ZCZC SPCSWOMCD ALL ACUS11 KWNS 231019 SPC MCD 231019 MSZ000-LAZ000-231215- MESOSCALE DISCUSSION 1982 NWS STORM PREDICTION CENTER NORMAN OK 0419 AM CST TUE DEC 23 2014 AREAS AFFECTED...PORTIONS OF SOUTHEAST MISSISSIPPI AND SOUTHEAST LOUISIANA CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 231019Z - 231215Z PROBABILITY OF WATCH ISSUANCE...5 PERCENT SUMMARY...SOME STRONG-THUNDERSTORM RISK WILL EXIST DURING THE PRE-DAWN HOURS. IN THE SHORT-TERM...WW ISSUANCE WILL NOT BE NECESSARY. DISCUSSION...SFC ANALYSES INDICATE MOIST...MARINE-MODIFIED AIR CONTINUING TO ADVANCE NWD...WITH MIDDLE-60S DEWPOINTS SPREADING NWD ACROSS SERN LA/SERN MS. RICHER...MORE STRONGLY MODIFIED GULF MOISTURE -- E.G. SFC DEWPOINTS IN THE LOWER 70S -- RESIDES S OF A WARM FRONT ANALYZED JUST OFFSHORE FROM SERN LA. THE EARLIER 00Z LIX RAOB AND MODIFICATIONS TO THIS SOUNDING SUGGEST THAT SUFFICIENTLY HIGH THETA-E EXISTS IN THE BOUNDARY LAYER FOR 500-1000 J/KG OF MLCAPE WITH SFC-BASED EFFECTIVE INFLOW LAYERS...ESPECIALLY WITHIN ABOUT 100 MILES OF THE COAST. AREA RADARS AND LIGHTNING DATA INDICATE A RECENT UPTICK IN CONVECTION W AND N OF LAKE PONTCHARTRAIN. THIS ACTIVITY IS LIKELY ASSOCIATED WITH A NARROW FILAMENT OF MID-LEVEL ASCENT PROGRESSING NEWD ON THE SERN PERIPHERY OF BROADER CYCLONIC FLOW OVER THE CNTRL CONUS...PER MOISTURE-CHANNEL IMAGERY. UNTIL LARGER-SCALE ASCENT INCREASES LATER IN THE MORNING...ONLY A GRADUAL INCREASE IN CONVECTIVE COVERAGE AND INTENSITY IS EXPECTED DURING THE NEXT FEW HOURS UNDER THE INFLUENCE OF THE AFOREMENTIONED ASCENT FILAMENT. LIX AND JAN VWPS SAMPLE OVER 50 KT OF MID-LEVEL SWLYS THAT WILL OFFER SUFFICIENT DEEP SHEAR FOR SUSTAINED/ORGANIZED CONVECTION. LOW-LEVEL FLOW IS PRESENTLY MODEST...THOUGH SUFFICIENT DIRECTIONAL SHEAR EXISTS FOR THE POSSIBILITY OF GENERALLY WEAK STORM-SCALE CIRCULATIONS AND PERHAPS A BRIEF/WEAK TORNADO. CONVECTION EVOLVING ACROSS MARION AND JEFFERSON DAVIS COUNTIES IN SERN MS HAS ALREADY EXHIBITED WEAK/ELONGATED CYCLONIC SHEAR ZONES. SIMILAR TRENDS WILL LIKELY BE NOTED WITH CONVECTION ACROSS THE REGION BEFORE DAWN. HOWEVER...NOTHING MORE THAN A BRIEF/WEAK TORNADO OR PERHAPS A STRONG WIND GUST ARE EXPECTED WHILE LOW-LEVEL FLOW REMAINS WEAK AND LARGE-SCALE ASCENT MODEST. ..COHEN/EDWARDS.. 12/23/2014 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MOB...JAN...LIX...LCH... LAT...LON 29239240 29739290 30469199 31878985 31808866 30028855 28908935 29239240 NNNN