Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 240730
SWOMCD
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



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