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Area forecast discussion
National Weather Service Sioux Falls South Dakota
521 am CST Mon Dec 9 2019

Short term...(today and tonight)
issued at 303 am CST Mon Dec 9 2019

A strong cold front will continue to move eastward across the region
this morning, bringing light snow and gusty winds. Model guidance
remains in good agreement regarding the lift and moisture in this
open wave, and storm total snowfall is still expected to be the 1 to
3 inch range for most locations, ending mid morning. All locations
will be windy today, but locations around Sioux City Iowa and
northeast NE will likely see the strongest gusts during the am
hours, with intense pressure rises already generating gusty winds
upstream. The winds are expected to be just below Wind Advisory
criteria, but will blow snow around nevertheless and may reduce
visibility at times.

The well-advertised cold air moves in today, with today's high
temperatures already having been recorded near midnight. Teens and
single digit temperatures abound this afternoon, with wind chills
in the negative teens. Be sure to bundle up if outside, even
during the daytime hours. Temperatures continue to cool overnight
into Tuesday. It's Worth noting that a few hours of saturation in
the dendritic growth layer overnight could bring widespread
flurries, but very little accumulation is expected.

Long term...(tuesday through sunday)
issued at 303 am CST Mon Dec 9 2019

The chilly Canadian air mass remains in place until Thursday,
with a few weak weather systems bringing the potential for
additional flurries and very light snow accumulation Tuesday night
and Wednesday night. Both of these shortwaves are quite subtle,
but favorable temperature profiles and the region being under an
active jet stream aloft give potential for seeing periods of light

On Thursday the deep trough over the eastern Continental U.S. Will exit east
over the Atlantic, and allow a more progressive westerly flow aloft.
At the surface, southerly return flow on the upstream side of the
surface high will begin to usher in a more seasonal air mass,
with highs in the mid 20 to mid 30s. The jet remains in the
vicinity Thursday and Friday, making it hard to be sure any given
time period will be completely dry, but no major systems are
expected. Nevertheless, subtle shortwaves moving through the flow
will necessitate keeping slight chance pops in place. Model begin
to diverge for the weekend, with some forming another deep trough
over the Great Lakes, which would favor another period of well
below average temperatures. However, the European model (ecmwf) keeps this trough
lower amplitude, which would allow for more mild weekend
temperatures. Confidence in this portion of the forecast is
currently low given these differences.


Aviation...(for the 12z tafs through 12z Tuesday morning)
issued at 517 am CST Mon Dec 9 2019

A cold front with light snow will continue to push eastward east
of I-29 through the morning hours. By noon, new accumulating snow
will have ended, with ceilings improving rapidly. However, some
surface obscuration may still occur due to blowing snow and
continued northwesterly wind gusts to 30 kt. Winds decrease after
sunset, and will shift to southerly for the overnight hours.
Additional flurries and very light snow is possible as mid level
clouds increase overnight into Tuesday morning.


Fsd watches/warnings/advisories...
South Dakota...none.

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