Area Forecast Discussion
Issued by NWS Los Angeles, CA

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FXUS66 KLOX 240954

254 AM PDT Sun Sep 24 2017

Gradually strengthening offshore flow will bring a warming and
drying trend with mostly clear skies to the area through next
week. 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 by
early next week, then increase to much above normal by late in
the week.



Skies are clear and there is no marine layer nor much of an
inversion. Gradients are offshore both from the north and the east
and are more offshore than they were at this time ydy (esp from
the east) The coasts and vlys will see a good jump up in temps
today due to the sunny skies and offshore flow and all cst/vly
sites will jump up to near normal max temps today (most areas have
had below normal temps now for the last 11 days) Cool air moving
in from the great basin will keep the temps across the interior on
the cool side. There will be some morning north to north east
canyon winds 15 to 25 mph and perhaps a few gusts to 35 mph but
northing widespread enough to warrant an advisory.

On Monday offshore gradients will be about 1 MB strong in each
direction. This will lead to a little strong canyon winds in the
morning and there may be a need for some low end advisories along
the LA/VTA county line in the morning. Max temps will rise another
3 to 5 degrees. The cst/vly areas will all be 2 to 4 degrees above
normal except the central coast with the max temps will be 8 to 10
degrees warmer than normal. Despite the warming the interior will
remain blo normal.

Gradients actually relax a little on Tuesday...but there is a
little better upper air support and Tuesday might be the best day
for wind advisories. Again the best area for the winds will be 10
miles either side of the LA/VTA county line. Look for another 2 to
4 degrees of warming across the area and the interior will finally
reach normal max temps. Max temps across the vlys will all be in
the 90s and the coasts will be mostly in the 80s with a smattering
of readings in the lower 90s.


An upper low near Yuma will bend the upper level flow pattern into
a NNE direction on Wednesday. Earlier mdl runs had the low a
little further to the west which would have added a little more
oomph to the offshore winds. The current solution would support
low end advisory winds in the usual places. Max temps will be very
similar to Tuesdays much above normal values.

Offshore flow weakens (but still remains offshore) on Thu. 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 across the interior but the coasts and vlys will cool some
exp the coast.

On Friday the GFS is a little more aggressive with a pop up ridge
and a warming trend than the EC. This looks like a warm pattern
and will favor the warmer GFS.

Although the GFS indicates a weak trof over the state on Saturday
while the EC forecasts a weak ridge the 500 mb hgts only differ by
1 DM. Offshore flow is forecast to increase and max temps should
head up again to warmer readings.




At 0900Z, there was a weak marine inversion at KLAX, based at 1000
feet. The top of the inversion was 2100 feet with a temperature of
18 degrees Celsius.

Overall, high confidence in 12Z TAFs. There is a 20% chance of
IFR/LIFR conditions at KSMX 12Z-15Z.

KLAX...high confidence in current forecast. East to southeast
winds will remain below 8 knots this morning.

KBUR...high confidence in current TAF.



24/130 AM

For the Outer Waters, good confidence in current forecast. Winds
and seas are expected to remain below Small Craft Advisory (SCA)
levels through Thursday although there is a 30% chance of SCA
level gusts across western sections of PZZ670/673 Monday afternoon
and evening.

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


PZ...Small Craft Advisory in effect until 3 AM PDT early this
      morning for zones 670-673-676. (See LAXMWWLOX).


A prolonged period of elevated fire danger is expected Tuesday
through Saturday 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 especially
in the mountains. There will be potential heat impacts by Friday
and Saturday as triple digit temperatures are possible for warmest
valley locations.



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