Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 100452
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
1052 PM CST Fri Dec 9 2016

.SHORT TERM...(This evening through Sunday night)
Issued at 318 PM CST Fri Dec 9 2016

Still looking at the potential for a little light snow across the
area this evening. Overall should be an unfocused threat with
locations receiving a quarter inch of snow or less. Basically
looking at some low level moisture which is collocated with the
dendritic layer so pretty easy to get some occasional flurries.

Between the exiting wave to the northeast and the incoming wave to
the northwest southerly flow in the low to mid levels will gradually
increase through the night into Saturday morning. This should allow
for snowfall to begin developing to the southwest, then spread
across all of southeast SD into southwest MN and northwest IA during
the late morning. While there are some hints of instability above
the 800 to 700 mb layer it is not a good signal nor is it very
organized so still leaning towards a broader band of light to
moderate snow, continuing to look more like an unfocused isentropic
upglide type of system. This supports a larger coverage of snowfall
and should avoid any excessive snowfall amounts over 10 inches. If
any banding can occur the hints seem to be on Saturday night with a
focus over northwest Iowa so that will be something to watch. With
the slower movement of the upper level wave expect snow to not come
to an end until late morning or early afternoon Sunday. This should
leave behind about 1 to 3 inches of snow in central SD, 4 to 6
inches in far eastern SD and 5 to 8 inches over parts of southwest
MN into northwest IA.

Temperatures not expected to change much through Sunday, generally
teens and 20s for lows and highs Friday night into Sunday with
snowfall and less cold air mass yet to be pushed southeast.

.LONG TERM...(Monday through Friday)
Issued at 318 PM CST Fri Dec 9 2016

Quieter weather, but bitter cold conditions will mark the long range
forecast. Broad trough with an arctic connection swings southward
into the central US on Monday, with several reinforcing shots of
cold air dropping into the region through the upcoming week. With
fresh snowpack expected to blanket the area, expect temperatures to
be even colder than the most recent cold plunge. Monday will likely
be the warmest day of the week, with highs in the mid teens and 20s
ahead of the upcoming cold plunge. Cold front moves through the area
on Monday afternoon and evening, but moisture remains quite meager,
especially south of I-90. Will leave a slight chance of snow
near near the highway 14 corridor.

Tuesday into Friday will see high temperatures mainly in the single
digits or lower teens. Lows overnight will likewise mainly fall into
the single digits below zero. With models not having a good handle
on the amount of snowpack, went ahead and dropped temperatures a
little below blended guidance. Blustery winds will also be a
concern, especially Wednesday and Wednesday night, where breezy
conditions will drop wind chills into the -20 to -30 range in areas.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1052 PM CST Fri Dec 9 2016

An area of very light snow or flurries with patchy MVFR conditions
will gradually be overtaken by prolonged light to moderate snow
which will spread into southeast South Dakota prior to daybreak
Saturday. The light to moderate snow will then expand east into
southwest Minnesota and northwest Iowa throughout the day Saturday,
while it diminishes through the Missouri River Valley. Visibility and
ceilings will both be reduced during snowfall. IFR conditions be most
likely, though periods of LIFR visibility will be possible at times.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory from 9 AM Saturday to noon CST Sunday
     for SDZ040-055-056-062-066-067-071.

     Winter Weather Advisory from 6 AM Saturday to 9 AM CST Sunday
     for SDZ039-053-054-059>061-065.

MN...Winter Weather Advisory from 9 AM Saturday to noon CST Sunday
     for MNZ071-072-080-081-089-090-097-098.

IA...Winter Weather Advisory from 9 AM Saturday to noon CST Sunday
     for IAZ001>003-012>014-020>022-031-032.

NE...Winter Weather Advisory from 9 AM Saturday to noon CST Sunday
     for NEZ014.

&&

$$

SHORT TERM...08
LONG TERM...
AVIATION...JH


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