Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 142054

Area Forecast Discussion
National Weather Service Sioux Falls SD
254 PM CST Tue Feb 14 2017

.SHORT TERM...(This evening through Wednesday)
Issued at 253 PM CST Tue Feb 14 2017

Conditions will remain quiet through Wednesday. Trough across the
Great Lakes will circulate a disturbance past well to the east this
evening, enough to keep some cold advection going and mixing gustier
winds through the evening over areas east of I-29. Mainly will see
some cirrus passing, but increasing mid-level warm advection could
bring a few thicker high or even a couple of mid clouds into
southwest MN by late night or early morning. A few rogue model
predictions of stratus into I-29 and east seem overdone for the
second straight night. Winds will diminish with surface ridge
stretching through the heart of the CWA by daybreak Wednesday, so
unless clouds are thicker than expected, should see a cooler night
in the upper teens to mid 20s, but this remains 5 to 10 degrees
warmer than normal.

Ridge will shift east and allow southerly flow to develop on
Wednesday. Fairly weak flow until perhaps the afternoon, but overall
mixing will be quite limited with the inversion marked by flow
veering all the way to west and northwest just a couple thousand
feet AGL. Has routinely been mixing a bit deeper than expected
during our warmer period, and have shaded temps a bit to the upper
end of guidance, as any deeper mixing will introduce a better
westerly component and utilize the stronger warming trend aloft.
Highs will vary from lower to mid 40s east of I-29, to the upper 50s
in south central SD.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 253 PM CST Tue Feb 14 2017

Wednesday night into Thursday will see a slow moving weak trough of
low pressure across the area. This will allow for fairly light winds
at night and a not too favorable mixing profile for Thursday.
However with very little cloud cover, very little snow cover and a
ground that is gradually drying the area should still see some very
mild days. Wednesday morning should see lows similar to this
morning, upper 20s to lower 30s, but with warmer temperatures aloft
daytime heating should take highs into the 50s, possibly some 60s in
south central SD.

Friday will see a very good chance for many locations to have high
temperatures 25 to 30 degrees above normal. This is due to a little
enhanced mixing ahead of a weak cool front that will drop south as a
wave moves through to ND into northern MN. Expect highs from the
upper 50s to mid 60s.

Friday night into Saturday will see a reinforcing shot of cooler
air, but with dry conditions and decent sunshine the effects will be
marginal. Lows upper 20s to lower 30s with highs in the 50s.

Saturday night into Monday will see a strengthening southerly flow
as a trough of low pressure deepens over the Rockies. This will keep
mild temperatures in place and will now start to have more of an
effect on low temperatures as well. In fact, Monday morning may see
some locations not fall below 50 degrees if the latest model output
is on target. That would be in the range of 30 to 40 degrees above
normal! Even Sunday morning and Tuesday morning should see lows from
about 35 to 45 degrees. High temperatures may take a little hit on
Monday as there appears to be a chance for some stratus to develop
and limit the diurnal range. So will stay a bit conservative on
highs Monday because of this. Still very agreeable to the rainfall
threat for Monday and while it is a bit to early to carry the threat
in the forecast, some thunder will be possible as model soundings
are hinting at some CAPE.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1135 AM CST Tue Feb 14 2017

VFR conditions will continue through 18z Wednesday. A few wind
gusts in excess of 25 knots will occur through 23z.




SHORT TERM...Chapman
AVIATION...Chapman is the U.S. government's official web portal to all federal, state and local government web resources and services.