4/11/07 Heavy snow alert

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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

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Have fun Changer :)