[MCD] SWOMCD

Wed Apr 12 02:51:09 UTC 2006

ACUS11 KWNS 120249
SWOMCD
SPC MCD 120249 
ILZ000-IAZ000-WIZ000-MOZ000-KSZ000-120415-

MESOSCALE DISCUSSION 0484
NWS STORM PREDICTION CENTER NORMAN OK
0949 PM CDT TUE APR 11 2006

AREAS AFFECTED...ERN IA...PARTS OF NRN MO...SW WI...NW IL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 120249Z - 120415Z

SEVERE POTENTIAL IS EXPECTED TO DIMINISH NEXT FEW HOURS.

FORCING IN EXIT REGION OF CYCLONIC MID-LEVEL JET STREAK...FOCUSED
ALONG/AHEAD OF WEAKENING SURFACE LOW/COLD FRONT...HAS PROGRESSED
THROUGH NARROW TONGUE OF STRONGER SURFACE BASED INSTABILITY...WHERE
LAPSE RATES BECAME QUITE STEEP THIS AFTERNOON WITH DAYTIME HEATING. 
THOUGH RUC GUIDANCE SUGGESTS UPPER SPEED MAXIMUM IS WEAKENING...MID-
LEVEL COOLING/LIFT MAY MAINTAIN SUFFICIENT DESTABILIZATION FOR
CONTINUATION OF THUNDERSTORM ACTIVITY EASTWARD ACROSS THE REMAINDER
OF IOWA/NORTHERN MISSOURI BY 06Z.  RELATIVE HUMIDITIES BELOW CLOUD
BASES LIKELY WILL REMAIN SUFFICIENTLY LOW TO ENHANCE DOWNDRAFTS...
AND SOME RISK FOR GUSTY SURFACE WINDS...BUT THIS SEEMS LIKELY TO
BECOME MORE SPORADIC IN COOLER/COOLING BOUNDARY LAYER. POTENTIAL
FOR MARGINALLY SEVERE HAIL WILL ALSO DROP OFF IN COOLER LOW-LEVEL
ENVIRONMENT WITH WEAKER LAPSE RATES IN CLOSER PROXIMITY TO THE
MISSISSIPPI RIVER.

..KERR.. 04/12/2006

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

ATTN...WFO...LSX...DVN...ARX...DMX...EAX...TOP...

42329329 43379286 43249109 43059089 42349053 41579058
40879081 40439123 39479224 38849372 38199599 39479474
40299390 41059332 

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