[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 041045
SWOMCD
SPC MCD 041044 
OHZ000-INZ000-041245-

MESOSCALE DISCUSSION 1878
NWS STORM PREDICTION CENTER NORMAN OK
0544 AM CDT WED AUG 04 2004

AREAS AFFECTED...PORTIONS CENTRAL/NERN INDIANA...W-CENTRAL/NWRN OH

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 041044Z - 041245Z

LINE OF TSTMS OVER CENTRAL PORTION OF IL/INDIANA BORDER -- AS OF 10Z
-- SHOULD MOVE GENERALLY EWD 25-30 KT ACROSS CENTRAL INDIANA TOWARD
W-CENTRAL OH OVER NEXT FEW HOURS...WITH SOME POTENTIAL FOR DAMAGING
GUSTS. AREA IS BEING MONITORED FOR POSSIBLE WW.  STRONG GUSTS ALSO
MAY OCCUR SPORADICALLY WITH CONVECTION FARTHER NE -- MOVING FROM
NERN INDIANA ACROSS NWRN OH -- HOWEVER SEVERE PROBABILITIES ARE
LOWER BECAUSE OF WEAKER AVAILABLE INSTABILITY.

SFC MESOANALYSIS SHOWS PRONOUNCED OUTFLOW BOUNDARY FROM WRN LE SWWD
ACROSS WRN OH...TO NEAR A LINE FROM MFD...DAY...IND...40 NNE HUF.
OUTFLOW BOUNDARY STILL IS MOVING EWD ACROSS NRN OH BTU SHOULD
DECELERATE AND BECOME QUASISTATIONARY S OF MFD...WITH PARENT
CONVECTION WELL REMOVED TO NE. BOUNDARY IS BECOMING NEARLY
STATIONARY WWD ACROSS INDIANA AND WILL SERVE AS PRIMARY CONVERGENCE
FOCUS...SFC AND ALOFT -- FOR NEXT CLUSTER OF CONVECTION.  AIR MASS
APPEARS TO BE DESTABILIZING JUST N OF BOUNDARY AS COLD POOL WEAKENS.
 ALTHOUGH OUTFLOW POOL SHOULD HAVE SHALLOW SLOPE ANGLE...PROBABILITY
OF DAMAGING WIND EVENT PENETRATING THROUGH ASSOCIATED STATIC
STABILITY LAYER DECREASES WITH NWD EXTENT AWAY FROM RICHEST LOW
LEVEL MOISTURE.  THIS INDICATES THAT ACTIVITY NOW OVER NERN INDIANA
-- APCHG FWA AREA AS OF 1015Z -- HAS LOWER SEVERE PROBABILITY THAN
CLUSTER W-NW OF IND.  ACTIVITY MAY CONTINUE TO BACKBUILD SWD OVER
WRN/CENTRAL INDIANA...GIVEN PRONOUNCED INCREASE IN BUOYANCY WITH SWD
AND SWWD EXTENT.  ELEVATED MUCAPE RANGES FROM AROUND 1000 J/KG OVER
WRN OH TO BETWEEN 2000-2500 J/KG NEAR HUF...BASED ON RUC SOUNDINGS.
SIGNIFICANT WLY COMPONENT TO LOW LEVEL FLOW WILL LIMIT
STORM-RELATIVE INFLOW EXCEPT NEAR SRN END OF CONVECTIVE CLUSTER AS
WELL...SUGGESTING CORRIDOR ALONG OUTFLOW BOUNDARY IS MOST FAVORED.

..EDWARDS.. 08/04/2004

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

ATTN...WFO...CLE...ILN...IWX...IND...LOT...

39388729 39878744 40278745 40618720 40658627 40728575
41048557 41158529 41158392 41058323 40838266 40668267
40188313 39748370 39628441 39348556