AREA FORECAST DISCUSSION

 
 FXUS66 KLOX 121035
 AFDLOX
 
 SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
 NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
 330 AM PDT SUN OCT 12 2008
 
 .SHORT TERM...
 WINDS ARE THE CONCERN FOR THE NEXT THREE DAYS. BOTH THE DAG AND BFL 
 GRADIENTS ARE OFFSHORE AND ARE TRENDING OFFSHORE. THE L.A. MTNS 
 (INCLUDING THE SANTA MONICA RANGE) ARE BLOWING THROUGH THE PASSES 
 AND CANYONS WHERE ADVISORY LEVEL GUSTS WILL CONTINUE THROUGH THE 
 MORNING. ACROSS THE INTERIOR VLYS THERE WILL BE PLENTY OF FROST 
 WHERE EVEN NOW MOST TEMPS ARE IN THE 33 TO 34 DEGREE RANGE.
 
 OVERNIGHT OFFSHORE GRADS PEAK AT -6.8 TO DAG AND -3.7 TO BFL. THE 
 WRF FCSTS A WIND MAX OF 50 KT CENTERED OVER LAGUNA PEAK AT 950 MB 
 SHIFTING TO THE NORTHEAST WITH ANOTHER MAX OF 45 KT CENTERED OVER 
 SANTA CLARITA VLY. THKNS INCREASES FROM 554 TO 556 OVERNIGHT AND 
 THEN SURGES TO 564DM DURING THE DAY. THIS WARM AIR ADVECTION SHOULD 
 KEEP THE EVENT A STRONG ADVISORY RATHER THAN A WARNING. THERE SHOULD 
 STILL BE SOME PATCHY FROST IN THE INTERIOR OF SLO AND SBA COUNTIES 
 WHERE THE COOL AIR WILL REMAIN AND THERE WILL NOT BE ANY WINDS.
 
 MONDAYS TEMPS WILL WARM NICELY WITH THE ADIABATIC COMPRESSION DRIVEN 
 BY THE NE WINDS. THE COASTS AND THE VLYS WILL BE QUITE WARM BUT 
 WITHOUT THE COMPRESSIONAL HEATING THE MTNS AND DESERTS WILL STILL BE 
 ON THE COOL SIDE. THE WINDS WILL DROP SOMEWHAT IN THE AFTERNOON WITH 
 THE DIURNAL CYCLE BUT WILL INCREASE STEADILY THROUGH THE NIGHT.
 
 MONDAY NIGHT WILL BE WARMER THAN TONIGHT AND THERE WILL BE NO FROST. 
 SOME LOW TEMPS IN THE WINDIER AREAS WILL BE IN THE UPPER 60S OR EVEN 
 LOWER 70S. WINDS WILL BE SIMILAR TO TONIGHT WITH ANOTHER 6DM OF 
 THKNS INCREASE FORECAST FROM 00Z TO 12Z. UPPER LEVEL SUPPORT AND SFC 
 GRADIENT SUPPORT WILL MIRROR TONIGHT.
 
 TUESDAY NIGHT AND WEDNESDAY THE HIGH MOVES TO THE EAST. THERE WILL 
 STILL BE OFFSHORE FLOW BUT IT WILL BE MUCH WEAKER...MORE IN THE 15 
 TO 25 MPH RANGE. THE WEAKER SFC GRADS WILL ALLOW FOR A BETTER SEA 
 BREEZE AND CREATE LESS COMPRESSIONAL WARMING AS WELL BOTH OF WHICH 
 WILL LEAD TO COOL TEMPS ALONG THE COAST AND VLYS TEMPS INLAND TEMPS 
 WILL REMAIN ABOUT THE SAME.
 
 .LONG TERM...
 BOTH EC AND GFS AGREE THAT THURSDAY AND FRIDAY WILL BE COOLING DAYS. 
 LOWER HGTS AND WEAK OFFSHORE FLOW WILL KEEP THE COOLING TREND GOING 
 BUT WILL INHIBIT ANY MARINE LAYER.
 
 A TROF BEGINS TO APPROACH THE COAST SATURDAY AND IT IS POSSIBLE THAT 
 A MARINE LAYER WILL FORM BUT RIGHT NOW IT LOOKS LIKE THE BEST CHANCE 
 FOR THAT IS NEXT SUNDAY WHEN THE TROF IS FCST TO BE ATOP OF 
 CALIFORNIA. SATURDAY LOOKS LIKE IT WILL JUST BE COOLER WITH THE 
 LOWERING OF THE HGTS.
 
 &&
 
 .AVIATION...
 
 12/1100Z
 
 HIGH CONFIDENCE IN VFR CONDITIONS EVERYWHERE. LLWS WILL BE A 
 CONCERN IN AND AROUND THE MOUNTAINS.
 
 KLAX...HIGH CONFIDENCE IN CAVU TAF.
 
 KBUR...HIGH CONFIDENCE CAVU TAF. LGT-MDT TURBULENCE FROM SFC TO 050 
 LIKELY TODAY AND TONIGHT.
 
 &&
 
 .LOX WATCHES/WARNINGS/ADVISORIES...
 RED FLAG WARNING (SEE LAXRFWLOX).
 FIRE WEATHER WATCH (SEE LAXRFWLOX).
 WIND ADVISORY (SEE LAXNPWLOX).
 FROST ADVISORY (SEE LAXNPWLOX).
 SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX).
 
 &&
 
 

 
 PUBLIC...RORKE
 AVIATION...KAPLAN
 
 WWW.WEATHER.GOV/LOSANGELES
 
 
 

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