657
FXUS66 KLOX 180541
AFDLOX
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
941 PM PST Mon Nov 17 2025
.SYNOPSIS...17/451 PM.
A cooler storm system will continue to spread rain across the
area through tonight, mainly across Ventura and Los Angeles
Counties. Lingering showers may continue into Tuesday. Wednesday
will offer a brief respite from the rain with warmer temperatures.
Another storms is slated to arrive next Thursday and linger into
Friday.
&&
.SHORT TERM (MON-THU)...17/811 PM.
***UPDATE***
Another wet day as a cold front marched through the area. The
front is currently over the eastern portion of la county and sill
push out by 10 pm. The front dropped between a half inch and inch
of rain across the flatter portions of the csts/vlys while the
coastal slopes saw 1 to 2 inches. Rainfall rates during the peak
of the event was enough to warrant flash flood warnings.
Snow levels started out at 7000 ft this morning but have fallen to
5000 ft and snow has been reported throughout the mtns. Snow
levels could fall to as low as 4000 ft by Tuesday morning with
some non accumulating snow possible on the Grapevine. A winter
weather advisory is out the mtns due to 2 to 5 inches of snowfall
gusty winds and dense fog.
Most of the csts/vlys struggled to even get out of the 50s today.
The notable exception was the LA cst and San Gabriel Vly where the
later arriving rain allowed temps to reach the mid 60s. Most max
temps ended up 8 to 12 degrees blo normals today.
While the front will no longer be in the area tonight and Tuesday
to cold core of the upper will be. This will bring enough
instability to the area for a slight chc of TSTM development.
The forecast was updated for chc of precip, clouds and thunder.
***From Previous Discussion***
Overall, 12Z models in good synoptic agreement through the period.
Main issues will be upper low passing across the area, bringing
another round of precipitation to the area. The low drop southward
across Point Conception tonight/Tuesday before moving east across
far Southern California Wednesday and Thursday.
RAIN...
Cold front is currently moving across Ventura county and will move
into LA county later this afternoon. In association with the
front, light to moderate rainfall can be expected, generating a
majority of the widespread measurable rainfall. Behind the front
tonight and Tuesday, an unstable and showery pattern will prevail
as the upper low drops southward. By Tuesday evening, rainfall
totals with this system are expected to range from 0.50-1.00
inches for coastal/valley areas with 1-2 inches for the foothills
and mountains. Rainfall rates through Tuesday are expected to
generally be under 0.50 inches per hour and will generate nuisance
flooding across the area. However, the latest high resolution RRFS
and HRRR indicate the potential for rain rates around 1.00 inch
per hour along the front this afternoon across Ventura and
especially LA counties. If these rates does come to fruition,
there could be some significant debris flows across the burn
scars, including the Palisades and Eaton Scars.
After a dry day on Wednesday, another system will impact the area
on Thursday. At this time, rain looks to begin across the Central
Coast Thursday morning, working its way south into LA county by
Thursday afternoon/evening. By Thursday evening, rainfall totals
will generally range between 0.25 and 0.75 inches.
SNOW...
Based on latest guidance, current snow levels are around 7000
feet, but will drop to around 5000 feet tonight and on Tuesday.
The bulk of the rainfall will fall before the snow levels drop.
However, there still should be some decent accumulations across
the northern Ventura mountains and the eastern San Gabriel
Mountains (5-10 inches above 7000 feet and 2-5 inches between 5000
and 7000 feet). So, have issued a WINTER WEATHER ADVISORY for
these areas through 1000 PM Tuesday.
As for the Grapevine area, there is a chance of a dusting of snow
Tuesday morning as the snow levels lower.
Anyone traveling through the mountains through Tuesday should be
ready for winter weather conditions.
THUNDERSTORMS...
Along with the rain and snow, thunderstorms will be a risk for
the through Tuesday. As the upper low drops southward today, a
cold and unstable air mass will bring a threat of thunderstorms
to all areas. On Tuesday, the threat of thunderstorms looks to be
confined to LA county as well as interior sections of Ventura and
Santa Barbara counties.
