MESOSCALE DISCUSSION 2384
   NWS STORM PREDICTION CENTER NORMAN OK
   0135 AM CST WED DEC 21 2011
   
   AREAS AFFECTED...NERN MS/NWRN AL INTO PARTS OF MIDDLE TN
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 210735Z - 210900Z
   
   AN ISOLATED...BRIEF TORNADO AND/OR STRONG WIND GUST CANNOT BE RULED
   OUT FROM THE CONVECTION/EMBEDDED TSTMS MOVING NEWD ACROSS NERN MS
   INTO ADJACENT PARTS OF NWRN AL AND MIDDLE TN.  GIVEN THE LIMITED
   POTENTIAL FOR GREATER COVERAGE OF ORGANIZED STORMS DUE PRIMARILY TO
   WEAK INSTABILITY...A WW IS NOT WARRANTED AT THIS TIME.
   
   AT 0715Z...REGIONAL RADAR IMAGERY CONTINUED TO SHOW A CORRIDOR OF
   CONVECTION AND EMBEDDED TSTMS EXTENDING FROM NERN MS THROUGH W
   CENTRAL TN INTO SRN IND...OR FROM 40 E GWO TO 55 E MKL TO 20 NW BMG.
   WATER VAPOR IMAGERY SHOWED A CLOSED LOW CENTERED OVER NWRN MO WITH
   THE ATTENDANT TROUGH EXTENDING SWD INTO AR.  ALTHOUGH STRONGEST
   FORCING FOR ASCENT WITH THIS SYSTEM WILL REMAIN N OF THE DISCUSSION
   AREA...SOME HEIGHT FALLS AND MODERATE-STRONG SWLY MIDLEVEL WINDS
   WILL PROMOTE STORM ORGANIZATION AS INDICATED WITH ROTATIONAL
   COUPLETS OVER NERN MS PER RADAR IMAGERY.  DESPITE THE PRESENCE OF
   SOME ORGANIZED STORMS....THE POTENTIAL FOR AN ALREADY WEAKLY
   UNSTABLE AIR MASS TO FURTHER DESTABILIZE SUFFICIENTLY TO SUPPORT
   SURFACE BASED ACTIVITY IS FAIRLY LOW...GIVEN TIME OF DAY.  THUS...AS
   INDICATED...THE WEAK INSTABILITY AND SURFACE BASED INHIBITION WILL
   REMAIN THE LIMITING FACTORS FOR A GREATER SEVERE WEATHER THREAT
   DURING THE NEXT SEVERAL HOURS.  THE ONLY EXCEPTION TO THIS FORECAST
   IS ACROSS NERN MS AND ADJACENT PARTS OF NWRN AL AND TN WHERE SOME
   LOW LEVEL MOISTENING MAY PROVE SUFFICIENT TO ENHANCE THE WEAK
   DESTABILIZATION...AND COMBINED WITH STRONG DEEP LAYER AND LOW LEVEL
   SHEAR SUPPORT A BRIEF TORNADO.  DEEP LAYER SHEAR VECTORS ORIENTED
   ACROSS THE ZONE OF CONVECTION SUGGESTS THE POTENTIAL FOR CONTINUED
   DISCRETE ROTATING UPDRAFTS.  THIS THREAT WILL NEED TO BE
   MONITORED...ESPECIALLY WITH ANY LONGER-LIVED/SUSTAINED UPDRAFTS.
   
   ..PETERS.. 12/21/2011
   
   
   ATTN...WFO...OHX...BMX...HUN...MEG...JAN...
   
   LAT...LON   33568934 34458870 35128809 35698758 35608692 34058756
               33368815 33248902 33568934