Severe Thunderstorm Warning 201, NWS Shreveport, LA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
349 PM CDT TUE APR 8 2008

.DISCUSSION...

.DISCUSSION...
CONVECTION ACROSS THE NORTHERN SECTIONS OF THE CWA...MAINLY ALONG
AND NORTH OF THE INTERSTATE 30 CORRIDOR WILL CONTINUE INTO THE
EVENING. INCREASING LOW LEVEL INSTABILITY COMBINED WITH A SLOW
MOVING SURFACE FRONT...HIGH DEWPOINTS AND OTHER FACTORS MAY LEAD
TO A FEW SEVERE STORMS...AT LEAST FOR THE EARLY PORTION OF THE
EVENING. HEAVY RAIN IS ALSO POSSIBLE...WITH SOME TRAINING ALONG THE
SLOW MOVING FRONT. WIDESPREAD FLOODING COULD BE A PROBLEM IF THE
FRONT STALLS...AND CONVECTION CONTINUES TO INITIATE ALONG FRONT.
BUT...NOT LOOKING FOR THIS TO HAPPEN TONIGHT...SO HAVE DECIDED
NOT TO ISSUE A FLASH FLOOD WATCH. HOWEVER...SHORT DURATION FLASH
FLOODING IN A SMALL AREA CAN OCCUR WITH ANY THUNDERSTORM...AND
THIS IS POSSIBLE NORTH AND WEST OF A EL DORADO...SHREVEPORT...NACOGDOCHES
LINE...AND CAN BE HANDELED WITH WARNINGS AS NEEDED.  MODELS
INDICATE FRONT WILL STALL SOMEWHERE SOUTH OF INTERSTATE 20 BY
MORNING...THEN MOVE NORTH OF THE CWA IN THE AFTERNOON. THIS WILL
PLACE ALL THE AREA BACK IN A MOIST AND HIGHLY UNSTABLE ENVIRONMENT...
BUT THE FOCUS OF WEDNESDAY NIGHTS PRECIPITATION WILL BE ACROSS
CENTRAL OKLAHOMA IN VICITY OF SURFACE BOUNDARY. IF THE FRONT DOES
NOT MOVE AS FAR NORTH AS FORECAST...A FLASH FLOOD WATCH WILL BE IN
ORDER FOR AREAS ALONG AND JUST NORTH OF THE BOUNDARY. ON THURSDAY...
UPPER LOW WILL MOVE EAST INTO THE CENTRAL PLAINS...AND THIS WILL
DRIVE DRY AIR AND A SURFACE FRONT WELL INTO TEXAS. LOOK FOR A
LINE OF CONVECTION TO DEVELOP THURSDAY AFTERNOON AND CROSS THE CWA
THURSDAY NIGHT. THIS SHOULD BE THE LAST FROM THIS SYSTEM...WITH
DRY AIR SPILLING INTO THE REGION...JUST IN TIME FOR THE WEEKEND.
DRY FORECAST TO CONTINUE INTO EARLY NEXT WEEK AS A STRONG UPPER
RIDGE BECOMES ANCHORED FROM WEST TEXAS...NORTHWARD TO THE CANADIAN
BORDER.

&&

.AVIATION...
SURFACE MAP CONTINUES TO SHOW A FRONT DRAPED FROM THE METROPLEX INTO
SW MO...WITH A SURFACE LOW SW OF KSGF.  TSRA CONTINUE TO DEVELOP
THIS AFTERNOON W OF A KTYR-KBLR LINE AS SHORTWAVE TROUGH EJECTS INTO
MID-MISSISSIPPI VALLEY.  OCCASIONAL TSRA MAY BE SEEN UNTIL A COUPLE
OF HOURS AFTER SUNSET...ESPECIALLY OVER NW PARTS OF THE FORECAST
AREA.

