Area Forecast Discussion
Issued by NWS Rapid City, SD

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FXUS63 KUNR 010535

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1035 PM MST Tue Feb 28 2017

.SHORT TERM...(This Evening Through Wednesday Night)
Issued at 235 PM MST Tue Feb 28 2017

Current surface analysis shows nearly stationary frontal boundary
hanging from southeast MT through the Black Hills area. Upper
level analysis shows trough now over the northern high plains,
with strong jet remaining from the Central Rockies to the Upper
Midwest. Skies are mostly cloudy across much of the area, with
some sunshine over portions of northeast WY to far southwest SD.
Patchy fog lingers in a few areas to the north and east of the
Black Hills. Snow showers have started to develop over portions of
eastern MT, northeast WY, and into the Black Hills. Temps are in
the 30s to the south and west of the boundary, 20s to the north
and east.

Unsettled and cool weather will continue through the short term as
trough crosses the area late today and tonight, with northwest flow
aloft in place through the rest of the period. Snow showers are
possible through this evening, mainly near and east of the frontal
boundary, as trough crosses the region. Showers should mostly be on
the lighter side, but light accumulations are possible in spots,
especially over the Black Hills. Activity should taper off by late
evening as trough exits. The trough will help to push the boundary
north and eastward across western SD overnight. Lows will generally
be in the mid teens to mid 20s with winds switching around to the
west and northwest.

Low pressure will slide east along the boundary on Wednesday as the
front lingers from southeast MT to eastern SD. Tightening pressure
gradient will help to produce gusty winds across the plains,
especially the SD plains, late tonight and on Wednesday. Highs will
be in the 30s and lower 40s, with some 20s across the higher Black
Hills. A weak disturbance aloft in northwest flow will push across
far northeast WY, the Black Hills, and northwest SD late Wednesday
and Wednesday night, bringing a chance for mostly snow showers.

.LONG TERM...(Thursday Through Tuesday)
Issued at 235 PM MST Tue Feb 28 2017

Northwest flow aloft early in the period will bring seasonable
temperatures on Thursday. Upper level ridge will build over the
region Friday and the weekend, bringing above average temperatures
to the region. Highs over the weekend look to be in the 50s and
60s. A strong cold front and shortwave will cross the region
Sunday night into Monday, bringing a chance for pcpn and gusty
winds. Medium range models in some disagreement behind this
system, with EC bringing warmer air back on Tuesday, while the GFS
keeps cooler air around into midweek. Will side more with the EC
at this point.


.AVIATION...(For the 06Z TAFS Through 06Z Wednesday Night)
Issued At 1029 PM MST Tue Feb 28 2017

Isolated to scattered snow showers are possible across far
northeast WY and the Black Hills area tonight. MVFR conds will be
possible in heavier showers. Otherwise, areas of MVFR/IFR conds
will be possible on the SD plains ahead of a sfc trough. Gusty NW
winds will develop behind the trough, supporting a trend to VFR
conds all places Wed.




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