Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 301711

Area Forecast Discussion
National Weather Service Sioux Falls SD
1111 AM CST Wed Nov 30 2016

.SHORT TERM...(Today and Tonight)
Issued at 258 AM CST Wed Nov 30 2016

Snow with the current lobe rotating around the MN upper low will be
mostly west of the area before decreasing later this morning. At
this time expect less than an inch in the Chamberlain to Gregory
area. Models indicate some drying and loss of ice before the
precipitation falls off as the lobe exits to the southeast. Went
with the modest GFS on this and melded with areas to the west, but
it appears not enough, or low level moisture is insufficient, to
bring freezing drizzle into the picture.

Another lobe is shown by models to swing south across the eastern
part of the area later this morning into the afternoon, as the upper
low moves slowly east from MN toward WI. Frontogenesis a little below
H850, and also in weaker form closer to H700, seems to support a
little enhancement of precipitation during the day in southwest MN.
High resolution models and model blends suggest enough precipitation
for 1 to 2 inches of snow in parts of southwest MN, with any daytime
accumulations especially sensitive to elevation. If the lobe becomes
stronger than forecast, we might have to deal with isolated 3 inch
amounts on the Buffalo Ridge.

Elsewhere today, light precipitation should be barely measurable if
that. The air appears cold enough to keep the precipitation mostly
snow, but even with that factor, there will be melting of snow at the
surface during the day, and it will be hard to get anything too
close to a half inch.

Breezy and cool conditions will continue, the cool part coming
mainly from the winds with these normal high temperatures,
especially after this mornings well above normal lows.

Clouds will remain tonight with precipitation ending as the upper
low moves further east of the area. There does not appear to be
enough support to suggest any snow accumulation more than a bare
dusting. Winds will very slowly subside, and temperatures will cool
only into the 20s...upper 20s east of the James River.

.LONG TERM...(Thursday through Tuesday)
Issued at 258 AM CST Wed Nov 30 2016

Quieter weather will settle over the region, with the slow moving
upper low finally exiting to the northeast. Weak northwest flow on
Thursday gradually turns more zonal Friday. Stratus will continue to
grip the area on Thursday and much of Friday. Northwest winds around
10 to 20 mph are expected Thursday morning, decreasing a little in
the afternoon. Temperatures both days will be fairly similar to
today, with highs in low to mid 30s. A weak shortwave dips across
northeast South Dakota late Thursday afternoon into the evening,
bringing a low chance of a narrow band of light snow or flurries
into the highway 14 corridor.

Weather becomes more active this weekend into early next week, with
a series of waves rapidly moving through the northern states. Models
show troughing digging into the northern high Plains Saturday night
into Sunday. Return flow develops Friday night and Saturday,
allowing clouds to begin breaking and warmer air advection to
return. Highs improve into the mid 30s to near 40 on Saturday, and
warm a few more degrees on Sunday as winds turns more westerly.
Models are trending towards keeping the bulk of the area dry with
the passing of this shortwave.

Another northern stream shortwave quickly follows around the Monday
night and Tuesday time frame. This system is less certain in its
track, with the GFS following a much more northerly projection than
the ECMWF. But with both solutions, it does look like areas east of
I29 have the better chance for precipitation Monday night. Tuesday
the ECMWF wobbles the upper wave over the upper Midwest while the
GFS keeps the low further north, but potentially brings southerly
stream energy into the central Plains. With cooler temperatures
arriving with the low Monday night and Tuesday, it looks like the
main precipitation type will be snowfall.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1107 AM CST Wed Nov 30 2016

Widespread MVFR and IFR conditions in stratus and light snow. The
light snow will gradually diminish from west to east through the
afternoon and evening, but the IFR stratus will remain in most
locations through the end of the TAF period.




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