000
FXUS64 KLCH 181642
AFDLCH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
1142 AM CDT TUE JUN 18 2013

.DISCUSSION...
18Z TAF ISSUANCE.

&&

.AVIATION...
SCT SHRA/TSRA ONGOING ACROSS C LA THRU SE TX/SW LA THIS
MORNING...ENHANCED BY AN APPROACHING SHORTWAVE/MVC OVER N TX. WITH
THE COVERAGE EXPECTED TO INCREASE...WILL KEEP VCTS AND TEMPO
GROUPS FOR SHRA/TSRA & MVFR VSBY/CEILING THRU THE AFTERNOON HOURS
IN ALL TERMINALS. ACTIVITY EXPECTED TO DIMINISH AFTER 00Z THIS
EVENING...WITH MAINLY VRB WINDS 5 KTS OR LESS.

DML

&&

.PREV DISCUSSION... /ISSUED 1025 AM CDT TUE JUN 18 2013/

DISCUSSION...
INCREASED THE RAIN CHANCES SLIGHTLY FOR THIS AFTERNOON.
OTHERWISE...THE ZONE PACKAGE IS ON TARGET.

PREV DISCUSSION... /ISSUED 608 AM CDT TUE JUN 18 2013/

DISCUSSION...
FOR THE 12Z TAF PACKAGE.

AVIATION...
PRIMARY CONCERN TODAY WILL BE INCREASING CONVECTIVE CHANCES AS
MID/UPPER RIDGE TO THE SOUTH CONTINUES TO WEAKEN. THIS WILL ALLOW
A WEAK FRONTAL BOUNDARY AND ITS ASSOCIATED MOISTURE POOL TO SAG
SOUTHWARD...WHILE A SHORTWAVE TROF CURRENTLY OVER CENTRAL TX
TRANSLATES EAST. ISOLATED LIGHT STREAMER TYPE SHOWERS CURRENTLY OVER
THE COASTAL WATERS AND ADJACENT COUNTIES/PARISHES...WHILE MORE
ROBUST CONVECTION IS ONGOING ACROSS NE TX/N LA. VFR IS EXPECTED TO
GENERALLY PREVAIL AT ALL TERMINALS TODAY...WITH THE GREATEST
PROBABILITY OF SHOWERS/THUNDERSTORMS EXPECTED OVER CENTRAL
LOUISIANA. KEPT THE GENERAL THEME OF THE PREVIOUS FORECAST...WITH
VICINITY AT THE COASTAL TERMINALS...AND TEMPO/PROB AT KAEX...BUT
DID INSERT THUNDER RATHER THAN JUST SHOWERS....AND EXTENDED IT
INTO THE EARLY EVENING HOURS.

13

PREV DISCUSSION... /ISSUED 500 AM CDT TUE JUN 18 2013/

SYNOPSIS...
REGIONAL RADAR MOSAIC SHOWS NUMRS SHOWERS AND THUNDERSTORMS N AND
W OF THE AREA...EXTENDING FM CNTL MS WEST ALONG THE I-20 CORRIDOR
TOWARD DALLAS-FORT WORTH WITH ADDITIONAL ACTIVITY EXTENDING SOUTH
ACRS THE HILL COUNTRY OF CNTL TX. THIS CONVECTION WAS ASSOCIATED
WITH A WEAK FRONT THAT EXTENDS FM NR MEMPHIS SW TO WACO AND
AUGMENTED BY ENERGY PROVIDED BY A VORT MAX TRAVELING THROUGH
WESTERLIES ALOFT. LATEST WATER VAPOR AND UPPER AIR ANALYSIS SHOW
THE PREVAILING WESTERLY FLOW ON THE NRN EDGE OF A HIGH PRES RIDGE
ORIENTED FM THE ERN PAC EAST ACRS THE RIO GRANDE VALLEY INTO THE
WRN GULF OF MEXICO. FURTHER SE...MOISTURE FM TD2 IS SPREADING OVER
THE YUCATAN PENINSULA INTO THE SRN GULF. THE DEPRESSION...WHICH
RECENTLY MOVED INLAND ACRS NRN GUATEMALA...IS NOT EXPECTED TO
IMPACT OUR AREA.

DISCUSSION...
UNSETTLED WEATHER WILL AFFECT THE AREA TODAY AND WEDNESDAY AS SHORTWAVE
DISTURBANCES CONTINUE TO TRANSLATE THROUGH THE WESTERLIES ALOFT.
THE SFC FRONT WILL SAG SLOWLY SOUTH THROUGH TONIGHT...GRADUALLY
STALLING ACRS CNTL LA INTO E TX BY WEDNESDAY MORNING. THE ATMOSPHERE
REMAINS VERY MOIST WITH FCST SOUNDINGS SHOWING PW VALUES CLIMBING
TO NEAR 2 INCHES SOUTH OF THE BOUNDARY TODAY. THE COMBINATION OF A
MOIST UNSTABLE ATMOSPHERE...SFC FRONT/OUTFLOW BOUNDARIES AND
PASSING ENERGY ALOFT WILL PRODUCE SCT SHOWERS AND THUNDERSTORMS
TODAY WITH THE HIGHEST CHANCES EXPECTED ACRS CNTL LA. STORMS ARE
NOT EXPECTED TO REACH SEVERE LIMITS...BUT A FEW STRONG STORMS
CAPABLE OF PRODUCING GUSTY WINDS WILL BE POSSIBLE. ACTIVITY WILL
WIND DOWN DURING THE EVENING WITH THE LOSS OF DAYTIME
HEATING...BUT AT LEAST A SLT CHC OF SHOWERS OR STORMS WILL
CONTINUE OVERNIGHT WITH POPS INCREASING TO CHC AGAIN DURING THE
DAY WEDNESDAY AS ANOTHER SHORTWAVE CROSSES THE AREA. MORE
WIDESPREAD CLOUD COVER AND SCT SHOWERS WILL RESULT IN AFTN HIGHS
TODAY AND WEDNESDAY AROUND OR SLIGHTLY BELOW NORMAL.

THURSDAY INTO FRIDAY...POPS TAPER BACK TO A DIURNAL SLT CHC AS
RIDGING ALOFT BEGINS TO BUILD BACK EAST ACRS TX INTO WRN LA WITH
AFTN HIGHS CLIMBING BACK TOWARD THE LOWER AND MIDDLE 90S. GLOBAL
MODELS TO VARYING DEGREES CONTINUE TO SHOW A WEAKNESS OR INVERTED
TROF RETROGRADING WEST ACRS THE GULF BENEATH THE UPPER RIDGE.
THIS WILL LEAD TO AN INCREASE IN RAIN CHANCES OVER THE WEEKEND AND
INTO EARLY NEXT WEEK.

MARINE...
THE BERMUDA HIGH PRESSURE SYSTEM WILL REMAIN IN PLACE OVER THE
GULF OF MEXICO OVER THE NEXT SEVERAL DAYS...RESULTING IN MOSTLY
LIGHT SOUTH TO SOUTHWEST WINDS AND LOW SEAS.

&&

.PRELIMINARY POINT TEMPS/POPS...
KLCH  77  90  75  92  76 /  20  30  10  20  10
KBPT  76  91  76  92  76 /  20  30  10  20  10
KAEX  72  91  73  94  74 /  30  40  10  20  10
KLFT  75  90  75  93  75 /  30  30  20  20  10

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&

$$