Severe Thunderstorm Warning 31, NWS Shreveport, LA

AREA FORECAST DISCUSSION...CORRECTED THE LOWS AND HIGHS
NATIONAL WEATHER SERVICE SHREVEPORT LA
300 AM CDT WED APR 11 2001

FOR THE COUNTY WARNING/FORECAST AREA THIS FORECAST WILL BE
A LITTLE COMPLICATED. PROBLEM FOR THE SHORT TERM IS WHERE
THE CHANCE OF RAIN AND THUNDERSTORMS WILL BE AND WHEN THEY WILL
END...PERIOD OF NO OR SLIGHT CHANCES...THEN RETURN DEVELOPMENT.
ALSO LOCATIONS OF POSSIBLE SEVERE MENTION FOR TODAY AND THEN
AGAIN ON THURSDAY. THIS IS DUE MAINLY TO THE MOVEMENT OF
SURFACE LOW PRESSURE SYSTEM TO THE NORTH OF THE FORECAST AREA
...OVER THE PLAINS AND INTO THE GREAT LAKES REGION...WITH A
TRAILING COLD FRONT. THE FACT THAT THE FRONT AFTER MOVING INTO
PART OF THE REGION TODAY...BECOMING STATIONARY OVER THE AREA
TONIGHT...AND THEN RETREATS SLOWLY NORTH LATE THURSDAY AND
THURSDAY NIGHT.

SINCE THE UPPER LOW ASSOCIATED WITH THE SURFACE SYSTEM
LIFTS FROM THE PLAINS TODAY TOWARD THE GREAT LAKES REGION
ON THURSDAY...MOST OF THE ENERGY WITH THE SYSTEM ALSO
MOVES TO THE NORTH OF THE COUNTY WARNING AREA AND ALLOWS
SLOWER MOVEMENT OF THE SURFACE SYSTEM...WHICH WILL ALLOW
IT TO BECOME STATIONARY. THE UPPER SYSTEM MOVING UP THE
RIDGE TENDS TO FLATTEN THE RIDGE AND ALLOWS THE UPPER FLOW
TO BECOME MORE ZONAL IN NATURE WITH A CONTINUED SOUTHWEST FLOW
WITH SEVERAL SMALL SCALE DISTURBANCES MOVING OVER THE REIGON.
THESE WILL AID IN THE DEVELOPMENT OF THUNDERSTORMS THROUGH
LATE WEEK AND INTO THE WEEKEND.

MODEL OF CHOICE IS THE AVN AND MIX OF THE ETA. LIKE THE CONTINUED
CHANCE OF PRECIPITATION IN THE MAV MOS.  THE FRONT WILL MOVE INTO
ZONES TODAY WITH BAND OF SHOWERS AND THUNDERSTORMS...POSSIBLY
PRECEEDED BY LIGHT RAIN. WE HAVE ALREADY HAD LIGHT RAIN DURING
THE NIGHT AND THIS WAS IN REGION OF NEGATIVE VORTICITY ADVECTION.
RICH LOW LEVEL MOISTURE PRESENT AND APPROACHING POSITIVE
VORTICITY ADVECTION HEADED OUR WAY EARLY THIR MORNING...AND
CURRENTLY FEEL THAT LIGHT RAIN WILL PRECEED THE FRONT...FOLLOWED BY
THUNDERSTORMS ALONG AND NEAR THE FRONT. MODELS SHOW THAT
UPPER LEVEL SUPPORT FOR SEVERE THUNDERSTORMS WILL HOWEVER SHIFT TO
THE NORTHWEST SECTIONS OF THE COUNTY WARNING AREA AND TO THE
SOUTHWEST OF THE REGION TODAY...WITH ACTIVITY DECREASING OVER THE
CENTRAL AND SOUTHERN SECTIONS AS THEY MOVE OVER REGION WITH
MOST UNSTABLE AREAS OFF TO THE NORTHEAST BY TONIGHT AND DOWN
TO ALONG THE UPPER TEXAS COAST. LIFTED INDEX VALES AND K
INDEX VALUES ALONG THE FRONT PLACE MOST OF THE AREA IN ONLY UNSTABLE
TO MODERATLY UNSTABLE REGION. CAPE VALUES DROP TO LESS THAN 1000 J/KG
WHICH ALSO PLACES US IN LOW CATAGORY.  FOR TONIGHT MOST ACTIVITY WILL
BE OVER WITH WITH A RETURN ON THE DAY THURSDAY OVER NORTH LOUISIANA
INTO SOUTH ARKANSAS AND INTO THURSDAY NIGHT. LIFTED INDEX AND CAPE
VALUES THEN RISE INTO MODERATE RANGE INTO AFTERNOON THURSDAY.
HENCE WILL INCLUDE MENTION OF POSSIBLY SEVERE THUNDERSTORMS
THIS REGION ON THURSDAY.

WINDS WILL BE HIGH FOR TODAY AND WILL CONTINUE LAKE WIND ADVISORIES.
DROPPING OFF FOR REMAINING SHORT TERM.

06

SHV 082/066 081/066 084 5143
MLU 084/066 082/066 086 4353
TXK 078/057 079/063 085 6124
TYR 081/059 080/064 084 6122
LFK 084/069 083/066 086 4231

.SHV...NONE.