FRONT MAY MEANDER A LITTLE N TONIGHT.  ISENTROPIC FORCING AND WEAK
PERTURBATIONS RIDING THE FRONT MAY RESULT IN ADDITIONAL SHRA/TSRA
DEVELOPMENT BY 09/0600 UTC...MAINLY N OF IH-30...WHERE MVFR/IFR
FLIGHT CATEGORIES MAY BE SEEN.  REGARDLESS...IFR FLIGHT CATEGORIES
DUE TO CIGS WILL LIKELY BE SEEN CLOSE TO SUNRISE...ESPECIALLY AT ANY
TERMINALS WHICH RECEIVED SHRA/TSRA DURING THE EVENING.

MORE SHORTWAVE ENERGY EMBEDDED IN THE SW FLOW ALOFT MAY AID IN
ADDITIONAL CONVECTIVE DEVELOPMENT BEFORE 09/1800 UTC.  I EXPECT MOST
OF THE TSRA COVERAGE TO INCREASE AFTER 10/0000 UTC...AS THE MAIN
SHORTWAVE TROUGH STARTS TO EJECT INTO THE PLAINS.  /BUTTS/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  61  78  67  80 /  50  40  30  50
MLU  63  81  66  84 /  20  30  30  30
DEQ  57  69  65  77 /  70  60  50  70
TXK  60  72  66  79 /  70  50  40  70
ELD  61  75  66  81 /  50  40  30  60
TYR  63  79  68  79 /  60  40  40  50
GGG  62  78  69  78 /  50  40  40  60
LFK  66  83  69  83 /  20  20  20  50

&&

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

14/21

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SHREVEPORT LA
1200 PM CDT TUE APR 8 2008

ARZ050-051-059>061-070>073-LAZ001>006-010>014-017>022-OKZ077-TXZ096-
097-108>112-124>126-136>138-149>153-165>167-091100-
ANGELINA-BIENVILLE-BOSSIER-BOWIE-CADDO-CALDWELL-CAMP-CASS-CHEROKEE-
CLAIBORNE-COLUMBIA-DE SOTO-FRANKLIN-GRANT-GREGG-HARRISON-HEMPSTEAD-
HOWARD-JACKSON-LA SALLE-LAFAYETTE-LINCOLN-LITTLE RIVER-MARION-
MCCURTAIN-MILLER-MORRIS-NACOGDOCHES-NATCHITOCHES-NEVADA-OUACHITA-
PANOLA-RED RIVER LA-RED RIVER TX-RUSK-SABINE LA-SABINE TX-
SAN AUGUSTINE-SEVIER-SHELBY-SMITH-TITUS-UNION AR-UNION LA-UPSHUR-
WEBSTER-WINN-WOOD-
1200 PM CDT TUE APR 8 2008

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...TODAY AND TONIGHT...

THUNDERSTORMS WILL INCREASE IN COVERAGE AND INTENSITY ACROSS
SOUTHEAST OKLAHOMA...SOUTHWEST ARKANSAS AND NORTHEAST TEXAS
THIS AFTERNOON AND TONIGHT...AS A COLD FRONT MOVES INTO THE REGION.
A FEW STORMS MAY BECOME SEVERE. WITH COLD TEMPERATURES ALOFT...
LARGE HAIL IS THE PRIMARY CONCERN. ALSO...LOCALLY HEAVY RAINFALL
MAY RESULT IN FLASH FLOODING...ESPECIALLY AREAS NORTH OF
INTERSTATE 30.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY...

PERIODS OF VERY HEAVY RAINFALL MAY PRODUCE FLOODING...FROM WEDNESDAY
INTO EARLY FRIDAY...AS A WARM FRONT LIFTS NORTH ACROSS THE REGION.
THE WARM FRONT WILL BE FOLLOWED BY ANOTHER COLD FRONT...WHICH MAY
CONTRIBUTE TO SEVERE THUNDERSTORMS. LARGE HAIL...DAMAGING WINDS...AND
ISOLATED TORNADOES WILL BE POSSIBLE THURSDAY AND THURSDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

THE ACTIVATION OF STORM SPOTTER GROUPS...HAM RADIO OPERATORS...AND
EMERGENCY MANAGEMENT PERSONNEL...IN SUPPORT OF SEVERE WEATHER
OPERATIONS...MAY BE NEEDED LATER THIS AFTERNOON OR TONIGHT.