FXUS66 KLOX 242046
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA 
146 PM PDT Fri May 24 2019

.SYNOPSIS...24/124 PM.

Mostly sunny skies and warmer temperatures are expected today 
with clouds developing over the mountains. A low pressure system
approaches the region on Saturday bringing cooler temperatures 
and increasing clouds. There will be a chance of rain Saturday 
night into Sunday, with a warming and drying trend early next 
week.

&&

.SHORT TERM (TDY-MON)...24/146 PM.

A weak high pressure ridge and some light offshore flow are
responsible for today's warmup and sunshine, though there are 
some cumulus buildups in the mountains and there could still be a 
few showers there through the late afternoon. We're expecting this
to be a brief reprieve in the cool/cloudy/damp conditions we've
been experiencing much of this month as another low pressure
system drops south along the coast this weekend. For Saturday
rapidly increasing onshore flow (both west/east and south/north)
and a strengthening eddy circulation will bring a return of a 
deep marine layer later tonight or Saturday morning. Some areas 
may start out clear early in the morning but clouds are expected 
to fill in all coast/valley locations within a few hours of 
sunrise with some drizzle possible especially near the foothills. 
Given the big increase in onshore flow it's questionable whether 
any clearing will occur, but if it does it will be well into the 
afternoon. This will drop highs back down into the low to mid 60s
in most areas.

At higher elevations, especially in the Ventura County Mountains
models have been consistent showing increasing instability during
the afternoon which will make conditions ripe for showers and
possible thunderstorms. The steering flow is generally parallel to
the ridges so any showers/storms that do form should remain over
the mountains and possibly the extreme western portion of the
Antelope Valley.

The upper low will drop to around Bakersfield Sunday afternoon and
into southern Nevada Sunday night. Although the trajectory is
mostly over land, there is ample pre-existing low level moisture
to interact with both the topographic and synoptic lifting forces
to generate showers over most of the area by Sunday morning and
continuing off and on most of the day. Not expecting a lot of
precip but enough to keep it pretty damp with amounts generally
a quarter inch or less but as much as a half inch to an inch in
upslope areas, especially eastern LA County where the best
orographic lift will occur. Cold air aloft will destabilize the
air mass in the afternoon and lead to a threat of thunderstorms
over the northern interior.

Conditions expected to dry out Sunday night into Monday with a
slight warming trend Monday.

.LONG TERM (TUE-FRI)...24/143 PM.

A pretty quiet weather pattern next week with temps possibly even
getting close to normal for this time of year by mid week. Doesn't
look quite as warm as it once did but still within a few degrees
of normal in most areas. Models do show a weak trough moving into
northern California Wednesday into Thursday and lingering into
Friday but with minimal impacts locally. Gradients will likely 
trend onshore which will lead to some coastal cooling and probably
a return of the marine layer at some point but otherwise dry and 
warmer than it has been the last week or so.

&&

.AVIATION...24/1851Z.

At 1659Z, there was no marine inversion at KLAX.

There were patchy low clouds across SLO/northern SBA Counties and
the mtns of L.A./VTU Counties. Conds were mostly VFR and clouds 
should remain scattered in most areas through the day. Expect 
widespread low clouds in all coastal and valley areas tonight, 
with generally MVFR conds expected. 

KLAX...Moderate to high confidence in 18Z TAF. There is a 20-30% 
chance that marine clouds will arrive plus or minus two or more 
hours from the forecasted time. There is a 20-30 percent chance of
east winds greater than 7 knots.

KBUR...Moderate to high confidence in 12Z TAF. There is a 20-30% 
chance that marine clouds will arrive plus or minus two or more 
hours from the forecasted time.

&&

.MARINE...24/108 PM.

For the outer waters, fairly low confidence in forecast. Winds 
may get close to Small Craft Advisory (SCA) levels this afternoon 
and evening. There is a 40% chance that a SCA will be needed, 
especially across the northern zone (PZZ670). This will also be 
true for Sat afternoon. SCA conds are expected for the northern 
outer waters zone Sat night thru Sun night, while there is a 40% 
chance of SCA level winds across the remainder of the outer 
waters. SCA winds are expected across all outer waters Mon thru 
Tue.

For the inner waters north of Pt Sal, moderate confidence in 
forecast. Conds are expected to remain below SCA levels thru Mon 
morning. However, there is a 30% chance of SCA level winds during
the afternoon/evening hours today thru Sun. SCA conds are 
expected Mon thru Tue. 

For the inner waters south of Pt Conception, high confidence in 
forecast. Through Sun morning, winds and seas will remain below 
SCA levels. From Sun afternoon thru Tue, there is a 30-40% chance
of SCA level winds across the western half of the Santa Barbara 
Channel and the western portion of the southern inner waters.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

.HAZARD POTENTIAL OUTLOOK (MON-FRI).

No significant hazards expected.

&&

$$

PUBLIC...MW
AVIATION...Sweet/DB
MARINE...Sweet
SYNOPSIS...Stewart

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