Lake Wind Advisory 27, NWS Shreveport, LA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
945 PM CDT MON AUG 27 2012

.DISCUSSION...
MOST OF THE SHOWER AND ISOLATED THUNDERSTORMS WILL CONTINUE TO
DIMINISH...BUT THERE IS A WEAK BOUNDARY OF SORTS ALONG AND NORTH
OF I-30 AND RADAR STILL SHOWING THE LIONS SHARE OF ACTIVITY IN THE
CORRIDOR. WE HAVE DECIDED TO LEAVE SLIGHT CHANCE POPS IN
OVERNIGHT. NO CHANGES TO LOW OR DEW POINTS WHICH ALL SEEM TO BE
RIGHT ON TRACK. DID UPDATE THE WINDS DIRECTIONS OFF THE MARK IN
MAINLY EAST TEXAS. LOADED IN LAPS AND NEW NAM THROUGH 12Z. WE WILL
BE SENDING A NEW SUITE OF PRODUCTS SHORTLY. AS FAR AS ISSAC GOES
THE OUTFLOW IS TORN APART AND STRETCHED IN OVER TEXAS. THE STORM
MID AND LOW LEVELS LIKEWISE LACK SYMMETRY AND REMAINS ELONGATED
DUE TO THE SURGING OUTFLOW OVER TEXAS. THE NE QUAD OF THE STORM
CONTINUES TO LACK CENTRAL DENSE OVERCAST OR ANY GOOD CIRRUS
FINGERS OBVIOUSLY WITH SOME OF THE BANDS OVER FLORIDA SUSTAINED BY
SEA BREEZE AND HEATING. THE OUTFLOW HERE IS NEARLY DIVERGENT
TOWARD THE NE GULF COAST AND IS THE LIKELY REASON FOR THE STORM
BEING UNABLE TO WRAP UP TIGHTER. WE WILL CONTINUE TO MONITOR FOR
CHANGES IN THE STORMS PATH AND EXPECTED AFFECTS IN OUR CWA. /24/

&&

.AVIATION...
SOME ISOLATED SHOWER ACTIVITY STILL LINGERS IN NORTHEAST THIS
EVENING...BUT THIS ACTIVITY SHOULD DISSIPATE WITHIN AN HOUR. VFR
FLIGHT CATEGORIES WILL CONTINUE TO BE OBSERVED OVERNIGHT...WITH SOME
MID AND HIGH LEVEL CLOUDINESS OBSERVED. LOCALIZED PATCHY FOG WILL BE
POSSIBLE AFTER 06Z THROUGH 14Z TUESDAY...ANY ASSOCIATED TEMPO IFR
VISIBILITIES AT TERMINALS WILL BE HANDLED WITH AMD. LIGHT AND
VARIABLE WINDS WILL PERSIST THROUGH 12Z...WITH LIGHT NORTHERLY WINDS
BECOMING COMMON THEREAFTER. /11/

&&

.PREV DISCUSSION... /ISSUED 308 PM CDT MON AUG 27 2012/

DISCUSSION...
DRIER AIR BEGINNING TO WORK INTO THE MID LVLS AS NE FLOW ALOFT HAS
BEGUN TO INCREASE IN RESPONSE TO SLOW APPROACHING T.S ISAAC OVER
THE CENTRAL GULF. PW VALUES DROPPED FROM THE 12Z SOUNDINGS...TO
THE SPECIAL 18Z SOUNDING LAUNCHES. HOWEVER...ISOLD CONVECTION
DEVELOPED ACROSS MOST OF AREA AROUND MIDDAY AS MID LVL SHEAR
INCREASED IN ASSOCIATION WITH THESE INCREASED MID LVL WINDS.
EXPECT CONVECTION TO DIMINISH WITH SUNSET...AND SUBSIDENCE TO BE
INCREASED DURG DAYTIME TUE...DIMINISHING CONVECTION.
THEREAFTER...POPS WILL INCREASE OVER NORTHCENTRAL LA WITH
PROJECTED PATH OF ISAAC...BUT WITH THE HEAVY QPF LIKELY JUST
MISSING CWA TO THE SOUTH AND EAST. WILL KEEP LIKELY POPS WITH ISOLD
TSTMS CLOSER TO THE STORM PATH AFTER IT MAKES LANDFALL LATE TUE
NIGHT. HOWEVER...ISAAC REMAINS SOMEWHAT DISORGANISED...MAKING EXACT
TRACK DIFFICULT TO PIN DOWN...WITH SHAPE ELONGATED...AND LACK OF
WELL DEFINED EYE ON SATELLITE. BOUY PRESSURE DATA EARLIER THIS
AFTN SUGGESTED DEEPENING TRENDS WERE OCCURRING AS EXPECTED.
HAVE LOWERED DEWPOINTS SLIGHTLY TO ACCOUNT FOR ADVECTION TO THE SW
OF DEWPONTS OVER CENTRAL AND NORTHERN MS...LOWER TO MID 60S.
DAYTIME HIGHS WERE LOWERED ACCORDINGLY WHERE POPS ARE
LIKELY...DOWN TO AROUND MID 80S./VII/.

