Re: WET PATTERN EXPECTED THURSDAY THROUGH SUNDAY

AREA FORECAST DISCUSSION


FXUS66 KLOX 082142
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
145 PM PST THU FEB 8 2007

.SHORT TERM (TONIGHT THROUGH SUNDAY)...
LATEST SATELLITE SHOWS A LARGE UPPER LOW OVER THE NORTHEAST PACIFIC
WITH SEVERAL VORT MAXES SWIRLING AROUND THE UPPER LOW. ALSO...LATEST
SATELLITE IMAGERY SHOWS LONG PLUME OF MOISTURE WRAPPING AROUND THE
UPPER LOW. SO...THIS FEATURE WILL BE THE MAIN WEATHER PLAYER FOR US
IN THE SHORT TERM.

12Z GFS/WRF ARE IN RELATIVELY GOOD AGREEMENT THROUGH SATURDAY EVENING
WITH REGARD TO OVERALL SYNOPTIC PATTERN AND MOISTURE...ALTHOUGH GFS
IS MORE BULLISH WITH PRECIP CHANCES ON FRIDAY AFTERNOON...BUT THE
WRF SHOWS PLENTY OF MOISTURE WHICH WARRANTS SOME CHANCE OF POPS. SO
HAVE LEANED TOWARDS THE GFS FOR PRECIP TIMING...EXPECTING A CHANCE
OR SLIGHT CHANCE OF SHOWERS NORTH OF PT CONCEPTION TONIGHT. ON FRIDAY
RAIN WILL BECOME LIKELY NORTH OF PT CONCEPTION WITH A SLIGHT CHANCE
FRIDAY AFTERNOON DOWN TO LAX COUNTY. FRIDAY NIGHT SHOULD SEE LIKELY
TO CHANCE POPS FOR ALL AREAS. ON SATURDAY...BOTH GFS/WRF INDICATE
MOST SIGNIFICANT PRECIP CHANCES...WITH RAIN BECOMING LIKELY IN THE
MORNING AND CONTINUING THROUGH THE DAY...WITH MODERATE TO LOCALLY
HEAVY RAINFALL POSSIBLE ACROSS THE ENTIRE AREA. FOR SATURDAY NIGHT
AND SUNDAY...MOIST WESTERLY FLOW WILL KEEP A CHANCE OF SHOWERS
ACROSS THE ENTIRE AREA...ALTHOUGH THE WRF WOULD INDICATE A HIGHER
CHANCE OF PRECIP ACROSS THE AREA.

AS FOR ACTUAL QPF AMOUNTS...AT THIS TIME...BELIEVE 1-2 INCHES IN THE
FOOTHILLS AND MOUNTAINS IS VERY REASONABLE WITH EVEN LOCALLY HIGHER
AMOUNTS VERY LIKELY. SO...BURN AREAS COULD HAVE SOME FLOOD/DEBRIS
FLOW ISSUES. SO...IF THE NEXT COUPLE OF MODEL RUNS MAINTAIN THIS
CURRENT THINKING...EITHER THE MIDNIGHT SHIFT TONIGHT OR YOURS TRULY
ON THE FRIDAY DAY SHIFT WILL LIKELY ISSUE FLASH FLOOD WATCHES FOR
THE BURN AREAS.

WITH THIS RAIN EVENT...SNOW LEVELS ARE NOT EXPECTED TO DROP
SIGNIFICANTLY AS SYSTEM IS RATHER WARM. SO...BY SATURDAY NIGHT
AND SUNDAY...WILL EXPECT SNOW LEVELS TO DROP TO AROUND 7000 FEET
AT THE WORST. SO...WILL NOT EXPECT MUCH IN THE WAY OF WINTER
WEATHER PROBLEMS FOR THE MOUNTAINS.

.LONG TERM (SUNDAY NIGHT THROUGH THURSDAY)...
COMBINATION OF ABUNDANT LOW LEVEL MOISTURE AND CYCLONIC FLOW SHOULD
KEEP SKIES MOSTLY CLOUDY AND MAINTAIN A CHANCE OF SHOWERS ACROSS
THE ENTIRE AREA THROUGH TUESDAY/TUESDAY NIGHT. ON WEDNESDAY AND
THURSDAY...EXPECT RIDGE TO DEVELOP OVER THE AREA. SO...THINGS
SHOULD DRY OUT AND TEMPERATURES SHOULD REBOUND SLIGHTLY.

&&

.AVIATION...
NORTH OF POINT CONCEPTION...MOIST SOUTHWEST FLOW ALOFT WILL BRING
OPPORTUNITIES FOR LIGHT TO MODERATE RAINFALL MAINLY TO THE EXTREME
NORTHERN PORTIONS OF THE FORECAST AREA LATE TONIGHT AND EARLY
FRIDAY. WITH AMPLE MOISTURE ACROSS THE CENTRAL COAST...NIGHT AND
MORNING FOG IS QUITE LIKELY IN PORTIONS OF THE REGION. LOCAL IFR
CONDITIONS ARE POSSIBLE.

SOUTH OF POINT CONCEPTION...WEAK ONSHORE FLOW WILL PROVIDE ENOUGH
MOISTURE FOR LOCAL NIGHT AND MORNING LOW CLOUDS AND FOG WITH LOCALLY
DENSE CONDITIONS.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
NONE

&&





PUBLIC...THOMPSON
AVIATION...SWEET