National Weather Service Raw Text Product

423 
ACUS11 KWNS 060053
SWOMCD
SPC MCD 060053 
GAZ000-ALZ000-TNZ000-MSZ000-060300-

MESOSCALE DISCUSSION 0775
NWS STORM PREDICTION CENTER NORMAN OK
0753 PM CDT MON MAY 05 2003

AREAS AFFECTED...SRN AR...NRN MS...NRN AL...NRN GA

CONCERNING...TORNADO WATCH 255...256...

VALID 060053Z - 060300Z

NEW WW REPLACING WWS 255 AND 256 WILL LIKELY BE NEEDED WITHIN THE
NEXT HOUR OR SO ACROSS PARTS OF NORTHERN MISSISSIPPI/ALABAMA...
PERHAPS NORTHWEST GEORGIA.

MID-LEVEL SHORT WAVE/JET STREAK...EMBEDDED WITHIN STRONG WEST
SOUTHWESTERLY UPPER FLOW REGIME...HAS BEEN READILY EVIDENT IN LATEST
WATER VAPOR LOOPS MIGRATING ACROSS SOUTHERN ARKANSAS.  LARGE -SCALE
FORCING ASSOCIATED WITH THIS FEATURE CONTINUES TO AID EVOLUTION OF
MESOSCALE CONVECTIVE SYSTEM...NORTH/NORTHWEST OF
GREENVILLE/GREENWOOD MS...WHERE  BROAD LOW/MID-LEVEL CIRCULATION HAS
BECOME EVIDENT IN REGIONAL RADAR LOOPS AND SURFACE DATA.  ACTIVITY
APPEARS TO BE MOSTLY ROOTED IN MOIST LAYER ABOVE SURFACE COLD POOL
ASSOCIATED WITH PRIOR CONVECTION...BUT CAPE ON THE ORDER OF 1500 TO
3000 J/KG IS SUPPORTING VIGOROUS UPDRAFTS.

AIDED BY STRONG VERTICAL SHEAR PROFILES IN CLOUD BEARING
LAYER...CONVECTION WILL LIKELY CONTINUE TO ORGANIZE.  THERMODYNAMIC
STRUCTURE WITH RELATIVE DRY MID-LEVEL ENVIRONMENT EVIDENT IN 06/00Z
SOUNDING FROM JACKSON MS SUGGESTS DEVELOPMENT OF ANOTHER STRONG
SURFACE COLD POOL IS POSSIBLE DURING THE NEXT COUPLE OF HOURS.	40
TO 50 KT WESTERLY MEAN ENVIRONMENTAL FLOW WILL AID PROPAGATION OF
COLD POOL ALONG WEAK SURFACE BOUNDARY INTO AREAS NEAR/NORTH OF
BIRMINGHAM/ATLANTA BY 06/06Z...ACCOMPANIED BY POTENTIALLY DAMAGING
WINDS ALONG GUST FRONT.

..KERR.. 05/06/2003

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

ATTN...WFO...MRX...FFC...OHX...BMX...HUN...MEG...JAN...

34348973 34978884 35028707 35028572 34508456 33918427
33308483 33208599 33468721 33458814 33408910 33488974