Area Forecast Discussion
Issued by NWS Los Angeles, CA

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FXUS66 KLOX 251000

300 AM PDT Mon Sep 25 2017

Gradually strengthening offshore flow will bring a warming and
drying trend with mostly clear skies to the area through this week
and into the weekend. There will be some gusty north to northeast
winds at times over the region, especially below and through
passes and canyons. Temperatures will be a few degrees above
normal for many areas early this week, then increase to much
above normal for late this week and into the weekend.



Current gradients are between 2 and 3 mbs offshore. Skies are
clear. The clear skies and dry air are allowing wind free areas to
cool nicely. There are some NE winds developing but there is
little upper and zero thermal support so there will only be
isolated advisory gusts this morning. Most Santa Ana wind prone
areas will only see 15 to 25 mph winds this morning. Max temps
will rise 2 to 6 more degrees from ydys values and most areas will
be 4 to 6 degrees above normal and 8 to 12 degrees across some
coastal locations. The interior will also warm some from ydy but
not as much and will only be a couple degrees above normal.

Tonight the gradients will be a little more offshore and there
will be better upper support. This will be enough to generate wind
advisory level gusts 5 to 10 miles either side of the VTA/LA
county line. Aside from the slightly stronger winds Tuesday will
be very similar to today the only other change will be a few more
degrees of warming across the interior.

The offshore flow weakens Wednesday. There will not be enough push
to generate advisory level winds. Instead there will only be gusts
between 20 and 30 mph. There will be an earlier sea breeze and
coastal temps will cool a few degrees esp near the beaches but the
rest of the area will have temps similar to Tuesday.


Offshore flow weakens (but still remains offshore) on Thursday.
The upper support vanishes as well as the state will be under a
large cull area. Winds will not be a problem. There will be little
change in temperatures across interior areas but the coasts
will see a few degrees of cooling. The GFS and ECMWF now show
fairly flat 585 DM flow over the area on Fri and longer a
ridge. Offshore flow continues and Temps will really not change
to much. The ridge is now forecast to arrive on Sunday and if this
comes true there will be a few degrees of warming.




At 0915Z, there was no marine layer or marine inversion at KLAX.

Overall, high confidence in 12Z TAFs.

KLAX...high confidence in 12Z TAF. There is a 10% chance of east
winds to 8 knots 12Z-16Z.

KBUR...high confidence in 12Z TAF.



25/200 AM

For the Outer Waters, high confidence in current forecast. Winds
and seas are expected to remain below Small Craft Advisory (SCA)
levels through Thursday. On Friday, winds are expected to increase
to low-end SCA levels.

For the Inner Waters, high confidence in current forecast. Winds
and seas are expected to remain below SCA levels through Friday.
There will be some light north to northeast winds each night and
morning through Thursday across the nearshore waters from Ventura
south to Santa Monica.




A prolonged period of elevated fire danger is expected Wednesday
through Sunday due to the combination of gusty offshore winds,
very warm temperatures, low humidities, and very dry fuels. Brief
critical fire weather conditions will be possible at times on
Wednesday and again next weekend. There will be potential heat
impacts next weekend as triple digit temperatures are possible
for warmest valley locations.



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