MESO: Mesoscale Discussion 2399

ACUS11 KWNS 282333
SWOMCD
SPC MCD 282333
LAZ000-MSZ000-TXZ000-290030-

MESOSCALE DISCUSSION 2399
NWS STORM PREDICTION CENTER NORMAN OK
0533 PM CST FRI NOV 28 2008

AREAS AFFECTED...E/SE TX INTO CENTRAL LA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 282333Z - 290030Z

ISOLATED TORNADO THREAT WILL BE POSSIBLE THROUGH THE EVENING FROM
PARTS OF E/SE TX THROUGH CENTRAL LA ALONG A SLOW SWD MOVING
BOUNDARY. TORNADO WATCH MAY BE NEEDED IF TRENDS SUGGEST TSTM
COVERAGE WILL INCREASE.

A SLOW SWD MOVING FRONT EXTENDED FROM CENTRAL AL WSWWD THROUGH SRN
MS AND CENTRAL LA TO E CENTRAL/SE TX. AIR MASS IS MODERATELY
UNSTABLE /MLCAPE 500-1000 J/KG/ FROM SE TX INTO CENTRAL/SRN LA.
ALTHOUGH BOUNDARY LAYER SHOULD COOL SOME WITH LOSS OF DAYTIME
HEATING...A CONTINUED INFLUX OF MOISTURE INTO AREA S OF THE FRONT
SUGGESTS AT LEAST MARGINAL INSTABILITY WILL BE MAINTAINED THROUGH
THE EVENING. EFFECTIVE BULK SHEAR /35-50 KT/ REMAINS SUFFICIENT FOR
UPDRAFT ROTATION WITH REGIONAL RADARS INDICATING A PERSISTENT
ROTATION COUPLET WITH THE STORM TRACKING FROM SABINE COUNTY TX INTO
SABINE PARISH LA. ALTHOUGH INSTABILITY WILL BE MARGINAL THROUGH THE
EVENING...ANY STORMS DEVELOPING AND/OR TRACKING ALONG THE SURFACE
FRONT MAY HAVE AN ENHANCED TORNADO THREAT GIVEN GREATER LIKELIHOOD
FOR MORE FAVORABLE LOW LEVEL SHEAR NEAR THE BOUNDARY.

AN ADDITIONAL THREAT FOR GREATER HODOGRAPH CURVATURE MAY DEVELOP
THROUGH THE EVENING AS A SWLY LLJ STRENGTHENS. THE CURRENT THREAT
FOR ISOLATED TORNADOES WILL CONTINUE TO BE MONITORED FOR A POTENTIAL
WW...AS WILL THE POTENTIAL FOR AN INCREASED TORNADO THREAT LATER
THIS EVENING ALONG THE LLJ AXIS.

..PETERS.. 11/28/2008

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...JAN...LIX...LCH...SHV...

LAT...LON 31139002 30509105 30369296 30449430 30939431 31439397
31549314 31549081 31139002

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.