Weather

367 
fxus66 klox 061601 
afdlox 


Southwest California area forecast discussion 
National Weather Service Los Angeles/Oxnard California 
900 am PDT Monday Oct 6 2008 


..significant warming trend expected through Wednesday... 


Short term...(today-wednesday) 
forecast looks in good shape. Grads have turned offshore this 
morning...with lax-dag near -2 mb and smx-bfl down to near -3. This 
has allowed some northeast flow to form in the mountains and favored 
valleys...with the strongest gusts near 25 miles per hour. This 
offshore...coupled with a building 592 dm ridge to our our 
southwest...and temperatures are on the rise. Morning soundings confirm 
this with an impressive 5c warming trend up through 700mb. The 
central coast will be the trickiest as some east wind has 
surfaced...but warming in store nonetheless. Stratus looks to remain 
at Bay once again today. 


..from previous discussion... 


Offshore trends will continue through Wednesday while the ridge of high 
pressure continues to strengthen over the area as well. Expect even 
warmer temperatures across the region both Tuesday and Wednesday as inland temperatures will 
reach the lower to middle 90s in most areas...with a few locations 
reaching near 100 degrees both days...while the coastal areas will 
vary between the lower 80s to lower 90s. Downtown Los Angeles should 
reach the lower 90s both Tuesday and Wednesday. Not expecting much in the way 
of low clouds across the area as offshore trends should keep 
forecast area clear. 


As far as the offshore winds...only expecting generally light to 
locally moderate northeast winds through the favored NE-SW passes 
and canyons of the la/vtu County mountains overnight and early morning 
hours as upper level support is weak and virtually no cold air 
advection to funnel into the Antelope Valley as a 1025 mb surface high 
builds in across the intermountain west. 


Long term...(thu-sun) 
a cooling trend will begin Thursday and Friday as an upper trough moves into 
the Pacific northwest helping to lower 500 mb and thickness levels a bit. By 
Friday...the GFS and European model (ecmwf) begin to have some differences. The ec 
advertises a cold upper level cut-off low (541 mb) dropping into southern 
Nevada by Friday night...while the GFS keeps an open trough over eastern Utah 
at the same time. Too early to figure out which will do the better 
job...but both models show a much stronger surface high will build into 
the intermountain west by this weekend. This should bring a chance 
of some decent offshore winds across our region by the weekend. If 
models are on track with cold air advection...a decent Santa Ana 
event could take place this weekend. Temperatures will be much cooler 
across the Antelope Valley compared to the valleys and coastal areas 
which should warm up into the 80s and possibly the 90s in the 
warmest locations. Marine layer should not be an issue through the 
period due to offshore trends. 




&& 


Aviation... 


06/1015z 


Marine clouds have not developed and should not redevelop for at 
least a few days. Weak offshore flow will create light-MDT turbulence and 
uddfs in and near to the mountains 


Klax...high confidence in ceiling and visibility unlimited taf. A 20 percent chance of 5sm haze 
from 13z to 17z. 


Kbur...high confidence in ceiling and visibility unlimited taf. 


&& 


Lox watches/warnings/advisories... 
none. 


&& 


$$ 


Public...kittell/Kaplan 
aviation...rorke 


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