ZCZC SPCSWOMCD ALL ACUS11 KWNS 240730 SPC MCD 240730 FLZ000-241000- MESOSCALE DISCUSSION 0040 NWS STORM PREDICTION CENTER NORMAN OK 0130 AM CST SAT JAN 24 2015 AREAS AFFECTED...COASTAL AREAS OF WEST-CENTRAL TO SOUTHWEST FL CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 240730Z - 241000Z PROBABILITY OF WATCH ISSUANCE...20 PERCENT SUMMARY...A MARGINAL THREAT FOR A BRIEF TORNADO EXISTS DURING THE OVERNIGHT TO EARLY THIS MORNING ALONG THE WEST-CENTRAL /NEAR VENICE/ TO SOUTHWEST FL GULF COAST /IN VICINITY OF NAPLES/ WITH ANY WATERSPOUTS THAT REACH THE COAST. GIVEN THE LOW THREAT AND LIMITED SPATIAL EXTENT...A TORNADO WATCH ISSUANCE IS NOT WARRANTED. DISCUSSION...AT 07Z...MOSAIC RADAR IMAGERY SHOWED A PRE-FRONTAL QLCS EXTENDING SWWD FROM SARASOTA COUNTY THROUGH THE SERN GULF OF MEXICO TO APPROXIMATELY 125 NM WNW EYW. THE ENVIRONMENT EAST OF THIS CONVECTION TO COASTAL AREAS OF WEST-CENTRAL TO SOUTHWEST FL IS MARGINALLY UNSTABLE /MUCAPE 500-900 J PER KG/ WITH SURFACE DEWPOINTS AT OBSERVATION SITES ALONG THE COAST NEAR 70 F. DESPITE THE MARGINAL INSTABILITY...EFFECTIVE BULK SHEAR OF 40-50 KT IS SUFFICIENTLY STRONG TO SUPPORT SUSTAINED ROTATION AS HAS BEEN OBSERVED WITH AT LEAST ONE STORM CURRENTLY MOVING ONTO THE COAST OF SARASOTA COUNTY /NEAR 15-20 SM SSE SRQ/. VWP DATA PER TPA/EYW WSR-88D/S AND OBJECTIVE MESOANALYSIS /EFFECTIVE SRH OF 200-300 M2 PER S2/ INDICATED LOW-LEVEL SHEAR /GIVEN SLY PRE-FRONTAL WINDS/ SUPPORTIVE OF LOW-LEVEL ROTATION. THIS IS CONFIRMED BY A PERSISTENT LOW-LEVEL ROTATIONAL TRACK WITH THE SARASOTA COUNTY STORM PER WDSS-II DATA. THE ONGOING...AFOREMENTIONED...LINE OF STORMS SHOULD REACH THE FORT MYERS AREA AROUND 09-10Z AND THEN INTO NAPLES AROUND 11Z. THE FAVORABLE ENVIRONMENT FOR SPORADIC SUPERCELL STORMS TO POSSIBLY PRODUCE WATERSPOUTS FROM OFFSHORE TO NEAR THE COAST SUGGESTS A BRIEF TORNADO CANNOT BE RULED OUT ALONG THE COAST INTO EARLY SATURDAY MORNING AS THE TSTM ACTIVITY ADVANCES EWD. A MORE STABLE ENVIRONMENT FARTHER INLAND SHOULD LIMIT ANY SEVERE WEATHER THREAT FROM AFFECTING LOCATIONS AWAY FROM THE COASTAL AREA. ..PETERS/EDWARDS.. 01/24/2015 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MFL...TBW... LAT...LON 27158263 27228242 26898221 26618203 26458178 26158170 26058183 26298202 26478221 26748239 27158263 NNNN