[MCD] SWOMCD

Wed Aug 23 18:16:55 UTC 2006

ACUS11 KWNS 231817
SWOMCD
SPC MCD 231817 
WIZ000-ILZ000-IAZ000-MNZ000-231945-

MESOSCALE DISCUSSION 1857
NWS STORM PREDICTION CENTER NORMAN OK
0117 PM CDT WED AUG 23 2006

AREAS AFFECTED...SERN MN/PARTS OF CENTRAL-SRN WI/FAR NERN IA/FAR NRN
IL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 231817Z - 231945Z

WW MAY BE REQUIRED FOR SERN MN/FAR NERN IA INTO PARTS OF CENTRAL/SRN
WI AND POSSIBLY FAR NRN IL.

EARLY AFTERNOON SURFACE ANALYSIS SHOWED A SURFACE LOW ALONG THE
CENTRAL PARTS OF THE SD/ND BORDER WITH A WARM FRONT EXTENDING EWD
INTO CENTRAL MN...THEN SEWD TOWARD LSE TO SERN WI INTO CENTRAL LOWER
MI.  STRONG SURFACE HEATING ALONG/S OF THIS BOUNDARY WITHIN MOIST
ENVIRONMENT /SURFACE DEWPOINTS MID-UPPER 60S/ AND STEEP LAPSE RATES
ARE RESULTING IN A MODERATELY-VERY UNSTABLE AIR MASS /MLCAPE UP TO
2500 J/KG/.  WAA ALONG NOSE OF 25 KT SWLY LLJ HAS MAINTAINED
ELEVATED CLUSTER OF STORMS ACROSS CENTRAL WI TO THE N/E OF WARM
FRONT. ADDITIONAL SURFACE HEATING WILL FURTHER WEAKEN SURFACE BASED
INHIBITION THIS AFTERNOON...SUGGESTING GREATER LIKELIHOOD FOR STORMS
TO BECOME SURFACE BASED.  VISIBLE IMAGERY INDICATED NEW CU
DEVELOPING ALONG THE WARM FRONT IN SERN MN/NERN IA AND ADJACENT
PARTS OF WI...WHICH MAY BE INDICATIVE OF WEAKENING CINH.  ONCE
STORMS BECOME SURFACE BASED...INSTABILITY AND 40-50 KT OF EFFECTIVE
SHEAR WILL SUPPORT SUPERCELLS WITH AN ATTENDANT THREAT FOR LARGE
HAIL...DAMAGING WINDS AND TORNADO POTENTIAL.

..PETERS.. 08/23/2006

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

ATTN...WFO...GRB...LOT...MKX...DVN...ARX...MPX...

42579050 43139166 43899255 44429263 44849194 44969101
44859037 44108921 43238848 42338847 42338988 

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