Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 170827

Area Forecast Discussion
National Weather Service Sioux Falls SD
227 AM CST Tue Jan 17 2017

.SHORT TERM...(Today and Tonight)
Issued at 227 AM CST Tue Jan 17 2017

Still seeing widespread stratus and areas of fog from the Interstate
29 corridor and eastward very early this morning. RH time sections
show these low clouds only slowly eroding from the west into the
afternoon as drier airs filters into the region and the 925 mb flow
becomes more west/southwesterly during the day. Otherwise, a surface
ridge slides quickly across the region, with light northwesterly
winds early transitioning to southwesterly by afternoon. It will
still be a cool day with readings close to or just above normal for
this time of year, with highs generally upper 20s to lower 30s.

Tonight the surface ridge continues to push off to the east, with
light southerly winds and and any remaining clouds clearing out of
the area. In spite of the clear skies and light winds, temperatures
will remain tolerable in an ensuing warm air advection regime, with
lows mid and upper teens.

.LONG TERM...(Wednesday through Monday)
Issued at 227 AM CST Tue Jan 17 2017

Very few if any changes needed in the medium and extended portions
of the forecast. We`ll begin to see a January thaw begin quickly on
Wednesday as southerly flow pushes temperatures towards 40 degrees.
Concerns regarding upper system crossing the Central Plains
Wednesday night through Thursday are focused more on the increase of
low level moisture.  Increased probabilities of low stratus by
Wednesday night through Friday. Through collaboration have bumped up
cloud cover significantly.  Some signals for drizzle in soundings,
but decided not to pursue this yet.

Guidance continues to pull another system into the region by
Saturday. The dProg/Dt plots showing little variance with the track
of this system which should bring an increase in precipitation by
Saturday.  With overnight lows Friday into Saturday barely falling
towards the lower 30s, beginning to think this system will be more
cold rain than snow.

Quite a bit of uncertainty next week, but most guidance shows the
CWA between systems, with a stronger upper trough moving through the
lower MO river valley. See little risk of any significant cold air
into next week.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1049 PM CST Mon Jan 16 2017

Band of light freezing rain or freezing drizzle across southwest
MN and northwest IA will continue to dissipate over the next few
hours. Swath of MVFR and IFR low stratus will also slowly shift
eastward overnight, with clearing/VFR conditions expanding behind
it. Some patchy fog will also persist with the lower ceilings,
with some additional patchy fog possible near the KHON area late




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