SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
AFDLOX 200 PM PDT THU SEP 16 1999
CLOUDS MORE STUBBORN TO BURN OFF TODAY THANKS MAINLY TO A STRONGER
ONSHORE FLOW. ACARS AND BASIN PROFILERS CONTINUE TO INDICATE MARINE LYR
DEPTH IS VIRTUALLY UNCHANGED SINCE YESTERDAY. HOWEVER...WITH STRONGER
ONSHORE GRADIENTS...CLOUDS ARE HANGING IN A LITTLE STRONGER AND SHOULD
BE MOVING INLAND EARLIER TONIGHT THAN LAST NIGHT. SOME CONVECTION HAS
DEVELOPED OVER THE ERN MTNS BUT SO FAR PRECIP SEEMS TO BE CONFINED TO
THE 29 PALMS AREA. THUS WILL KEEP FORECAST DRY FOR OUR MTNS AND DSRTS.
VERY LITTLE CHANGE IN THE PATTERN THRU THE WEEKEND. PERSISTENT W CST
TROF WILL WEAKEN SLIGHTLY TONIGHT AS A VERY WEAK TRANSITORY RIDGE MOVES
THRU. HOWEVER THIS WILL QUICKLY BE REPLACED BY ANOTHER TROF WHICH WILL
MAINTAIN BELOW NORMAL TEMPS AND A STUBBORN MARINE LYR. THO THERE WILL
BE MINOR DAY TO DAY FLUCUTATIONS IN THE TEMPS DUE TO MARINE LYR DEPTH
AND MINOR GRADIENT CHANGES...JUST INDICATED NO CHANGE IN TEMPS NEXT TWO
DAYS.
BELOW NORMAL TEMPS WILL LIKELY CONTINUE AT LEAST THROUGH THE MIDDLE
PART OF NEXT WEEK. BEYOND THAT IT'S DIFFICULT TO SAY SINCE THE RUN TO
RUN CONSISTENCY OF THE MRF HAS BEEN VERY POOR LATELY. PREVIOUS RUN
INDICATED A DEEP H5 LOW OVER SO CAL FOR NEXT WEEKEND. LATEST RUN
INDICATES A STRONG RIDGE OVER SO CAL WITH A MODERATE OFFSHORE FLOW. IT
WILL BE INTERESTING TO SEE WHAT TONIGHT'S SOLUTION SHOWS.
LAX 0000. WOFFORD
.LAX...NONE.
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
AFDLOX 910 AM PDT THU SEP 16 1999
UPR LOW CENTERED OVER ERN NV INITIALIZED PRETTY WELL BY THE ETA THIS
MORNING. THE TAIL END OF THE TROF ASSOCD WITH THE LOW PASSED THROUGH SO
CAL AROUND 15Z THIS MORNING AND RESULTED IN SOME DRIZZLE/LIGHT RAIN
OVER THE COASTAL AREAS. CLOSER TO THE LOW CENTER ITSELF NEAR THE
AZ/NV/CA BORDER...AN AREA OF THUNDERSTORMS DEVELOPED AS THE TROF
INTERACTED WITH SOME MID LVL MSTR. DO NOT EXPECT ANY OF THESE
THUNDERSTORMS TO DEVELOP IN OUR AREA AS LOW WILL CONTINUE TO MOVE EAST
TODAY TAKING WITH IT ANY MECHANISM FOR SIGNIFICANT CONVECTION. THE
MODELS DO MAINTAIN A CYCLONIC CIRCULATION AT 850 AND 700 MB JUST
OFFSHORE...WHICH WILL MAINTAIN A SOUTHERLY FLOW OF AIR OVER THE INLAND
AREAS. HOWEVER...THIS SHOULD DO NOTHING MORE THAN ALLOW SOME AFTERNOON
CLOUDS TO DEVELOP OVER THE MTNS AND DSRTS.
OTHERWISE...PROFILERS AND ACARS DATA ACTUALLY INDICATE VERY LITTLE
CHANGE IN THE DEPTH OF THE MARINE LYR...ROUGHLY 2500 FEET. PRESSURE
GRADIENTS ARE SLIGHTLY STRONGER ONSHORE TODAY SO IF ANYTHING...EXPECT
AN EVEN SLOWER CLEARING PATTERN THIS AFTERNOON. BEACH AREAS ALONG THE
VENTURA AND SBA COUNTY COAST WILL LIKELY SEE VERY LITTLE...IF ANY
SUN...WHILE LA COUNTY BEACHES SHOULD CLEAR OUT BY MID AFTERNOON. MARINE
LYR WAS SURPRISINGLY VERY LATE TO RETURN LAST NIGHT IN LA COUNTY...BUT
WITH GRADIENTS TRENDING ONSHORE...EXPECT CLOUDS TO COME IN EARLIER
TONIGHT.
VERY LITTLE CHANGE IN THE OVERALL PATTERN THRU SAT. WEAK CYCLONIC FLOW
ALOFT WILL CONTINUE AS THE TROF ALONG THE W CST REMAINS IN PLACE.
THUS...VERY BLAH WEATHER WILL CONTINUE ALONG MOST OF THE CST WITH WELL
BELOW NORMAL TEMPS JUST ABOUT EVERYWHERE S OF PT CONCEPTION. N OF THE
POINT...TEMPS WILL BE NEAR SEASONAL NORMS...BUT OVERALL WEATHER WILL BE
SIMILAR WITH MORNING CLOUDS CLEARING TO NEAR THE BEACHES BY AFTERNOON.
LAX 100. WOFFORD
.LAX...NONE.