A. County thru Sun. A rapidly weakening
tropical cyclone will past well to the west Sunday into Monday and
may provide a bump in moisture across the region including the
Central Coast being closest to the system. The most likely
scenario is a bump up in mid to high clouds especially for
northern areas, however, there is a 5-10 percent chance of a
shower or thunderstorm, especially into Monday.

Pressure gradients will be onshore and increase over the next
couple of days. This will support near normal temperatures along
with an increase in coastal night and morning low clouds and fog.
Afternoon highs should range from the 70s to low 80s for the
coast, mid 80s to mid 90s for the vlys and lower mtns, and 90s to
around 100 for the deserts.

.LONG TERM (TUE-FRI)...17/1224 PM.

The large western U.S upper level high center is forecast to
drift S from Colorado on Mon to the area around New Mexico and the
northern Texas panhandle by Thu. Southwestern CA will continue to
be on the western periphery of this large upper level high, with
H5 heights slowly increasing to 592-594 dam during the extended
period.

The flow aloft will mostly be from the SE with monsoonal moisture
expected to continue to push into the area. Precipitable water
values are forecast to be in the 1.25 to 1.40 inch range for the
most part which is about 150 to 160 percent of normal for this
time of year. Although the deepest moisture and instability is
forecast to remain east of L.A. County during the extended period,
it does look like the best chance of afternoon convection will
come Wednesday and Thursday over the mountains. For now, there is
only a minimal chance of showers late Thu in the fcst for the
eastern L.A. County mtns. Otherwise, there is a non-zero chance
(10%) for a thunderstorm to develop in the mtns especially Wed and
Thu. As we draw closer to early next week, we should have a
better idea of the chance and extent of afternoon convection for
the middle of next week.

Otherwise, it look like varying amounts of night and morning
coastal low clouds and fog will prevail during the extended
period, with a warming trend thru the middle of next week.
Moderate to high heat risk may expand into Wednesday or Thursday
as pressure gradients weaken and maybe turn lightly offshore in
the mornings with the potential for 500 mb heights building to
594-596. There is a moderate (50-60 percent chance) that at least
Heat Advisories will be needed in some areas, including potential
near the coast.

&&

.AVIATION...17/1736Z.

At 1700Z at KLAX, the marine layer was 2000 ft deep. The top of
the inversion was at 4500 ft with a max temperature of 23 C.

High confidence in VFR TAFs for KPMD and KWJF.

Low confidence KPRB, KBUR, and KVNY. There is a 30% chance for
IFR conds at KPRB after 10Z. There is a chance VFR conds prevail
at KBUR (40%) and KVNY (50%). If cigs do arrive, lower confidence
in timing of cig which could be up to 4 hours earlier than
forecast, and min cig height may be off by +/- 300 feet.

Moderate confidence in remaining TAFs. Cigs expected at each site,
except for a 25% chance no low clouds at KSBP tonight. Flight cat
changes may be off by 3 hours, with lowest confidence in time for
KSBP and KSBA. Min cig heights may be off by +/- 200 feet.

KLAX...Moderate confidence in TAF. Arrival of cigs may be as early
as early as 01Z or as late as 06Z. 10% chance for brief
OVC008-009 cigs before 10Z. 30% chance of an east wind component
reaching 6 kt overnight into Sat morning.

KBUR...Low confidence in TAF after 06Z. 40% chance VFR conds
prevail. If cigs do arrive, lower confidence in timing of cig
which could be up to 4 hours earlier than forecast, and min cig
height may be off by +/- 300 feet.

&&

.MARINE...17/105 PM.

Marginal Small Craft Advisory (SCA) northwest winds (20-25 kt)
and seas will impact the waters beyond 20 NM from shore (except
for nearshore along the Central Coast) through tonight. Localized
gusts to 25 kt may occur in the far western portion of the Santa
Barbara Channel through this evening. Then conditions are
expected to remain below SCA levels through Monday except for
fairly localized SCA level northwest wind gusts across the Outer
Waters more than 20 NM from shore. Northwest winds will begin to
strengthen Tueday and SCA conditions are expected to occur much of
next week.

A series of moderate period southerly swell will impact the
waters late Sunday through much of next week which may impact
south facing harbors, including the Port San Luis area.

&&

.BEACHES...17/105 PM.

Over the eastern Pacific, Tropical storm Elida is forecast to
strengthen to hurricane status tomorrow. It is then expected to
move to the north and west well off the Baja coast. Another
tropical disturbance is expected to strengthen next week and
generally follow the path of Elida to the northwest. Both systems
will produce moderate period southerly swells. High Surf
Advisories and Beach Hazards Statements have been issued across
Southwest California from Sunday evening through Tuesday night.
The secondary system on the heels of Elida and an incoming long
period southern hemisphere south swell forecast to arrive sometime
late next week will likely contribute to continued and
potentially more hazardous beach conditions into the following
weekend. Additional High Surf Advisories and/or Beach Hazards
Statements are likely next week.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect from 5 PM Sunday to 11 PM PDT
      Tuesday for zones 87-354-362-366. (See LAXCFWLOX).
     Beach Hazards Statement in effect from Sunday afternoon
      through Tuesday evening for zones 340-346. (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 Saturday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Munroe/Sirard
AVIATION...Lewis
MARINE...Lewis
BEACHES...Lewis
SYNOPSIS...Lewis

weather.gov/losangeles

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