HAMweather.com Area Forecast Discussion for County Warning Area LOX

Thu, 16 Feb 2012 04:27:00 GMT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
830 PM PST WED FEB 15 2012

.SYNOPSIS...

HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT AND THURSDAY... 
PRODUCING ABOVE NORMAL AFTERNOON TEMPERATURES THROUGH FRIDAY ALONG 
WITH GUSTY NORTHEAST WINDS AT TIMES. IT WILL BE COOLER OVER THE 
WEEKEND AS THE HIGH PRESSURE WEAKENS AND A LOW PRESSURE AREA SKIRTS 
JUST EAST OF THE AREA. HIGH PRESSURE SHOULD MOVE BACK IN EARLY NEXT 
WEEK FOR WARMING TEMPERATURES THROUGH MID WEEK.

.SHORT TERM (TONIGHT-SAT)...COLD UPPER LEVEL LOW PRESSURE SYSTEM
MOVED THROUGH THE SOUTHLAND TODAY BRINGING SHOWERS TO THE REGION.
THE MOST WIDESPREAD COVERAGE OCCURRED ACROSS LOS ANGELES COUNTY...WITH
AMOUNTS RANGING BETWEEN .50 AND .75 INCHES ACROSS SOME FOOTHILL LOCATIONS
ADJACENT TO THE SAN GABRIELS. SNOW LEVELS FELL AS LOW AS 2500 FEET
TODAY...WITH ACCUMULATIONS OF 1 TO 3 INCHES ABOVE 3000 FEET. 

UPPER LOW HAS NOW SHIFTED EAST OF THE FORECAST AREA AND WILL CONTINUE
TO TRACK SOUTHEASTWARD OVERNIGHT. MOST OF THE PRECIPITATION HAS ENDED
ACROSS THE FORECAST AREA...HOWEVER THERE COULD STILL BE SOME WRAP AROUND
SHOWERS THAT MOVE INTO THE ANTELOPE VALLEY AND MOUNTAINS TONIGHT. 
COLD AIR CONTINUES TO FILTER INTO THE SOUTHLAND...WITH SNOW LEVELS
RANGING BETWEEN 2500 AND 3000 FEET. ANY ADDITIONAL SNOW ACCUMULATIONS
ARE EXPECTED TO BE LIGHT. 

THE MAIN FOCUS WILL NOW SHIFT TO INCREASING OFFSHORE WINDS ACROSS SOUTHERN
CALIFORNIA TONIGHT INTO THURSDAY. ALREADY SEEING SOME NORTHERLY WINDS
GUSTING BETWEEN 30 AND 50 MPH ACROSS PORTIONS OF THE SOUTHLAND. LATER
THIS EVENING AND DURING THE OVERNIGHT HOURS...THERE WILL BE INCREASING
UPPER LEVEL WIND SUPPORT AND SUBSIDENCE. IN FACT...LATEST 00Z NAM MODEL
SHOWS A MARKED INCREASE IN UPPER LEVEL WINDS BETWEEN 06Z AND 09Z. AS A 
RESULT...HAVE BUMPED UP TIMING FOR WIND ADVISORIES AND HIGH WIND WARNINGS.
THE STRONGEST WINDS ARE EXPECTED TO OCCUR LATER THIS EVENING INTO THURSDAY
MORNING...WITH THE FOCUS OF BEST UPPER LEVEL WIND SUPPORT ACROSS LOS ANGELES
COUNTY. DAMAGING WIND GUSTS TO 65 MPH CAN BE EXPECTED IN THE
MOUNTAINS...INCLUDING THE SANTA MONICAS. WITH AMPLE COLD AIR AND STRONG
UPPER LEVEL WINDS...THIS APPEARS TO BE AN EVENT THAT WILL BRING GUSTY WINDS TO
PORTIONS OF THE SAN GABRIEL VALLEY...ESPECIALLY FOOTHILL COMMUNITIES. AS A
RESULT...THE SAN GABRIEL VALLEY WAS INCLUDED IN THE WIND ADVISORY...WITH
GUSTS TO 50 MPH LIKELY IN FAVORED LOCATIONS. 

*** FROM PREVIOUS DISCUSSION ***
WINDS WILL DIMINISH BELOW WARNING THRESHOLDS THURSDAY AFTERNOON THOUGH AREAS
OF GUSTY NORTHEAST WINDS MAY PERSIST THROUGH EARLY FRIDAY MORNING. THE 
REMNANTS OF THE SYSTEM OVER THE CENTRAL PACIFIC THIS AFTERNOON IS 
EXPECTED TO MOVE OVER THE AREA SATURDAY AND WHILE TEMPERATURES WARM 
THROUGH FRIDAY A COOLING TREND IS LIKELY SATURDAY AND RANGE FROM 2 
TO 5 DEGREES BELOW NORMAL.

.LONG TERM (SUN-WED)...A COOLING TREND IS LIKELY SUNDAY AS NORTH 
WINDS INCREASE AND REINFORCE THE COOLER AIR OVER THE AREA. NORTHWEST 
AND NORTH GALES ARE LIKELY NEAR SHORE AND WIND ADVISORIES WILL 
LIKELY BE POSTED OVER THE COASTAL AND DESERT AREAS. A BROAD AND 
STRONG RIDGE OF HIGH PRESSURE WILL BUILD OVER THE EASTERN PACIFIC 
MONDAY THROUGH WEDNESDAY. TEMPERATURES WILL MODERATE OVER THE AREA 
AND GRADUALLY WARM WITH NORMAL TEMPERATURES LIKELY BY TUESDAY.

.AVIATION...15/2350Z...HI CONFIDENCE OVERALL IN THE CURRENT TAF 
PACKAGE WITH VFR CONDITIONS EXPECTED THRU THU...EXCEPT FOR A 50 
PERCENT CHANCE OF LIFR CONDITIONS DUE TO DENSE FOG AT KPRB LATE 
TONIGHT INTO THU MORNING. GUSTY NW TO N WINDS WILL AFFECT MANY OF 
THE AIRFIELDS THRU THIS EVENING...WITH LOW LEVEL WIND SHEAR POSSIBLE 
AT TIMES AT KSBA...ALTHO IT CANNOT BE RULED OUT AT KBUR AS WELL. 
GUSTY N WINDS ARE EXPECTED AT KBUR AND KVNY THU MORNING THRU THE 
AFTERNOON...WITH LOW LEVEL WIND SHEAR EXPECTED AT KBUR.

KLAX...GENERALLY HI CONFIDENCE IN THE CURRENT TAF WITH VFR 
CONDITIONS EXPECTED THRU THU EVENING. THERE WILL BE GUSTY W TO NW 
WINDS AT TIMES THRU THU.

KBUR...GENERALLY HI CONFIDENCE IN THE CURRENT TAF WITH VFR 
CONDITIONS EXPECTED THRU THU. THERE WILL BE GUSTY NW WINDS THRU THIS 
EVENING AND GUSTY N WINDS FROM THU MORNING THRU THE AFTERNOON. LOW 
LEVEL WIND SHEAR IS ALSO EXPECTED ON THU...BUT THERE IS A 10-20 
PERCENT CHANCE OF THIS OCCURRING THIS EVENING AS WELL.

.LOX WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING (SEE LAXNPWLOX).
WIND ADVISORY (SEE LAXNPWLOX).
WINTER WEATHER ADVISORY (SEE LAXWSWLOX).
GALE WARNING (SEE LAXMWWLOX).
HIGH RIP CURRENT RISK (SEE LAXSRFLOX).