[MCD] SWOMCD

Wed Jun 21 11:27:20 UTC 2006

ACUS11 KWNS 211127
SWOMCD
SPC MCD 211127 
INZ000-ILZ000-WIZ000-IAZ000-MOZ000-211330-

MESOSCALE DISCUSSION 1269
NWS STORM PREDICTION CENTER NORMAN OK
0627 AM CDT WED JUN 21 2006

AREAS AFFECTED...ERN IA/SRN WI/NRN IL

CONCERNING...CONVECTIVE TRENDS/HEAVY RAINFALL 

VALID 211127Z - 211330Z

CLUSTER OF THUNDERSTORMS CONTINUES DEVELOPING NWD ACROSS ERN IA/NRN
IL/SRN WI.  STRONGER STORMS WILL REMAIN CAPABLE OF PRODUCING HAIL
AND/OR LOCALLY-GUSTY WINDS...AND LOCALLY HEAVY RAINFALL WILL ALSO
OCCUR. WW NOT ANTICIPATED ACROSS SRN WI...BUT WILL LIKELY BECOME
NECESSARY OVER THE NEXT SEVERAL HOURS ACROSS THE ERN IA/CENTRAL AND
NRN IL/NRN MO REGION WITH TIME.

40 TO 50 KT WSWLY LOW-LEVEL JET CONTINUES ACROSS THE MIDDLE MO
VALLEY AND INTO SRN PORTIONS OF THE UPPER GREAT LAKES...WHICH
CONTINUES TO SUPPORT WIDESPREAD CONVECTION EARLY THIS MORNING. 
THOUGH A VERY SHALLOW...NOCTURNALLY-STABLE BOUNDARY LAYER EXISTS
ACROSS THIS REGION...2000 TO 3000 J/KG MEAN-LAYER CAPE IS INDICATED
FROM NEB EWD INTO NRN IL/FAR SRN WI.  THIS COMBINED WITH
FAVORABLY-STRONG WIND FIELD VEERING WITH HEIGHT TO WLY AT 40 TO 50
KT AT MID-LEVELS HAS SUPPORTED TRANSIENT SEVERE STORMS -- WITH HAIL
AND A FEW STRONG/DAMAGING GUSTS.

AREA OF STORMS HAS SHOWN NWD PROPAGATION WITH TIME ACROSS ERN IA AND
INTO SRN WI DESPITE WLY MEAN FLOW/CELL MOTION -- APPARENTLY DUE TO A
NWD-MOVING OUTFLOW BOUNDARY.  WITH STORMS THUS MOVING AWAY FROM MORE
FAVORABLE REGION OF WARM ADVECTION AND INTO A LESS UNSTABLE
AIRMASS...EXPECT THREAT FOR HAIL/LOCALLY DAMAGING WINDS TO REMAIN
GENERALLY LIMITED.  MEANWHILE...DEGREE OF LOW-LEVEL MOISTURE AND
VIGOROUS/PERSISTENT CONVECTION SUGGESTS THAT LOCALLY-HEAVY RAINFALL
WILL CONTINUE -- PARTICULARLY ACROSS SERN WI OVER THE NEXT 1 TO 2
HOURS.

LATEST WATER VAPOR IMAGERY INDICATES A MID-/UPPER-LEVEL CIRCULATION
CENTER MOVING ACROSS KS/NEB ATTM...WITH A SURFACE REFLECTION OF THIS
CIRCULATION NOW CROSSING THE MO VALLEY INTO SWRN IA ACCORDING TO
RADAR LOOP.  ATTM...GREATEST THREAT FOR MORE SIGNIFICANT SEVERE
WEATHER APPEARS TO EXIST ALONG SRN FRINGE OF ONGOING CONVECTIVE
CLUSTER...AS UPPER CIRCULATION CENTER MOVES EWD AND INTERACTS WITH
POSSIBLE OUTFLOW BOUNDARY ON SRN FRINGE OF THE MCS.  WITH SWRN MOST
CELLS WITHIN CONVECTIVE CLUSTER -- ACROSS SERN IA -- RECENTLY
EXHIBITING A MORE ELY MOVEMENT...WE WILL CONTINUE TO MONITOR THIS
PORTION OF THE MCS FOR SIGNS OF INCREASED ORGANIZATION AND POTENTIAL
ONSET OF A MORE WIDESPREAD SEVERE EVENT WHICH WOULD REQUIRE WW
ISSUANCE.

..GOSS.. 06/21/2006

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

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

43808910 43578793 42038689 40678717 39798948 39699404
40579476 41899356 43349156 

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