ZCZC SPCSWOMCD ALL ACUS11 KWNS 171758 SPC MCD 171758 ALZ000-MSZ000-LAZ000-TXZ000-171930- MESOSCALE DISCUSSION 0227 NWS STORM PREDICTION CENTER NORMAN OK 1258 PM CDT THU MAR 17 2016 AREAS AFFECTED...PARTS OF CNTRL LA...SRN MS AND ADJACENT SRN AL CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 171758Z - 171930Z PROBABILITY OF WATCH ISSUANCE...80 PERCENT SUMMARY...AN INCREASE IN BOUNDARY LAYER BASED STORM DEVELOPMENT APPEARS POSSIBLE WITHIN THE NEXT FEW HOURS NEAR/SOUTH OF THE INTERSTATE 20 CORRIDOR...ACCOMPANIED BY THE RISK FOR SEVERE HAIL/WIND. DISCUSSION...SURFACE CONVERGENCE IS GENERALLY WEAK...AND FORCING FOR CONVECTIVE DEVELOPMENT REMAINS UNCLEAR. HOWEVER...A MOIST BOUNDARY LAYER CONTINUES TO DESTABILIZE /CAPE IN EXCESS OF 1000 J PER KG/ ALONG A FRONTAL ZONE NEAR/SOUTH OF THE INTERSTATE 20 CORRIDOR OF LOUISIANA AND MISSISSIPPI. MID-LEVEL INHIBITION ACROSS THIS REGION APPEARS TO BE WEAKENING WITH INSOLATION...AND SOME INCREASE IN CONVECTIVE DEVELOPMENT IS CURRENTLY UNDERWAY ALONG/NORTH OF THE INTERSTATE 10 CORRIDOR. IT IS POSSIBLE THAT ONGOING ACTIVITY MAY CONTINUE TO SLOWLY INCREASE/INTENSIFY WHILE DEVELOPING EAST NORTHEASTWARD THROUGH THE AFTERNOON HOURS. HOWEVER...THE HIGH RESOLUTION RAPID REFRESH HAS BEEN SUGGESTIVE THAT MORE SUBSTANTIVE THUNDERSTORM DEVELOPMENT IS POSSIBLE ON THE SOUTHERN FLANK OF CONVECTION NOW ROOTED ABOVE COOL SURFACE-BASED AIR ACROSS THE ARKLATEX INTO CENTRAL MISSISSIPPI. THIS WOULD PROBABLY BE SUPPORTED BY WEAK LOW-LEVEL WARM ADVECTION...AND PERHAPS SUBTLE MID-LEVEL HEIGHT FALLS...WITH THE TENDENCY FOR ACTIVITY TO BECOME INCREASINGLY ROOTED WITHIN THE BOUNDARY LAYER. IF/WHEN THIS OCCURS...IT PROBABLY WOULD BE ACCOMPANIED BY A MORE APPRECIABLE RISK FOR SEVERE HAIL AND SURFACE GUSTS...AIDED BY STRONG VERTICAL SHEAR BENEATH 40-50+ KT WESTERLY 500 MB FLOW. ..KERR/HART.. 03/17/2016 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MOB...JAN...LIX...LCH...SHV... LAT...LON 32129355 32219163 32369025 32028890 31778823 31138844 30839110 30459312 31369381 32129355 NNNN