[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 211128
SWOMCD
SPC MCD 211127 
ILZ000-WIZ000-IAZ000-211330-

MESOSCALE DISCUSSION 1808
NWS STORM PREDICTION CENTER NORMAN OK
0627 AM CDT THU JUL 21 2005

AREAS AFFECTED...ERN/SERN IA...CENTRAL/NRN IL...AND SRN WI

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 211127Z - 211330Z

LEADING EDGE OF LARGE-SCALE...NOCTURNAL MCS EXTENDING AT 11Z FROM
30S MSP TO CID TO IRK WILL CONTINUE GENERALLY EWD AT 40-45KT THROUGH
 ERN/SERN IA INTO IL. EXTRAPOLATION TAKES SYSTEM INTO CHICAGO AND
MILWAUKEE METRO AREAS BETWEEN 15-16Z. AN ADDITIONAL WW MAY BE
REQUIRED DURING THE NEXT 1-2 HOURS FOR THREAT OF DAMAGING WINDS AND
ISOLATED LARGE HAIL.

CURRENT SURFACE ANALYSIS INDICATES THAT A QUASI-STATIONARY FRONT
EXTENDS EWD FROM ONGOING MCS OVER IA/MN/NRN MO ALONG THE WI/IL
BORDER AND ACROSS FAR SRN LOWER MI. MOISTURE POOLING WITH SURFACE
DEWPOINTS IN THE LOW 70S ALONG BOUNDARY IS CONTRIBUTING TO AN E-W
INSTABILITY AXIS WITH 100MB MLCAPE VALUES OF 2000-3000 J/KG
CURRENTLY. ALOFT...700-500MB FLOW BENDS SEWD ACROSS WI/IL ON NERN
PERIPHERY OF LARGE UPPER RIDGE CENTERED OVER THE FOUR CORNERS
STATES. THIS SUGGESTS ONGOING MCS MAY GRADUALLY TURN SEWD THROUGH
MID-MORNING. GIVEN ONLY WEAK TO MODERATE CINH...ISOLATED DAMAGING
WINDS/HAIL CURRENTLY MAY BECOME MORE WIDESPREAD WITH ONSET OF
SURFACE HEATING OVER THE NEXT FEW HOURS. SFC MESO HIGH...MODERATE
WNWLY DEEP-LAYER SHEAR...AND UPPER DIFFLUENT FLOW SHOULD ALSO
CONTRIBUTE TO MCS MAINTENENCE. AN ADDITIONAL WW MAY BE NEEDED TO
COVER EWD/SEWD PROGRESSION OF MCS INTO SRN WI AND NRN/CENTRAL IL
THROUGH THE LATE MORNING HOURS.

..BANACOS.. 07/21/2005

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

ATTN...WFO...LOT...ILX...MKX...LSX...DVN...ARX...

41389172 42369176 42649139 42738933 42728789 41788767
40468771 39758790 39528836 39598934 39819037 40099095
40399145 

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