FXUS64 KLCH 251806
AFDLCH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
1206 PM CST WED NOV 25 2009
.AVIATION...WEAK SURFACE HIGH OVER TEXAS WILL CONTINUE TO FEED A
DRY NORTHERLY FLOW THROUGH THE AREA. A STATIONARY FRONT OUT OVER
THE GULF AND COLD ADVECTION SETTING UP A TIGHTER GRADIENT OVER THE
NORTHERN GULF. THE RESULT IS GUSTY NORTHERLY WINDS AT THE
TERMINALS CLOSER TO THE COAST. WINDS WILL DIMINISH AS THE SUN SETS
DUE TO LOSS OF SOLAR MIXING. SHOULD SEE A REPEAT ON TURKEY DAY.
SWEENEY
&&
.PREV DISCUSSION... /ISSUED 929 AM CST WED NOV 25 2009/
UPDATE...
ONLY CHANGE DURING THE MORNING UPDATE PERIOD WAS TO EXTEND THE
SMALL CRAFT ADVISORY THROUGH THE REMAINDER OF THE MORNING OVER THE
OUTER COASTAL WATERS AS MSAS ANALYSIS AND INTERPOLATION FROM RIG
REPORTS STILL SHOW SCA CONDITIONS BEYOND 20 NM. GUIDANCE PRETTY
CONSISTENT WITH WINDS OVER COASTAL WATERS FALLING BELOW SCA
CRITERIA BY AFTERNOON. OTHERWISE...FORECAST SEEMS TO BE ON TRACK.
RUA
PREV DISCUSSION... /ISSUED 349 AM CST WED NOV 25 2009/
DISCUSSION...
LATEST SFC ANALYSIS SHOWS THE COLD FRONT WHICH CROSSED ON TUESDAY
IS NOW JUST EAST OF THE FORECAST AREA AND EXTENDING OVER THE FAR
OFFSHORE WATERS. WATER VAPOR IMAGERY SHOWS DRY AIR ON THE BACKSIDE
OF THE MID-LEVEL SHORTWAVE TROF NOW ENTERING THE FORECAST AREA...
WHICH IS CORROBORATED IN IR PIX AND SFC OBS AS MID/HIGH CLOUDS ARE
STEADILY DEPARTING THE REGION. MEANWHILE DEWPOINTS HAVE FALLEN AS
FAR SOUTH AS THE UPPER 30S OVER PORTIONS OF THE FORECAST AREA
THOUGH MOST OF THE AREA STILL REPORTING READINGS IN THE LOWER/MID
40S. REGIONAL 88DS INDICATE THAT ALL OF THE PRECIP HAS NOW MOVED
EAST OF THE AREA.
NOT MANY CHANGES TO INHERITED GRIDS/FORECASTS AS PREVIOUS THINKING
STILL RINGS TRUE THIS MORNING. DRIER CONDITIONS ON NRLY FLOW
THROUGH THE COLUMN WILL USHER IN MAINLY CLEAR SKIES FOR THE NEXT
COUPLE OF DAYS. MEANWHILE GOOD CAA BEHIND THE FRONT WILL ALLOW FOR
COOLER TEMPS...ESPECIALLY THE NEXT COUPLE OF NIGHTS AS GOOD
RADIATIONAL CONDITIONS WILL PRODUCE MINS IN THE 30S OVER MUCH OF
THE AREA.
CHANGES COMMENCE BY FRIDAY AS SFC HIGH PRESSURE SLIDES EAST OF THE
FORECAST AREA ALLOWING RETURN FLOW TO DEVELOP. MEANWHILE WEAK
IMPULSES ALOFT BEGIN TO TRAVERSE THE AREA IN DEVELOPING SWRLY
MID/UPPER-LEVEL FLOW. RAIN CHANCES RETURN TO THE FORECAST SATURDAY
NIGHT AS THE FIRST OF THESE IMPULSES APPROACHES. BEST RAIN CHANCES
COME SUNDAY NIGHT AND MONDAY AS MID-LEVEL STORM SYSTEM INDUCES
CYCLOGENESIS OVER NRN TX AND THEN PULLS ASSOCIATED FRONTAL
BOUNDARY ACROSS THE REGION. TRICKY PART OF THE FORECAST COMES IN
WAKE OF THIS SYSTEM AS LONGER-RANGE MODELS DIFFER IN THE DETAILS
ABOUT POTENTIAL OF WRAP-AROUND PRECIPITATION...FOR NOW HAVE JUST
KEPT SLIGHT CHANCE POPS INTO TUESDAY AND WILL LET FORECASTS DOWN
THE ROAD BETTER DEFINE THESE RAIN CHANCES.
MARINE...SCA TO CONTINUE THROUGH 15Z THIS MORNING AS STRONG NRLY
FLOW PERSISTS OVER THE COASTAL WATERS. CAA OVER THE WATERS WILL
GRADUALLY WEAKEN ALTHOUGH PRESSURE GRADIENT WILL MAINTAIN AT LEAST
A MODERATE OFFSHORE FLOW THROUGH THURSDAY. LIGHT WINDS ANTICIPATED
FOR FRIDAY/SATURDAY AS HIGH PRESSURE MOVES PAST THE REGION...THEN
SRLY WINDS PICK UP FOR SUNDAY AS THE PREVIOUSLY MENTIONED LOW
DEVELOPS TO OUR WEST.
25
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 67 40 65 40 63 / 0 0 0 0 0
KBPT 67 40 65 41 65 / 0 0 0 0 0
KAEX 65 37 64 36 63 / 0 0 0 0 0
KLFT 66 42 65 39 62 / 0 0 0 0 0
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
ZONES: WATERS FROM CAMERON, LA TO HIGH ISLAND, TX EXTENDING
FROM 20 NM TO 60 NM...WATERS FROM INTRACOASTAL CITY, LA TO
CAMERON, LA EXTENDING FROM 20 NM TO 60 NM...WATERS FROM
LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY, LA EXTENDING
FROM 20 NM TO 60 NM.
&&
$$
