Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 221521
SWOMCD
SPC MCD 221520
WIZ000-MNZ000-IAZ000-NEZ000-SDZ000-222115-

Mesoscale Discussion 0039
NWS Storm Prediction Center Norman OK
0920 AM CST Mon Jan 22 2018

Areas affected...Portions of eastern NE...far southeastern
SD...northern/western IA...southern MN...and western WI

Concerning...Heavy snow

Valid 221520Z - 222115Z

SUMMARY...Heavy snow, with rates around 1-2 inches per hour, will
spread northeastward through this afternoon. Blizzard conditions
will continue across parts of eastern NE into far southeastern SD,
western/northern IA, and southern MN for at least a few more hours.

DISCUSSION...A mature mid/upper-level cyclone centered over eastern
NE/KS this morning will move east-northeastward across IA/MO and
towards IL by later today. A zone of strong low/mid-level
frontogenetic forcing on the northern extent of this cyclone is
supporting a band of moderate to heavy snow extending from eastern
NE into western/northern IA and southern MN. This heavy snow band
will develop northeastward into more of southern MN and eventually
parts of western WI by this afternoon. Snowfall rates of 1-2 inches
per hour will be common within this band, with locally higher rates
possible within where localized convective enhancement occurs.
Sporadic lightning strikes may continue given the very strong
large-scale forcing and steepened mid-level lapse rates.

Additionally, a strong surface pressure gradient exists on the
northern side of a low centered over IA as of 15Z, which is
supporting blizzard conditions across parts of eastern NE, far
southeastern SD, western/northern IA, and southern MN. Here,
frequent northerly/northeasterly gusts of 35-50 mph are resulting in
blowing snow with substantially reduced visibilities (1/4 of a mile
or less). These blizzard conditions are expected persist for at
least the next few hours.

..Gleason.. 01/22/2018

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

ATTN...WFO...ARX...MPX...DMX...FSD...OAX...GID...

LAT...LON   44029142 43629235 43279342 42579519 41119622 40939779
            41659826 42779779 44239582 45189339 45459190 45279101
            44379085 44029142



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