ZCZC SPCSWOMCD ALL ACUS11 KWNS 231815 SPC MCD 231815 FLZ000-232015- MESOSCALE DISCUSSION 0302 NWS STORM PREDICTION CENTER NORMAN OK 0115 PM CDT SAT MAR 23 2013 AREAS AFFECTED...CNTRL/NRN FL PENINSULA CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 231815Z - 232015Z PROBABILITY OF WATCH ISSUANCE...20 PERCENT SUMMARY...A FEW STRONG TO ISOLATED SVR STORMS COULD DEVELOP AFTER 1900Z. GIVEN THE ANTICIPATED ISOLATED COVERAGE OF ANY SVR THREAT...THE ISSUANCE OF A WW IS UNLIKELY. DISCUSSION...DEEPENING BOUNDARY LAYER CIRCULATIONS WITHIN THE WARM SECTOR S OF A NRN-FL WARM FRONT HAVE BEEN SUPPORTING HORIZONTAL CONVECTIVE ROLLS/CLOUD STREETS ORIENTED PARALLEL TO LOW-LEVEL SWLY FLOW EARLY THIS AFTERNOON. AREA RADAR DATA SUGGEST THAT RELATIVELY DEEPER CONVECTIVE PLUMES HAVE OCCASIONALLY EVOLVED ALONG THE ASCENDING BRANCHES OF THESE ROLLS. MODIFIED 12Z TBW RAOB DATA TO ACCOUNT FOR SFC TEMPS IN THE LOWER 80S AND DEWPOINTS IN THE UPPER 60S AND LOWER 70S ARE SUPPORTING 1500-2500 J/KG OF MLCAPE. A FEW MORE VIGOROUS UPDRAFTS MAY EVOLVE THIS AFTERNOON OWING TO CONTINUED DIABATIC SFC HEATING...AND AS LOW-LEVEL ASCENT IS LOCALLY AUGMENTED INVOF A MODESTLY STRENGTHENING SEA BREEZE CIRCULATION ALONG THE NATURE COAST. ALSO...A SUPERCELL STORM OVER THE NE GULF WILL CONTINUE TO BE MONITORED. WHILE ITS EVENTUAL IMPACTS TO THE FL BIG BEND ARE UNCERTAIN...IT MAY POSE A SVR THREAT TO PARTS OF LEVY COUNTY IN A FEW HOURS. STRONGER STORMS THAT DEVELOP WILL BE CONDITIONALLY CAPABLE OF PRODUCING SVR HAIL AND DMGG WIND GUSTS...AS STEEP MID-LEVEL LAPSE RATES ACCOMPANYING AN EML COMBINE WITH 40-55 KT OF EFFECTIVE BULK SHEAR TO SUPPORT VIGOROUS UPDRAFTS. HOWEVER...THE GREATER SVR THREAT WILL BE CONFINED TO AREAS N OF THE MCD AREA -- NEAR AND N OF THE WARM FRONT -- WHERE STRONGER/DEEPER ASCENT AND RELATIVELY COOLER MID-LEVEL TEMPERATURES WILL PROMOTE GREATER COVERAGE OF PERSISTENT CONVECTION. AS SUCH...ANY SVR THREAT WILL LIKELY BE ISOLATED ACROSS CNTRL/NRN PARTS OF THE FL PENINSULA. ..COHEN/HART.. 03/23/2013 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MLB...TBW...JAX... LAT...LON 29718259 29678180 29398117 28498074 27918061 27508098 27378147 27528210 27908258 28898267 29378292 29718259 NNNN