Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 092109

Area Forecast Discussion
National Weather Service Sioux Falls SD
309 PM CST Sat Dec 9 2017

.SHORT TERM...(This evening through Sunday)
Issued at 301 PM CST Sat Dec 9 2017

Surface winds have been slowly shifting to more westerly as a broad
area of warm advection moves through the region. This is in response
to a shortwave trough and associated low pressure moving from
southern Canada into the Great Lakes region. Westerly and
northwesterly breezes will actually slowly warm temperatures through
the overnight hours, setting us up for the warmest day of week

Sunday`s temperatures will run about 10-15 degrees above seasonal
averages. Locations west of I-29 should see some sun, but southwest
Minnesota will likely be caught under a more moist northwest flow.
This keeps the mid-level cloud cover around, keeping highs a bit
cooler. Southwest MN will likely reach the upper 30s, with south
central SD seeing mid 50s for afternoon highs.

.LONG TERM...(Sunday night through Saturday)
Issued at 301 PM CST Sat Dec 9 2017

The pattern for next week remains similar to this past week, with an
amplified trough over the eastern CONUS and a strong ridge over the
West Coast.

A weak cold front on Monday afternoon could bring light snow to much
of the tri-state area. Accumulations look very light, with less than
half an inch of new snow in favored areas, and only a dusting
elsewhere. Winds will also be breezy during the afternoon, with
gusts in the 30-35 mph range. Another shortwave moving southeast
in the meridional jet stream could move far enough west to bring a
second round of light snow Wednesday morning. However, models
such as the EC keep this system further east, would would keep our
area dry. Flurries are possible at times for the second half of
the week as well, but there is low confidence in the timing of
these features, given their weak and transient nature.
Temperatures remain roughly 5 to 10 degrees above average through
next weekend.

Models begin to hint at a subtle pattern change next weekend, with a
more progressive upper level flow. However, the ridge over the
eastern Pacific also shows signs of quickly rebuilding, which would
mean little change longer-term. Currently, no major weather systems
are expected through next weekend.


.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1131 AM CST Sat Dec 9 2017

Lingering broken mid-level cloud decks are forecast to erode early
this afternoon. A slight shift to more westerly winds will also
occur this afternoon, with a return to light northwesterly surface flow
after midnight. No precipitation is expected the next 24 hours.




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