Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 060929

Area Forecast Discussion
National Weather Service Sioux Falls SD
329 AM CST Tue Dec 6 2016

.SHORT TERM...(Today and Tonight)
Issued at 326 AM CST Tue Dec 6 2016

Cold air blast under way across the region as first arctic airmass
of the season arrives. Along with the cold air advection, low
stratus will also sink southward, likely coming to rest along or
just south of I90 by late morning. With the cold airmass placing the
low stratus well into the dendritic layer, expect some isolated
light snow or flurries to develop north of I90, with the best
potential in the highway 14 corridor. Do not expect much of any
accumulation, with perhaps a dusting or a few tenths possible near
highway 14.

The main story will be the strong northwest winds associated with
the cold push. Winds will be near advisory level, potentially
sustained around 25 to 35 mph north of I90, with gusts to 45 mph.
Think there is enough potential for advisory level winds for a
headline late morning into the early evening, especially given
the near advisory level winds already occurring early this
morning. Temperatures have dropped into the teens and lower 20s at
this hour and will likely remain somewhat steady or rise a few
degrees at best today. With the strong winds, wind chill values
will sit in the single digits above and below zero all day.

Tonight, stratus starts lifting northward, but secondary trough digs
into Nebraska overnight, bringing some additional cloud cover
towards daybreak. Cold air advection continues overnight, with winds
only decreasing slightly overnight. Expect winds of 15 to 25 mph
with higher gusts. Lows will be some of the coldest of the season,
bottoming out around 5 to 15 degrees above zero.

.LONG TERM...(Wednesday through Monday)
Issued at 326 AM CST Tue Dec 6 2016

Gusty northwest winds are expected to remain across the plains
through Thursday as strong northwest flow prevails drawing cooler
air into the region.  Have continued to raise winds over guidance
values under the cold air advection regime, and raise wind gusts.
Northwest flow continues to be dirty.  While models remain dry,
still some shortwaves dropping through.  Any low level saturation
would have the potential to produce light flurries. Have continued
to highlight the strongest of these waves with a mention of flurries
Thursday across southwest Minnesota.

Could see some additional flurries on Friday as warm air starts to
work into the region an overruns the cold air at the surface.  Have
not added mention of it in the forecast, but need to keep an eye on

A series of fast moving waves are expected to moves through Friday
night into Saturday.  While there is not a lot to grasp onto in
terms of dynamics and moisture, still could see some periods of
light snow and have kept chance mention in the forecast.  Have
removed pops from the Friday night time frame where there will be
moisture issues, and in a perfect world, would like to concentrate
the pops on Saturday as trough moves through the region.

Northwest flow prevails on Sunday, keeping the diurnal range small.
After a cool night Sunday night into Monday morning with high
pressure overhead, temperatures should warm nicely on Monday as
southerly flow increases throughout the day.

Strong cold front is expected once again on Tuesday of next week,
and have lowered forecast highs with temperatures likely to be
steady if not falling throughout the day.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1035 PM CST Mon Dec 5 2016

MVFR are beginning to break up from the west, and guidance is
suggesting these clouds to scatter out through the night, though
returning around KHON after 10z. There could be light snow in
areas through the northern Highway 14 corridor on Tuesday.
Northwesterly winds will continue to be strong, gusting to 30 to
35 kts through late Tuesday afternoon.




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