Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 162348

Area Forecast Discussion
National Weather Service Sioux Falls SD
648 PM CDT Fri Mar 16 2018

Issued at 643 PM CDT Fri Mar 16 2018

Sleet and freezing rain continue to use up more of the available
moisture for areas along and north of I-90. Snowfall amounts will
be much lower than previously forecast, but slick and potentially
dangerous driving conditions will still exist with freezing rain
changing to drizzle throughout the overnight hours.


.SHORT TERM...(This evening through Saturday)
Issued at 310 PM CDT Fri Mar 16 2018

Active forecast in the short term with band of precipitation lifting
to the northwest across the forecast area wrapping around a low
pressure center across eastern Nebraska. As frontogenetic band of
precipitation in the Missouri River Valley lifts to the north,
expect warm layer aloft to be less pronounced and precipitation type
to switch over to snow. Satellite suggests this band is quite
convective, and could see snowfall rates exceed 1" per hour rates
through the late afternoon into the early evening hours.  This
frontogenesis is expected to lift to the north, and then weaken
towards 06z as secondary band to the south takes over and support
dies away. Secondary band of precipitation developing near I-80 is
expected to expand and lift to the north will mainly stay south and
east of the forecast area.  The exception to this may be along
highway 20 in northwest Iowa where light precipitation will be
possible this evening.

As the upper level low weakens and shifts east, atmosphere dries out
from aloft.  With residual lift through deep saturated layer could
see some light drizzle/freezing drizzle through the evening hours.

Overnight, the lift dies away and residual cloud clover remains.
Have kept lows toward the mild side of guidance.

Temperatures will struggle to warm on Saturday with a healthy amount
of clouds around and light winds making it increasingly difficult to

.LONG TERM...(Saturday night through Friday)
Issued at 310 PM CDT Fri Mar 16 2018

Should see additional warming on Sunday ahead of the next weather
maker. Blended pops with this system appear to be fairly quick in
part to the GFS and in part canadian.  Prefer the slower timing of
the ECMWF, but was unable to make adjustments for now.

Relatively quiet weather expected much of next week.  A potentially
active pattern is shaping  up as a series of impulses break away
from an upper level trough over the Pacific NW.  Have not made
changes to the extended with active weather in the short term.


.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 643 PM CDT Fri Mar 16 2018

Freezing rain and sleet will transition to freezing drizzle
through the overnight hours. Expect ceilings to lower as the low
levels saturate overnight. IFR conditions are possible, with
widespread MVRF. Winds decrease and drizzle tapers off by
sunrise, with continued low clouds for most areas Saturday.


SD...Winter Weather Advisory until 1 AM CDT Saturday for SDZ038-039-

     Winter Storm Warning until 1 AM CDT Saturday for SDZ050-057-058-

MN...Winter Weather Advisory until 1 AM CDT Saturday for MNZ089-090-

IA...Winter Weather Advisory until 1 AM CDT Saturday for IAZ001>003-

NE...Winter Weather Advisory until 1 AM CDT Saturday for NEZ013-014.



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