MESOSCALE DISCUSSION 0453
   NWS STORM PREDICTION CENTER NORMAN OK
   0730 AM CDT WED APR 11 2007
   
   AREAS AFFECTED...CENTRAL/ERN IA..SRN WI AND FAR NRN IL
   
   CONCERNING...HEAVY SNOW 
   
   VALID 111230Z - 111830Z
   
   HEAVY SNOW WITH OCCASIONAL 1 IN/HR RATES WILL DEVELOP ACROSS THE
   AREA THROUGH THE REMAINDER OF THE MORNING.
   
   THE LEFT EXIT REGION OF A STRONG UPPER JET ROTATING THROUGH SRN MO
   AND AR WAS CONTRIBUTING TO STRONG UPPER LEVEL ASCENT DEVELOPING OVER
   MUCH OF THE MID MO VALLEY IN THE LAST FEW HRS. AS A RESULT OF
   INCREASING UPPER DIFFLUENCE...LOW-MID LEVEL FRONTOGENETIC FORCING
   HAS BEGUN TO INTENSIFY N-NE OF A LOW-MID LEVEL CYCLONE /LOCATED OVER
   MO/ ACROSS PORTIONS OF CENTRAL/ERN IA AND SWRN WI. AS THIS LOW-MID
   LEVEL LOW CENTER CONTINUES TO LIFT ENEWD TOWARDS THE AREA OF MAX
   PRESSURE FALLS /OVER NRN IL PER RECENT SFC ANALYSIS/ THROUGH THE
   REMAINDER OF THE MORNING...EXPECT A CONTINUATION OF BANDED SNOWFALL
   /HEAVY AT TIMES/ ASSOCIATED WITH THE MID LEVEL DEFORMATION ZONE TO
   DEVELOP ALONG A 50-100 MILE CORRIDOR ENEWD INTO SRN WI/FAR NRN IL.
   GIVEN STRONG LIFT AND STEEP MID LEVEL LAPSE RATES IN THE DENDRITIC
   SNOW GROWTH LAYER COUPLED WITH THE PRESENCE OF A DEEP ISOTHERMAL
   LAYER IN THE LOWEST 2-3 KM /PER THE 12Z DVN SOUNDING/ AND MODERATE
   TO HIGH PWAT FEEDING INTO THE SYSTEM...HRLY SNOWFALL RATES AROUND 1
   INCH WILL BE POSSIBLE.
   
   ..CROSBIE.. 04/11/2007
   
   
   ATTN...WFO...LOT...MKX...DVN...ARX...DMX...
   
   43609126 43129272 42109367 41729369 41419344 41319302
   41499199 41869125 42129040 42398832 42758751 43368737
   43738847 43789028