092 
fxus66 klox 231144 
afdlox 


Southwest California area forecast discussion 
National Weather Service Los Angeles/Oxnard California 
345 am PST Monday Nov 23 2009 


Synopsis... 


A weak Santa Ana will keep the skies clear and generate local canyon 
winds today through Wednesday. Thanksgiving will be very pleasant 
with clear skies and slightly warmer than normal maximum 
temperatures. The marine layer will make a brief appearance along 
the coast Friday and Saturday but offshore flow and warmer temperatures 
will reestablish by Sunday. 


&& 


Short term (today-thu)... 
moderate wind event in progress with advisory level winds blowing 
through the I-5 corridor and the Santa Ynez range. Whittaker peak is 
howling at near 70 miles per hour but the winds are in perfect alignment to 
cause that very isolated wind maximum. Local north winds are also 
surfacing across the central coast. Still some cold air spilling 
into the area so despite the offshore flow maximum temperatures will not warm 
as much as possible along the coast and will cool over the mountains and 
deserts. 


Winds turn northeast tonight and stay that way through Wednesday. 
This will cut off the Santa Barbara South Coast but will light up 
the Ventura valleys and coasts. Wind advisories may be needed tonight 
for the mountains and Ventura valleys and possible the far western portion 
of the San Fernando Valley. Low temperatures each night will be very 
variable with wind sheltered locations as much as 20 degrees cooler 
than neighboring windy areas. Maximum temperatures each day Tuesday and Wednesday will be 
several degrees above normal along the coasts and valley. Wednesday may be a 
degree warmer than Tuesday but for all intents and purposes temperatures will 
be the same. Mountains and deserts will warm some each day but with no 
help from downsloping the warming will not be as significant as the 
coasts and valleys. 


The offshore flow weakens considerable for Thanksgiving. But it 
will be enough to keep the skies clear and temperatures though cooler than 
Wednesday will still be above normal. Looks like a chamber of 
Commerce Holiday for the Southland. 


Long term (fri-sun)... 
both the GFS and the ec push a trough and a dry cold front through the 
area Friday. The GFS solution is a little stronger than the flatter ec 
solution. For those of you keeping score this is the exact opposite of 
last nights solution when the ec was more aggressive. The model 
differences are not that problematic however as both lower heights and 
rapidly switch the low level flow from offshore to onshore. This 
should be enough to bring low clouds back to the coastal sections. 
Maximum temperatures will plummet everywhere with 5 to 10 degrees of cooling 
likely form thursdays numbers. 


A ridge begins to build back in Saturday and the flow begins to 
transition to a more northerly direction. This should scour out the 
marine layer everywhere except the l.A. Coast which is well 
sheltered from a north push. Temperatures will bounce back a little with 
rising heights. 


Northeast flow sets up Sunday and skies should be clear and maximum 
temperatures should rise. 


&& 


Aviation... 


23/1140z. 


S of Point Conception...high confidence for VFR conds with light to 
moderate offshore flow. Some low level wind shear likely for kbur later this morning 
as well as kcma. Expect some uddf across the la/vtu County mountains as 
well as winds shift to NE by 17z. 


North of Point Conception...generally VFR conds across central coast. 
Some lingering LIFR conds near kprb and IFR ceilings across slow/sba 
inland valleys through 18z...then clearing this afternoon. 


Klax...good confidence in taf. A 20 percent chance of MVFR visible 
12z-17z. 


Kbur...very good confidence in ceiling/visible forecast. Winds will be 
erratic overnight and during the morning with calm...east 4-8kt and 
north winds 8 to 12 knots all equally possible. A 20 percent chance of 
north winds 15 to 20 knots. Light turbulence surface-070 Monday morning and 
afternoon. 
&& 


Lox watches/warnings/advisories... 
Wind Advisory (see laxnpwlox). 
Small Craft Advisory (see laxmwwlox). 


&& 


$$ 


Public...rorke 
aviation...Kaplan 
synopsis...asr 


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