Area Forecast Discussion
Issued by NWS Rapid City, SD

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FXUS63 KUNR 120453

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
953 PM MST Thu Jan 11 2018

.DISCUSSION...(This Evening Through Thursday)
Issued at 121 PM MST Thu Jan 11 2018

Current surface map shows 1030+mb high across Saskatchewan into
the western Dakotas. Temperatures range from around zero in
northwest South Dakota to teens in higher elevations of the Black
Hills and northeast Wyoming.

Shortwave crosses the area tonight with weak isentropic lift.
This will bring some light snow/flurries tonight/Friday.
Accumulations will be minimal...1/2" or less. Temperature/wind
combination tonight/Friday morning will keep wind chills down to
-20F to -30F.

Reinforcing surge of arctic air arrives tomorrow, with center of
1040+mb high dropping into the Dakotas Friday night. The high
quickly slides east Saturday, allowing warm front to push into
western South Dakota. Some uncertainty to how quick the plains of
western South Dakota will warm up, but Black hills and northeast
Wyoming will see highs in the 30s. Mild day expected across the
area Sunday. Upper trof rotating around Hudson Bay low will drop
into the Dakotas late Sunday/Sunday night. This will bring another
round light of snow as arctic front backs into the forecast area.

Models in decent agreement for middle of next week, with upper
level ridge shifting across the northern plains. Above average
temperatures expected for much of the area Wed-Thur.


.AVIATION...(For the 06Z TAFS Through 06Z Friday Night)
Issued At 951 PM MST Thu Jan 11 2018

MVFR conditions will develop from west to east overnight as light
snow develops. The MVFR conditions with light snow will persist
through Friday morning. Light snow will then end from west to
east Friday afternoon, but MVFR cigs will likely persist in most
areas through the afternoon.


SD...Wind Chill Advisory until 11 AM MST Friday for SDZ001-002-



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