ZCZC SPCSWOMCD ALL ACUS11 KWNS 290239 SPC MCD 290239 ALZ000-MSZ000-LAZ000-290415- MESOSCALE DISCUSSION 1836 NWS STORM PREDICTION CENTER NORMAN OK 0839 PM CST MON NOV 28 2016 AREAS AFFECTED...PORTIONS OF SOUTHERN MS...SOUTHWEST AL...SOUTHEAST LA CONCERNING...TORNADO WATCH 502 VALID 290239Z - 290415Z THE SEVERE WEATHER THREAT FOR TORNADO WATCH 502 CONTINUES. SUMMARY...TORNADO WATCH 502 REMAINS IN EFFECT THROUGH 03Z. IT IS POSSIBLE THAT A SEVERE RISK COULD CONTINUE INTO THE OVERNIGHT HOURS... THOUGH UNCERTAINTY IN THIS RISK IS TOO SUBSTANTIAL FOR ADDITIONAL WATCH ISSUANCE AT THIS TIME. DISCUSSION...AN OUTFLOW BOUNDARY/SURFACE TROUGH ANALYZED FROM EAST-CENTRAL MS TO SOUTHWEST MS AND CENTRAL LA MARKS THE NORTHERN EDGE OF GULF-MODIFIED AIR CHARACTERIZED BY LOWER/MIDDLE 60S DEWPOINTS. THE LOW-LEVEL MOISTURE CONTINUES TO SUPPORT MARGINAL BUOYANCY IN THE WARM SECTOR...WHERE WEAKLY ORGANIZED CONVECTIVE CLUSTERS CONTINUE BEING SUPPORTED BY MODEST POSITIVE THETA-E ADVECTION...BEFORE BEING UNDERCUT BY THE SOUTHWARD-ADVANCING BOUNDARY. OCCASIONAL WEAK CIRCULATIONS HAVE BEEN NOTED WITH ACTIVITY IN PROXIMITY TO THE BOUNDARY IN CENTRAL MS. OVERALL...CONVECTION IS PRESENTLY WEAKLY ORGANIZED...AS STRONGER LOW-LEVEL/DEEP ASCENT CONTINUE LIFTING WELL TO THE NORTH OF THE REGION. THE UNDERCUTTING NATURE OF THE BOUNDARY...AND CONVECTIVE-CLUSTER MODE...MAY LIMIT SUSTAINABILITY OF INTENSE CONVECTION. ADDITIONALLY...POOR MID-LEVEL LAPSE RATES ARE LIMITING CONVECTIVE-SCALE UPWARD ACCELERATIONS. NEVERTHELESS...WITH NOTABLY RICHER LOW-LEVEL MOISTURE ALONG THE GULF COAST -- I.E....DEWPOINTS IN THE UPPER 60S TO AROUND 70F -- THE POTENTIAL FOR INCREASING MOISTURE AND WEAK DESTABILIZATION MAY EXIST OVERNIGHT NEAR/SOUTH OF THE FRONTOLYTIC BOUNDARY. WITH MODEST LARGE-SCALE ASCENT PERSISTING OVER THE AREA WITHIN THE RIGHT-ENTRANCE REGION OF A HIGH-LEVEL SPEED MAXIMUM...SOME INCREASE IN CONVECTIVE INTENSITY MAY OCCUR LATER THIS EVENING INTO THE OVERNIGHT HOURS. GIVEN VERY STRONG WIND FIELDS PERSISTING ACROSS THE AREA...A CONDITIONAL SEVERE-THUNDERSTORM/TORNADO RISK COULD PERSIST. IF A PROMINENT CHANGE IN THE CHARACTER OF CONVECTION WERE TO BECOME APPARENT...THE ISSUANCE OF A NEW WATCH COULD BECOME NECESSARY. OTHERWISE...ADDITIONAL WATCH ISSUANCE IS NOT ANTICIPATED. ..COHEN.. 11/29/2016 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BMX...MOB...JAN...LIX... LAT...LON 30409162 31219128 32218870 32038805 31448798 30718864 30269075 30409162 NNNN