Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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342
FXUS63 KFSD 152342
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
542 PM CST Wed Nov 15 2017

.SHORT TERM...(This evening through Thursday)
Issued at 240 PM CST Wed Nov 15 2017

A rather quiet forecast continues through the weekend and into next
week.  The primary areas where forecast changes were made include:

1. Increasing wind speeds from Thursday through Saturday.
2. Slight modifications to PoPs for Friday and Friday night.

Tonight: High pressure drift into the area and stratus over the
eastern portions of the forecast area will slowly dissipate this
evening.  Still anticipating the western flank of this cloud cover
to be near the CWA, but may likely stay in the Minnesota River
valley. Warm advection aloft will begin to allow high level cloud
cover to stream northeast after midnight, and may see temperatures
steady through the night.

Thursday: An 850 mb trough approaches the area through the day,
inducing strong warm advection signatures through the day and the
expectations of a very cloudy day, albeit with mid-level clouds.
Southeast winds begin to increase in the morning, with soundings
suggesting gusts to 30-40 mph spreading east by the afternoon
hours. Have blended in high MOS and ARW guidance for the winds
into the weekend.

.LONG TERM...(Thursday night through Wednesday)
Issued at 240 PM CST Wed Nov 15 2017

Thursday night: A veering wind profile will allow strong winds to
persist into the evening, with enhanced winds over the Buffalo Ridge
through the night. ARW/NMM higher resolution guidance helped pick
out these risks better than other blends.

Friday: Models have really backed off on precipitation chances for
Friday. Surface troughing slides into the area early Friday morning,
which should promote the northward advection and development of
stratus through the day.  This stratus could have a profound impact
on temperatures. Precipitation chances, despite the favorable lift,
will be confined to the far southern portions of the CWA, and even
there, there is a fairly thin layer of saturation in the lower layer
which would favor more drizzle as opposed to rain.

Saturday:  A cold front surges southeast by Saturday morning,
pulling cold temperatures into the region. Soundings indicate that
momentum transfer winds up to 30 knots could be possible by mid-day
and the afternoon.  Cold advection aloft could even set the stage
for isolated diurnal based instability showers or snow showers in the
afternoon.

Sunday-Wednesday: A very progressive flow pattern persists into next
week, with expectations of a temperature rollercoaster ride
continuing.  There remain no strong precipitation risks through the
middle of the week.  For those looking ahead to Thanksgiving travel,
just know that after 180 hours model discrepancies become very
significant with a 3 to 6 standard deviation noted in numerical
guidance.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 538 PM CST Wed Nov 15 2017
VFR conditions expected through the period. Gust northwest winds
should subside quickly this evening, and remain light overnight.
Winds will increase out of the south on Thursday, becoming gusty
in the late morning and afternoon hours.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.
&&

$$

SHORT TERM...Dux
LONG TERM...Dux
AVIATION...BT



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