[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 271912
SWOMCD
SPC MCD 271911 
PAZ000-WVZ000-OHZ000-KYZ000-INZ000-272115-

MESOSCALE DISCUSSION 1901
NWS STORM PREDICTION CENTER NORMAN OK
0211 PM CDT SUN AUG 27 2006

AREAS AFFECTED...PORTIONS SWRN PA...SERN INDIANA...CENTRAL/SRN
OH...CENTRAL THROUGH NERN KY...NRN THROUGH WRN WV.

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 271911Z - 272115Z

STG-SVR GUSTS AND HAIL ARE POSSIBLE WITH TSTMS EXPECTED TO CONTINUE
MOVING SEWD ACROSS OH VALLEY REGION BETWEEN SDF-PIT...EVENTUALLY
INTO HIGHER TERRAIN OF WV AND NERN KY. SCATTERED TO WIDELY
SCATTERED TSTMS GRADUALLY ARE INCREASING IN STRENGTH ACROSS THIS
REGION AS INFLOW-LAYER AIR MASS BECOMES MORE HEATED/UNSTABLE. 
VERTICAL SHEAR PROFILES APPEAR MRGL FOR SUPERCELLS...THOUGH SOME
ROTATION AND RELATED ENHANCEMENT TO HAIL POTENTIAL MAY DEVELOP. 
WEAK DEEP-LAYER LAPSE RATES AND LACK OF MORE ROBUST LOW LEVEL SHEAR
SHOULD LIMIT POTENTIAL TO GENERATE VERY LARGE HAIL.  PRIMARY MODE OF
CONVECTION WILL BE MULTICELLULAR...WITH DAMAGING GUSTS BEING MAIN
CONCERN.

SFC ANALYSIS SHOWS COLD FRONT MOVING SEWD ACROSS NWRN OH AND CENTRAL
INDIANA...PREFRONTAL CONVERGENCE LINE FROM E-CENTRAL OH SWWD THROUGH
CVG/EVV AREAS...AND DIFFUSE WARM FRONT MOVING SLOWLY NEWD OVER
EXTREME ERN OH...EXTREME SWRN PA AND NRN MD.  S OF WARM FRONT AND
CONVERGENCE BAND...MODIFIED RAOBS AND RUC SOUNDINGS INDICATE SFC DEW
POINTS UPPER 60S-MID 70S F AND SFC HEATING WILL OFFSET NEARLY MOIST
ADIABATIC MID-UPPER LEVEL LAPSE RATES ENOUGH TO YIELD 1000-1500 J/KG
MLCAPES INVOF OH RIVER...WITH SLIGHT INCREASING TREND SWWD.  BY
CONTRAST...DEEP-LAYER SHEAR WILL DIMINISH SWWD WITH DISTANCE FROM
GRADIENT ENHANCEMENTS ALOFT...ASSOCIATED WITH SERN CANADA SHORTWAVE
TROUGH.  DIRECTIONAL SHEAR ALSO IS LIMITED BY WLY COMPONENT OF SFC
FLOW...THOUGH ENOUGH LOW LEVEL SPEED SHEAR IS PRESENT FOR AROUND 150
J/KG 0-3 KM SRH...FOR ANY CELLS SHOWING SUBSTANTIAL SEWD/RIGHTWARD
DEVIANCE.

..EDWARDS.. 08/27/2006

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

ATTN...WFO...PBZ...RLX...CLE...JKL...ILN...LMK...IND...

37098583 39358590 41078005 38917990 

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