[MCD] SWOMCD

Mon Sep 4 16:58:12 UTC 2006

ACUS11 KWNS 041659
SWOMCD
SPC MCD 041659 
ILZ000-WIZ000-041830-

MESOSCALE DISCUSSION 1930
NWS STORM PREDICTION CENTER NORMAN OK
1159 AM CDT MON SEP 04 2006

AREAS AFFECTED...EXTREME SWRN/SCNTRL WI AND NRN/CNTRL IL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 041659Z - 041830Z

16Z SFC ANALYSIS/HIGH-RESOLUTION RADAR IMAGERY SHOWED A CONVERGENCE
ZONE ARCING FROM CNTRL IA THROUGH SWRN WI...THEN SWD ACROSS NWRN IL.
 AHEAD OF THIS FEATURE...SATL SUGGESTED THAT BREAKS IN THE OVERCAST
EXIST AND SUFFICIENT INSOLATION WAS OCCURRING TO SUPPORT CONVECTIVE
INITIATION.  TEMPERATURES SHOULD CONTINUE TO WARM 2-4 MORE DEGREES F
AND TSTMS WILL BECOME MORE NUMEROUS THIS AFTN.

H5 TEMPERATURES OF MINUS 16-18 DEG C ATOP RESIDUAL BOUNDARY LAYER
MOISTURE AND THE MODEST LOW-LEVEL HEATING WILL CONTRIBUTE TO SBCAPES
OF 1000-1500 J/KG.  THE STEEP LAPSE RATES WILL BE CONDUCIVE FOR
ISOLD STRONGER STORMS TO PRODUCE LARGE HAIL AND GUSTY WINDS.  A
BRIEF ISOLD TORNADO IS ALSO POSSIBLE...MAINLY ACROSS EXTREME NRN IL
AND SRN WI WHERE LOW-LEVEL WINDS WERE BACKED TO A MORE ELY DIRECTION
ALONG/N OF THE ARCING CONVERGENCE ZONE.

THE SEVERITY OF THE STORMS ACROSS EXTREME NRN IL AND SRN WI MAY BE
TEMPERED SOMEWHAT BY THE NUMBER AND SPACING OF THE STORMS THAT
INITIATE.  HERE...UPDRAFTS MAY BE SHORTER LIVED AND WEAKER AS
UPDRAFT-DOWNDRAFT INTERFACES ARE CLOSELY SPACED.  TSTMS THAT DEVELOP
FARTHER S IN NRN/CNTRL IL WILL BE POTENTIALLY MORE DISCRETE
AND...THUS...LONGER-LIVED AND STRONGER.

..RACY.. 09/04/2006

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

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

40509070 41808974 42319023 42629063 42999051 43118981
42928916 42148804 41048826 40178937 40199028 

WWWW