000
FXUS64 KLCH 210417
AFDLCH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
1117 PM CDT MON MAY 20 2013

.AVIATION UPDATE...REGARDING 06Z TAF ISSUANCE. NO MAJOR CHANGES TO
TAFS. ANTICIPATING ALL TERMINALS TO FALL WITHIN MVFR OVERNIGHT AS
SOUTHERLIES MAINTAIN A STEADY STREAM OF MOISTURE INLAND.

&&

MARCOTTE


&&

.PREV DISCUSSION... /ISSUED 1017 PM CDT MON MAY 20 2013/

DISCUSSION...
CURRENT FORECAST GENERALLY ON TARGET THIS EVENING. BIGGEST CHANGE
WAS TO INCREASE FORECAST LOW TEMPERATURES A BIT WITH ANOTHER
CLOUDY...HUMID...AND SOMEWHAT BREEZY NIGHT ON TAP.

13

PREV DISCUSSION... /ISSUED 645 PM CDT MON MAY 20 2013/

AVIATION UPDATE...REGARDING 00Z TAF ISSUANCE. MVFR CLOUDINESS
CURRENTLY OVER LCH AND BPT WILL OVERSPREAD THE TERMINALS OF LFT/ARA
AND AEX AS THE NIGHT PROGRESSES. OTHERWISE...MODERATE AND GUSTY
SOUTHERLIES WILL GRADUALLY LAY DOWN DURING THE EARLY EVENING.

MARCOTTE

PREV DISCUSSION... /ISSUED 228 PM CDT MON MAY 20 2013/

DISCUSSION...THE REGION REMAINS BETWEEN HIGH PRESSURE OVER THE
ATLANTIC AND A SURFACE LOW AND ASSOCIATED COLD FRONT OVER THE
PLAINS. THIS CONTINUES TO DRAG IN A WARM AND MOIST AIRMASS FROM
THE GULF AND CARIBBEAN AND WITH THE PRESSURE GRADIENT FAIRLY TIGHT
BETWEEN THE TWO AFOREMENTIONED SYSTEMS, WINDS REMAIN BREEZY. THESE
CONDITIONS WILL CONTINUE THROUGH WEDNESDAY WITH TEMPS RUNNING
ABOVE NORMAL... MOST NOTABLY ON THE LOWS.

THE UPPER TROUGH OVER THE CENTRAL SECTIONS OF THE COUNTRY WILL
SLOWLY MOVE EAST THROUGH THE NEXT 24 HRS GRADUALLY ERODING THE
LOW TO MID LVL RIDGE CURRENTLY IN PLACE ACROSS THE AREA WHICH WILL
IN TURN ALLOW POPS TO INCREASE BY TUESDAY/TUE AFTERNOON. THE FLOW
ALOFT WILL BECOME DIVERGENT LATER TUE AND WED AND WITH AN ERODED
CAP, POTENTIAL FOCUS FROM A FEW OUTFLOW BOUNDARIES, AND A FAIR
AMOUNT OF INSTABILITY AN ISOLATED MARGINALLY SEVERE STORM MAY BE
POSSIBLE LATER TUE INTO WED. THE AREA OF CONCERN WILL GENERALLY
REMAIN FROM THE EAST TX LAKES THROUGH CENLA. ALSO DURING THE
MIDDLE OF THE WEEK, THE UPPER TROUGH WILL MOVE BY TO THE NORTH
ALLOWING A WEAK SURFACE BOUNDARY TO DRIFT SOUTHWARD. THE BOUNDARY
MAY HAVE A SHOT OF DRIFTING TO NEAR THE COAST, PER THE 12Z GFS,
WHICH WOULD ALLOW A SLIGHTLY DRIER AIRMASS TO MIX IN BEFORE THE
WEEKEND. THE ECMWF DELAYS THE "DRIER" AIRMASS UNTIL THE WEEKEND AS
A RIDGE WORKS ACROSS THE EAST HALF OF THE COUNTRY. WITH EITHER
SOLUTION THE AMOUNT OF DRIER AIR WOULD BE FAIRLY LOW, HOWEVER THIS
MAY ALLOW LOW TEMPERATURES TO FALL TO OR POSSIBLY SLIGHTLY BELOW
CLIMO WHILE HIGHS REMAIN NEAR NORMAL. SPLIT THE DIFFERENCE BETWEEN
THE MODELS AND COOLED LOWS A COUPLE OF DEGREES FROM THE PREVIOUS
FORECAST FOR THE COMING WEEKEND.

MARINE...A FAIRLY TIGHT PRESSURE GRADIENT WILL REMAIN OVER THE
COASTAL WATERS THROUGH TUE MORNING WITH WINDS AT OR SLIGHTLY ABOVE
15 KTS. A WEAK BOUNDARY WILL APPROACH THE COASTAL WATERS BY MID
WEEK WEAKENING THE GRADIENT.

&&

.PRELIMINARY POINT TEMPS/POPS...
KLCH  76  86  75  86  71 /  10  10  20  50  20
KBPT  76  86  75  86  71 /  10  10  20  30  20
KAEX  76  90  71  87  68 /  10  20  40  50  20
KLFT  77  88  74  87  71 /  10  10  20  40  20

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT EXERCISE CAUTION UNTIL 7 AM CDT TUESDAY FOR THE
     FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH
     ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY
     TO CAMERON LA OUT 20 NM...COASTAL WATERS FROM LOWER
     ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA OUT 20 NM...
     WATERS FROM INTRACOASTAL CITY TO CAMERON LA FROM 20 TO 60
     NM...WATERS FROM CAMERON LA TO HIGH ISLAND TX FROM 20 TO 60
     NM...WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL
     CITY LA FROM 20 TO 60 NM.

&&

$$