ZCZC SPCSWOMCD ALL
ACUS11 KWNS 221111 
SPC MCD 221111 
WIZ000-ILZ000-IAZ000-221515-

Mesoscale Discussion 0281
NWS Storm Prediction Center Norman OK
0611 AM CDT Fri Mar 22 2024

Areas affected...Northeast IA to the IL/WI border

Concerning...Heavy snow 

Valid 221111Z - 221515Z

SUMMARY...A narrow band of heavy snow developing in north-central
Iowa should shift east across parts of northeast Iowa towards the
Illinois-Wisconsin border through late morning. Rates of 1-2"/hr
should be expected, but may remain of relatively short-duration at
any one location.

DISCUSSION...The north side of a high-reflectivity convective plume
across central IA appears to have finally cooled enough to maintain
all snow to the surface, per recent surface observations and DOT
cameras. 03Z SREF probabilities and 00Z HREF snowbands guidance have
been highly insistent that a relatively narrow (around 25 miles
wide) heavy snow band should translate east, likely centered on the
US-20 corridor per observational trends. This suggests heavy snow
will be of relatively short duration at any one location, but
snowfall rates should easily reach 1-2"/hr given the focused 700-mb
frontogenesis beneath the dendritic growth zone and the deep, nearly
isothermal layer just below freezing to the surface.

..Grams.. 03/22/2024

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...LOT...MKX...DVN...ARX...DMX...

LAT...LON   42479377 42669334 42839235 42899085 42918998 42868936
            42748915 42528915 42298930 42188951 42159017 42019145
            42059249 42099316 42239373 42479377 

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