[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 251842
SWOMCD
SPC MCD 251842 
INZ000-ILZ000-WIZ000-IAZ000-252045-

MESOSCALE DISCUSSION 1883
NWS STORM PREDICTION CENTER NORMAN OK
0142 PM CDT FRI AUG 25 2006

AREAS AFFECTED...EXTREME E-CENTRAL IA...EXTREME SRN WI...NRN
IL...SRN LM.

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 251842Z - 252045Z

SVR TSTM POTENTIAL MAY BE INCREASING W OF SRN PORTION OF LM...TO
EXTREME ERN IA.  TSTMS SHOULD CONTINUE TO FORM IN WEAKLY CAPPED AND
FAVORABLY UNSTABLE AIR MASS WITH OCCASIONAL HAIL AND STG-SVR GUSTS
POSSIBLE.

SFC ANALYSIS SHOWS LOW OVER SERN CORNER MN...COLD FRONT SSWWD ACROSS
NERN/S-CENTRAL IA.  WARM FRONT EXTENDING E OF LOW BECOMES OBSCURED
WITH EWD EXTENT INTO OUTFLOW POOL LEFT BY EARLIER ACTIVITY ACROSS
SRN WI.  ASSOCIATED OUTFLOW BOUNDARY IS ANALYZED FROM LAKE COUNTY IL
WNWWD ACROSS IOWA COUNTY WI.  ON 18Z SFC MAP...PREFRONTAL CONFLUENCE
LINE IS ANALYZED FROM 20 NW BRL NEWD ACROSS CLINTON COUNTY IA TO
GREEN COUNTY WI.  W OF THAT LINE...SWLY SFC WINDS REDUCE BOTH
CONVERGENCE AND VERTICAL SHEAR ALONG/AHEAD OF FRONT.  NARROW ZONE OF
ENHANCED SFC HEATING HAS PERSISTED IN RELATIVELY CLOUD FREE AREA
FROM ERN IA EWD ACROSS FAR NRN IL...WHERE MLCAPES SHOULD EXCEED 1000
J/KG BY 21Z.  SVR POTENTIAL BECOMES MORE MRGL/CONDITIONAL FARTHER
E...TOWARD ALM...WHERE BUOYANCY WEAKENS.  MOST FAVORABLE AREA
THEREFORE IS BETWEEN OUTFLOW BOUNDARY...CONFLUENCE LINE...ALM...AND
A DIFFERENTIAL HEATING LINE ANALYZED INVOF SRN EDGE OF
WHITESIDE/LEE/DEKALB COUNTIES. ALTHOUGH CONVECTION IS DEVELOPING
AND BECOMING MORE DENSE ON BOTH SIDES OF OUTFLOW
BOUNDARY...PROBABILITIES FOR SUSTAINED AND PERHAPS SVR ACTIVITY ARE
GREATEST ACROSS NRN IL AND SRN WI BORDER COUNTIES.  VERTICAL SHEAR
PROFILES ARE MRGL LARGELY BECAUSE OF WEAK WINDS AROUND 700 MB.

..EDWARDS.. 08/25/2006

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

ATTN...WFO...LOT...MKX...DVN...

43158880 42948786 42748760 41658742 41248759 40918843
41268952 41679085 

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