MESOSCALE DISCUSSION 0484
   NWS STORM PREDICTION CENTER NORMAN OK
   0655 PM CDT TUE APR 29 2014

   AREAS AFFECTED...CNTRL AND NRN AL AND A SMALL PART OF SRN MIDDLE TN

   CONCERNING...TORNADO WATCH 118...

   VALID 292355Z - 300130Z

   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 118 CONTINUES.

   SUMMARY...WHILE THE THREAT FOR AN ISOLATED TORNADO AND SOME HAIL MAY
   PERSIST ANOTHER COUPLE HOURS OR SO ACROSS CNTRL AND NRN AL...THE
   OVERALL SEVERE THREAT APPEARS MARGINAL.

   DISCUSSION...EARLY THIS EVENING AN EXTENSIVE OUTFLOW BOUNDARY
   STRETCHES FROM THE NRN GULF NWD THROUGH ERN MS THEN NEWD INTO MIDDLE
   TN. STORMS THAT INITIATED FARTHER WEST OVER NRN MS ALONG PACIFIC
   FRONT WEAKENED CONSIDERABLY AS THEY CROSSED INTO THE LESS UNSTABLE
   REGIME OVER NRN AL EAST OF THE OUTFLOW BOUNDARY WHERE SFC DEWPOINTS
   ARE ONLY IN THE LOW 60S. MOREOVER...CONSIDERABLE ANVIL DEBRIS HAS
   RESULTED IN VERY LIMITED BOUNDARY LAYER WARMING. ONSET OF NOCTURNAL
   COOLING WILL FURTHER LIMIT ANY FUTURE DESTABILIZATION POTENTIAL. NEW
   STORMS ARE DEVELOPING OVER NWRN AL...AND VWPS FROM BIRMINGHAM AND
   HUNTSVILLE INDICATE 50+ KT 0-6 KM SHEAR...SUGGESTING SOME STORMS
   COULD STILL TAKE ON SUPERCELL STRUCTURES. MOREOVER...AN INCREASE IN
   THE LLJ WILL CONTRIBUTE TO MORE FAVORABLE 0-1 KM HODOGRAPHS FOR
   LOW-LEVEL MESOCYCLONES THIS EVENING. DESPITE THE FAVORABLE
   KINEMATICS FOR ORGANIZED STORMS...THE MARGINAL THERMODYNAMIC
   ENVIRONMENT WILL PROBABLY REMAIN A LIMITING FACTOR FOR A MORE ROBUST
   SEVERE THREAT.

   ..DIAL.. 04/29/2014


   ATTN...WFO...OHX...BMX...HUN...

   LAT...LON   34238803 35328638 34828569 33468577 32968688 32518811
               34238803