Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 082325

Area Forecast Discussion
National Weather Service Sioux Falls SD
525 PM CST Fri Dec 8 2017

.SHORT TERM...(This evening through Saturday)
Issued at 309 PM CST Fri Dec 8 2017

Northwest flow continues over the region through tonight, with a
slight chance for flurries in southwest MN, as a shortwave trough
moving over the eastern part of Minnesota may bring just enough
moisture and lift. No additional accumulations are forecast.

Skies clear somewhat overnight with radiational cooling leading
to a slightly cooler start to Saturday than Friday. Northerly
advection of a cooler air mass may keep temperature readings a
degree or two shy of Friday`s highs, but overall, it will feel
like a very similar day to Friday. One subtle change will be a
shift to westerly winds by the evening, which will set us up for
the warmest day of the week Sunday.

.LONG TERM...(Saturday night through Friday)
Issued at 309 PM CST Fri Dec 8 2017

No major weather pattern changes or weather system are expected over
the next 7 days, with a strong upper-level ridge over the West and a
longwave trough over the eastern CONUS.

Sunday looks to be the warmest day of the next 7, as the longwave
trough that has been stationary over the Great Lakes region briefly
nudges eastward, allowing the ridge and higher geopotential heights
to migrate eastward over the tri-state area. Low 40s are forecast
for southwest MN, warmer as one heads west, with up to mid 50s
for south central SD.

Monday will bring a return to breezy northwest winds, gusting in
the 30 to 40 mph range, and temperatures closer to seasonal
averages, but still above normal. By the afternoon, some light
snow is possible east of I-29 as another weak shortwave trough
translates south through MN and WI in the meridionally-oriented
jet. Models are in agreement that any accumulations should remain
light, given how far east the system is relative to our area.

Tuesday and Wednesday of next week look dry, with slightly-above-
seasonal temperatures continuing. The next chance for flurries or
light snow may be Thursday, as another weak shortwave trough moves
southward well to our east. Confidence is low on timing and
temperatures with this system, as model spread remains large.


.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 521 PM CST Fri Dec 8 2017

The primary challenge for the 00Z TAF set is the potential for
MVFR stratus late tonight and Saturday morning. Several models are
showing stratus backing down from the north/northeast from about
06Z onward, with enough potential that it was included for the
KFSD site. This scenario is plausible as MVFR stratus currently
exists in west central and central MN behind a short wave moving
through Minnesota. Problematic is the KHON and KSUX TAF sites,
where some members showed MVFR stratus while others did not. This
will be reevaluated as the evening progresses and stratus may
have to be included at one or both of these sites for the 06Z TAF
set, as current confidence is low. For now, hedged at KHON and
KSUX with a scattered deck in the MVFR range.




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