[MCD] SWOMCD

Wed Jul 19 16:42:58 UTC 2006

ACUS11 KWNS 191640
SWOMCD
SPC MCD 191640 
WIZ000-ILZ000-IAZ000-MNZ000-191815-

MESOSCALE DISCUSSION 1560
NWS STORM PREDICTION CENTER NORMAN OK
1140 AM CDT WED JUL 19 2006

AREAS AFFECTED...FAR SERN MN / W-CNTRL AND SWRN WI/ NERN IA / NWRN
IL

CONCERNING...SEVERE THUNDERSTORM WATCH 616...

VALID 191640Z - 191815Z

THE POTENTIAL FOR DAMAGING WINDS AND LARGE HAIL IS FORECAST TO
CONTINUE THROUGH THE AFTERNOON IN ASSOCIATION WITH ONGOING MCS. 
ADDITIONAL WW/S MAY BECOME NECESSARY WITH TIME.

A COMPLEX MCS EVOLUTION HAS OCCURRED THIS MORNING AS LARGER-SCALE
BOW ECHO OVER SERN MN HAS GRADUALLY WEAKENED WHILE SMALLER BOW OVER
NERN IA HAS MAINTAINED ITS INTENSITY.  AT 0.5 DEGREES...STRONG
INBOUND RADIAL VELOCITIES HAVE PERSISTED ON LACROSSE WI RADAR IN
ASSOCIATION WITH THE NRN BOW ECHO...HOWEVER ONLY FEW REPORTS OF
DAMAGING WINDS OR WIND DAMAGE HAVE BEEN RECEIVED.  BASED ON RUC
PROXIMITY SOUNDINGS...IT APPEARS THAT  SYSTEM MAY STILL BE SLIGHTLY
ELEVATED...PREVENTING THE MOST INTENSE DOWNDRAFTS FROM REACHING THE
GROUND.

MESOANALYSIS AND RUC OBJECTIVE FIELDS INDICATE THAT RAPID AIR MASS 
DESTABILIZATION IS OCCURRING ACROSS DOWNSTREAM AIR MASS ACROSS SRN
AND CNTRL WI...TO THE S OF A SECONDARY WARM FRONT/MOISTURE
DISCONTINUITY ANALYZED FROM INTERSECTION WITH MCS N OF LSE EWD TO S
OF OSH.  THEREFORE...POTENTIAL WILL EXIST FOR RE-INTENSIFICATION OF
DECAYING NRN BOW ECHO AS LEADING EDGE OF GUST FRONT BEGINS TO
ENCOUNTER THIS MORE UNSTABLE AIR.  

FARTHER S OVER NERN IA...STRONG CONVECTION CONTINUES TO DEVELOP
PROGRESSIVELY FARTHER S TO VICINITY OF MAIN SYNOPTIC WARM FRONT
STRETCHING FROM APPROXIMATELY 20 ESE FOD TO 30 W MLI.  WHILE
MID-LEVEL WIND FIELDS TEND TO DIMINISH WITH SRN EXTENT...INSTABILITY
INCREASES OWING TO VERY MOIST BOUNDARY-LAYER CONDITIONS. 
THEREFORE...EXPECTED THE THREAT OF SEVERE STORMS CAPABLE OF DAMAGING
WINDS AND LARGE HAIL TO GRADUALLY DEVELOP S OF WW 616 INTO E-CNTRL
IA AND NWRN IL THIS AFTERNOON.

..MEAD.. 07/19/2006

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

ATTN...WFO...GRB...MKX...DVN...ARX...DMX...

42229240 43019249 43859216 44249148 44429064 44308976
43028946 42088979 41639053 41629137 