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Area forecast discussion for western South Dakota and northeastern Wyoming 
National Weather Service Rapid City South Dakota
419 am MST Friday Nov 27 2015

Short through Saturday night
issued at 204 am MST Friday Nov 27 2015

Water vapor shows persistent cutoff upper low over the Great Basin
with a col (very light winds) over the northern plains. At the
surface...strong high covers Montana into the Dakotas.

Today...plenty of sunshine expected but cold temperatures will prevail
with surface high covering the northern plains. Winds will be relatively

Saturday...a strong middle/upper level impulse will eject from the
Great Basin low and provide broad but weak lift across Wyoming/western
South Dakota/Nebraska Panhandle. This lift atop the cold dome at the surface will
bring an inch or two of snow to northestern Wyoming...the Black Hills...and southwestern
South Dakota. High temperatures will be near or a few degrees warmer than today.
Snow will diminish by Saturday night.

Long term...Sunday through Thursday
issued at 204 am MST Friday Nov 27 2015

Medium range models in decent agreement at this point
for the extended period. Upper level low will be situated over the
northern and central rockies Sunday...then move east across the
plains early next week. Chances for snow will increase later Sunday
and Sunday night...with widespread chances for snow Monday and
Monday night as the low tracks across the region. Have increased
probability of precipitation for much of the County Warning Area during these periods. There are still some
timing and track issues with the models...but some accumulating snow
is looking increasingly likely for a good portion of County Warning Area during this
time...especially across South Dakota. Temperatures will remain below average
Sunday through Tuesday.

As the low moves east of the region by Tuesday night...upper level
ridging will move across The Rockies and into the plains for the
middle and latter part of the week. This will bring mainly dry and
milder weather. Temperatures should at least be near average levels for the
latter part of the week.


Aviation...for the 12z tafs through 12z Saturday morning
issued at 419 am MST Friday Nov 27 2015

Patchy MVFR/IFR ceilings are possible across northeast Wyoming and far
southwest South Dakota early this morning. Otherwise...VFR conditions will
generally persist today and into this evening as high pressure
moves across the northern plains.


Unr watches/warnings/advisories...
South Dakota...none.


Short term...Johnson
long term...26

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