ZCZC SPCSWOMCD ALL ACUS11 KWNS 301811 SPC MCD 301811 GAZ000-FLZ000-ALZ000-302045- MESOSCALE DISCUSSION 0159 NWS STORM PREDICTION CENTER NORMAN OK 0111 PM CDT MON MAR 30 2015 AREAS AFFECTED...FAR SRN AL...FAR SRN GA...THE FL PANHANDLE CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 301811Z - 302045Z PROBABILITY OF WATCH ISSUANCE...5 PERCENT SUMMARY...THE RISK FOR ISOLATED STRONG THUNDERSTORMS IS INCREASING THIS AFTERNOON...THOUGH WW ISSUANCE WILL NOT BE NEEDED. DISCUSSION...LOW-LEVEL LAPSE RATES ARE STEEPENING S OF A FRONTAL ZONE AND ACCOMPANYING MULTI-LAYERED CLOUDS THAT VIS IMAGERY/SFC OBSERVATIONS HIGHLIGHT FROM CNTRL MS TO PORTIONS OF CNTRL/SRN AL/GA. DIFFERENTIAL-HEATING-INDUCED BAROCLINICITY ON THE FRINGES OF THESE CLOUDS COUPLED WITH MODEST BACKGROUND FRONTAL ASCENT ARE LEADING TO RECENT AGITATION IN CU FIELDS INVOF FAR SRN AL/FAR SWRN GA. ISOLATED DEEPER CONVECTION SHOULD BLOSSOM FROM THIS ACTIVITY DURING THE NEXT FEW HOURS OWING TO CONTINUED DIURNAL HEATING COUPLED WITH THE GRAZING INFLUENCE OF MIDLEVEL ASCENT AT THE SRN END OF AN ERN-CONUS MIGRATORY TROUGH PER WATER VAPOR LOOPS. MODIFICATIONS TO RAP FORECAST SOUNDINGS TO ACCOUNT FOR CURRENT SFC OBSERVATIONS INDICATE 500-1250 J/KG OF MLCAPE -- ENHANCED BY 7-8-C/KM LAPSE RATES IN THE H7-H5 LAYER AS SAMPLED BY UPSTREAM 12Z JAN/LIX RAOBS. WITH MODERATE WLY/WNWLY FLOW THROUGH THE CONVECTIVE-CLOUD LAYER EVIDENT IN VAX/TLH VWPS...RELATIVELY LONG/STRAIGHT HODOGRAPHS MAY FAVOR SPLITTING...MARGINAL SUPERCELL STORMS WITH STRONG WIND GUSTS AND HAIL -- PERHAPS REACHING SVR LEVELS ON AN ISOLATED BASIS. HOWEVER...WITH ONLY MODEST LOW-LEVEL FLOW AND RELATED WEAK LOW-LEVEL CONVERGENCE...AND GIVEN ONLY MODEST TROPOSPHERIC MOISTURE /PW AROUND 0.75-1.00 INCH PER GPS IMAGERY/...THE OVERALL COVERAGE OF ROBUST UPDRAFTS WITH SVR-TSTM POTENTIAL WILL LIKELY REMAIN LIMITED. ..COHEN/HART.. 03/30/2015 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...JAX...TAE...MOB... LAT...LON 30808309 30308288 30088413 30428644 30828764 31218796 31368740 30808309 NNNN