Any thunderstorms that develop will be capable of producing
frequent lightning and gusty/erratic winds. Additionally, any
storms could produce significant rainfall rates, likely exceeding
the sub-hourly USGS thresholds, and could generate significant
debris flows in and around the recent burn scars.
If you live near a burn scar, be prepared for significant rainfall
and potential debris flows. Pay attention to local emergency
officials for any actions to take if conditions do deteriorate.
.LONG TERM (FRI-MON)...17/107 PM.
For the extended, models continue to exhibit decent synoptic
agreement through the period. Main feature of note will be upper
low that will impact the area Friday and Saturday.
On Friday, this upper low will drop southward, southwest of San
Nicolas Island and will move eastward into northern Baja Mexico on
Saturday and Sunday. With this pattern, the threat of rain will
continue for all areas on Friday, but will diminish from north to
south through the day with a lingering slight chance of showers on
Saturday south of Point Conception. With this system from Thursday
through Saturday, rainfall totals are expected to range from 0.25
to 0.75 inches across coastal and valley areas with up to around
1.25 inches across the foothills and mountains. However, given
the nature of upper lows, there is the potential for rainfall
totals to be a bit higher than currently forecast. Snow levels
look to drop to around 5500 feet on Friday/Saturday which could
result in several inches of additional snowfall.
On Sunday, the low will move eastward. This will bring some
welcome dry conditions to the area.
&&
.AVIATION...18/0540Z.
At 0445Z at KLAX, there was no marine layer. There was a moist
layer extending to 6000 ft.
Moderate confidence in TAFs. There is a 30 percent chc of no MVFR
cigs developing overnight at any given site. If cigs do form there
is 30 percent chc that there will be IFR cigs.
There is a 10 percent chc of a TSTM at KSMO, KLAX and KLGB after
20Z-02Z.
KLAX...Moderate confidence in TAF. There is a 30 percent chc of
no MVFR cigs developing. If cigs do form there is 30 percent chc
that they will be BKN008. There is a 10 percent chc of a TSTM
20Z-02Z. There is a 25 percent chc of an 9 kt east wind component
09Z-16Z.
KBUR...Moderate confidence in TAF. There is a 30 percent chc of
no MVFR cigs developing. If cigs do form there is 30 percent chc
that they will be BKN008. There is a 30 percent chc of bkn040-050
conds 18Z-02Z.
&&
.MARINE...17/822 PM.
For the waters from southwest through northwest of the Channel
outside the southern California bight and the nearshore waters
along the Central Coast, Small Craft Advisory (SCA) level winds
continue through tonight. SCA seas will persist through mid-day
Tuesday. Winds and seas will likely fall below SCA levels for
Wednesday and Thursday, then there is a moderate to high (30-50
percent) chance of SCA conditions developing on Friday.
Inside the Southern California Bight, SCA level winds will
continue through tonight, with a chance to linger into the early
morning hours. Conditions will likely remain below SCA levels for
Wednesday and Thursday, then there is a moderate- to- high (30-50
percent) chance of SCA conditions developing on Friday.
There is a 10-20 percent chance of thunderstorms across the
coastal waters through late Tuesday morning. Any thunderstorms
that develop will be capable of producing brief heavy rain, small
hail, dangerous cloud to surface lightning, gusty and erratic
winds, locally rough seas, and possible waterspouts.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect until 10 AM PST Tuesday for
zones 340-346. (See LAXCFWLOX).
Winter Weather Advisory remains in effect until 10 PM PST
Tuesday for zones 377-380. (See LAXWSWLOX).
PZ...Small Craft Advisory in effect until 3 AM PST Tuesday for
zones 645-650-655. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 PM PST Tuesday for
zones 670-673. (See LAXMWWLOX).
Small Craft Advisory in effect until 9 PM PST Tuesday for
zone 676. (See LAXMWWLOX).
&&
$$
PUBLIC...Thompson/Rorke
AVIATION...Rorke
MARINE...Ciliberti
SYNOPSIS...Smith
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox
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