Severe Storm Outlook Narrative (AC)
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ACUS11 KWNS 240554
SPC MCD 240554

Mesoscale Discussion 0202
NWS Storm Prediction Center Norman OK
1154 PM CST Thu Feb 23 2017

Areas affected...Far eastern SD/NE...southern MN...northern IA...and
much of WI

Concerning...Winter mixed precipitation

Valid 240554Z - 241200Z

SUMMARY...A heavy snow band, with rates around 1 inch/hour, will
persist through 12Z. A mix of winter precip, including snow, sleet,
and freezing rain, will be possible across parts of northern IA into
southern WI.

DISCUSSION...An ongoing deformation band of moderate to heavy snow
across far eastern NE/SD into southern MN and northern IA is
associated with strong low and mid-level frontogenesis and related
ascent. As a shortwave trough over the northern/central Plains moves
northeastward overnight, the heavy snow band should likewise shift
northeastward across southern MN/northern IA, and into WI through
12Z. Snowfall rates around 1 inch/hour (locally higher) will be
possible within the core of the heavy snow band. Strong
northerly/northeasterly surface winds of 25-35 mph, with some higher
gusts, may allow for near-blizzard conditions, particularly across
parts of southern MN/northern IA where precipitation remains all
snow. A narrow corridor of mixed winter precipitation including
snow, sleet, and freezing rain may occur across parts of northern IA
into southern WI. Across this area, forecast soundings show a warm
nose aloft (generally between 850-700 mb) which should act to
partially/completely melt frozen hydrometeors. Sleet/freezing rain
rates will be convectively enhanced due to elevated instability and
thunderstorms moving across this area.

..Gleason.. 02/24/2017

...Please see for graphic product...


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