ZCZC SPCSWOMCD ALL
ACUS11 KWNS 170538 
SPC MCD 170538 
KYZ000-INZ000-ILZ000-170745-

MESOSCALE DISCUSSION 1043
NWS STORM PREDICTION CENTER NORMAN OK
1238 AM CDT WED JUN 17 2015

AREAS AFFECTED...PORTIONS OF SERN IL...SRN INDIANA...NRN/WRN KY

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 170538Z - 170745Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...THE RISK FOR A FEW STRONG TSTMS CROSSING PARTS OF THE
LOWER OHIO VALLEY REGION WILL EXIST THROUGH THE OVERNIGHT HOURS. AN
ISOLATED MARGINALLY SVR TSTM CANNOT BE RULED OUT...THOUGH WW
ISSUANCE WILL NOT BE NEEDED.

DISCUSSION...AN AREA OF MULTICELL CONVECTIVE CLUSTERS THAT EVOLVED
FROM DIURNALLY ENHANCED CONVECTION HAS PERSISTED ACROSS PARTS OF THE
LOWER OHIO VALLEY...AHEAD OF A LOW-AMPLITUDE MID-LEVEL SHORTWAVE
TROUGH. WEAK TROUGH-PRECEDING WARM ADVECTION WILL LIKELY SUSTAIN
THESE CONVECTIVE CLUSTERS EWD THROUGH THE OVERNIGHT HOURS DESPITE
NOCTURNAL COOLING OF THE MOIST BOUNDARY LAYER...AS GPS DATA INDICATE
A CORRIDOR OF PW FROM 1.75 TO 2.00 INCHES NEAR AND S OF A SFC FRONT
ANALYZED FROM E-CNTRL IA TO SRN OH. THE VWX VWP SAMPLES AROUND 25-30
KT OF MID-LEVEL SWLYS SURMOUNTING SLY/SSELY FLOW IN THE LOWEST 1 KM
AGL...SUPPORTING SUFFICIENT DEEP SHEAR FOR WEAKLY ORGANIZED
CONVECTION...AS RICH LOW-LEVEL MOISTURE /SFC DEWPOINTS IN THE LOWER
70S/ SUPPORTS SUFFICIENT BUOYANCY FOR TSTMS. LOCALIZED
MESO-GAMMA-SCALE CIRCULATIONS EMBEDDED IN PERSISTENT CONVECTIVE
ELEMENTS/LEWP INFLECTIONS MAY BE ASSOCIATED WITH SOME STRONG TSTM
WIND GUSTS. AN ISOLATED DMGG WIND GUST CANNOT BE ENTIRELY RULED
OUT...AIDED BY PRECIPITATION LOADING. HOWEVER...NOCTURNAL
STABILIZATION OF THE BOUNDARY LAYER WILL DAMPEN THE PROPENSITY OF
DOWNDRAFTS TO BE MANIFESTED AT THE SFC AS STRONG WIND
GUSTS...MARKEDLY MARGINALIZING THE RISK FOR SVR TSTMS. ALSO...POOR
LAPSE RATES AND ONLY MODEST DEEP SHEAR WILL GREATLY NEGATE THE
SVR-TSTM RISK.

..COHEN/GOSS.. 06/17/2015

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...LMK...IND...PAH...

LAT...LON   37718853 38218776 38518692 38478615 37768600 37228718
            37278854 37718853 

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