MESOSCALE DISCUSSION 2064
   NWS STORM PREDICTION CENTER NORMAN OK
   0908 AM CST SAT DEC 26 2015

   AREAS AFFECTED...NORTHWEST AND NORTHERN MIDDLE TN AND SOUTHWEST KY

   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

   VALID 261508Z - 261715Z

   PROBABILITY OF WATCH ISSUANCE...20 PERCENT

   SUMMARY...LOCALLY STRONG WIND GUSTS AND/OR A TORNADO CANNOT BE RULED
   OUT ACROSS NORTHWEST AND NORTHERN-MIDDLE TN INTO ADJACENT PARTS OF
   SOUTHWEST KY THIS MORNING.  GIVEN THE POTENTIAL FOR LOW COVERAGE OF
   STRONG OR SEVERE STORMS ACROSS THE DISCUSSION AREA...AN WATCH IS NOT
   WARRANTED AT THIS TIME.  HOWEVER...CONVECTIVE TRENDS WILL BE
   MONITORED FOR THIS REGION.

   DISCUSSION...AT 1435Z...MOSAIC AND MEMPHIS WSR-88D IMAGERY INDICATED
   A SMALL BOWING LINE OF STORMS LOCATED IN EXTREME NORTHEAST AR AND
   THE ADJACENT PORTION OF THE SOUTHEAST MO BOOTHEEL...WITH THE LINE
   MOVING TO THE EAST-NORTHEAST AT 35-40 KT.  SURFACE STREAMLINE
   ANALYSES AND OBSERVATIONS SHOWED A WARM FRONT ADVANCING TO THE NORTH
   ACROSS WESTERN TN THIS MORNING...WITH THE BOWING LINE OF STORMS
   APPEARING TO BE NEAR OR JUST SOUTH OF THE FRONT.  THESE OBSERVATIONS
   COMBINED WITH 40-50-KT SSWLY LOW-LEVEL WINDS JUST OFF THE SURFACE
   PER THE MEMPHIS VWP DATA SUGGEST A THREAT FOR DAMAGING WINDS WITH
   THIS BAND OF STORMS.  IN ADDITION...THE SAME VWP DATA INDICATED
   STRONG SURFACE-1 KM SHEAR OF 35 KT AND 0-1 KM SRH AROUND 365 M2/S2. 
   THIS SHEAR AND THE LEWP STRUCTURE IN THE BOWING LINE WITH THE
   POTENTIAL FOR THIS ACTIVITY TO BE SURFACE BASED...A TORNADO THREAT
   CANNOT BE RULED OUT AS THE STORMS MOVE THROUGH NORTHWEST TN TO FAR
   SOUTHWEST KY THIS MORNING.

   FORECAST HEIGHT RISES ACROSS THIS REGION THROUGH EARLY AFTERNOON AND
   APPARENT LACK OF LARGER SCALE FORCING ARE A NEGATIVE FACTOR FOR AN
   INCREASE IN STORM COVERAGE.  HOWEVER...RECENT RAP AND 00Z ECMWF/06Z
   NAM SUGGEST A WEAK IMPULSE MAY BE TRACKING TO THE NORTHEAST ACROSS
   THE DISCUSSION AREA THIS MORNING AND CONTRIBUTING TO SOME UPWARD
   VERTICAL MOTION.  THIS LOCALIZED FORCING MAY ALLOW THE ONGOING
   STORMS TO PERSIST WITH SOME SEVERE THREAT SPREADING ACROSS NORTHWEST
   TN INTO SOUTHWEST KY.  HOWEVER...THIS LOCALIZED FORCING MAY SUPPORT
   AN ISOLATED SEVERE THREAT SPREADING ACROSS NORTHWEST TN INTO
   SOUTHWEST KY THIS MORNING.

   ..PETERS/MEAD.. 12/26/2015


   ATTN...WFO...LMK...OHX...PAH...MEG...

   LAT...LON   36228948 37028810 37468631 37168602 36518612 36068641
               35718756 35468857 35448929 35448983 36228948