AVIATION...
MOSTLY VFR FLIGHT WEATHER FOR THE REMAINDER THIS AFTERNOON AND
EVENING. EXCEPTION WILL BE IN AND AROUND SCATTERED SHOWERS AND
THUNDERSTORMS WHERE BRIEF PERIODS OF IFR CIGS AND VISIBILITY MAY
OCCUR. WIND GUST TO 35 KTS WITH MODERATE TO SEVERE TURBULENCE CAN BE
EXPECTED NEAR THE STRONGER CONVECTION...WHICH WILL BE MAINLY OVER
PORTIONS OF EAST TEXAS BETWEEN KTYR AND KLFK. AFTER 06Z TONIGHT
THROUGH 14Z MONDAY...EXPECT LOCALIZED AREAS OF IFR VISIBILITY...
BRIEFLY 1 TO 3 MILES IN FOG...MAINLY AT LOCATIONS WHICH RECEIVE RAIN
THIS AFTERNOON AND EVENING. /14/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  73  95  71  91  73 /  10  20  20  30  40
MLU  72  93  71  86  74 /  10  20  40  60  60
DEQ  72  94  68  94  71 /  20  10  10  10  10
TXK  73  93  70  92  72 /  10  10  10  20  20
ELD  71  94  71  91  73 /  10  20  20  30  40
TYR  73  94  69  95  72 /  20  10  10  20  10
GGG  72  94  70  93  73 /  10  20  20  20  20
LFK  73  94  71  92  74 /  10  20  20  30  20

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&

24/11

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SHREVEPORT LA
1157 AM CDT MON AUG 27 2012

ARZ050-051-059>061-070>073-LAZ001>006-010>014-017>022-OKZ077-
TXZ096-097-108>112-124>126-136>138-149>153-165>167-281700-
SEVIER-HOWARD-LITTLE RIVER-HEMPSTEAD-NEVADA-MILLER-LAFAYETTE-
COLUMBIA-UNION AR-CADDO-BOSSIER-WEBSTER-CLAIBORNE-LINCOLN-
UNION LA-DE SOTO-RED RIVER-BIENVILLE-JACKSON-OUACHITA-SABINE LA-
NATCHITOCHES-WINN-GRANT-CALDWELL-LA SALLE-MCCURTAIN-BOWIE-
FRANKLIN-TITUS-CAMP-MORRIS-CASS-WOOD-UPSHUR-MARION-SMITH-GREGG-
HARRISON-CHEROKEE-RUSK-PANOLA-NACOGDOCHES-SHELBY-ANGELINA-
SAN AUGUSTINE-SABINE TX-
1157 AM CDT MON AUG 27 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
ARKANSAS...SOUTHWEST ARKANSAS...NORTH CENTRAL LOUISIANA...
NORTHWEST LOUISIANA...SOUTHEAST OKLAHOMA...EAST TEXAS AND
NORTHEAST TEXAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT...

ISOLATED SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF NORTHEAST
TEXAS...MAY INCREASE DURING THE AFTERNOON. ELSEWHERE...SHOWERS AND
THUNDERSTORMS WILL REMAIN VERY ISOLATED. ALTHOUGH NO SEVERE
WEATHER IS EXPECTED...CLOUD TO GROUND LIGHTNING...AND BRIEF HEAVY
RAINFALL...MAY OCCUR IN STRONGER STORMS. THIS ACTIVITY WILL LIKELY
DIMINISH BY AROUND SUNSET.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...

TROPICAL STORM ISAAC WILL MOVE NORTH ACROSS PORTIONS OF SOUTHEAST
LOUISIANA AND MISSISSIPPI ON WEDNESDAY AND THURSDAY. GUSTY WINDS
AND BRIEF HEAVY RAINFALL MAY BE POSSIBLE ACROSS NORTH LOUISIANA
AND SOUTHERN ARKANSAS AS THIS STORM LIFTS NORTH. EMERGENCY
MANAGEMENT OFFICIALS SHOULD CONTINUE TO MONITOR STATEMENTS FROM
THE NATIONAL WEATHER SERVICE REGARDING ANY CHANGES TO THE
FORECAST TRACK OR INTENSITY OVER THE NEXT SEVERAL DAYS.

.SPOTTER INFORMATION STATEMENT...

ACTIVATION OF EMERGENCY MANAGEMENT PERSONNEL...AMATEUR RADIO
OPERATORS...AND STORM SPOTTERS WILL NOT BE NEEDED TODAY OR
TONIGHT.

VII