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Area forecast discussion for western South Dakota and northeastern Wyoming 
National Weather Service Rapid City South Dakota
301 PM MDT Monday Apr 27 2015

Short term...this evening through Tuesday night
issued at 300 PM MDT Monday Apr 27 2015

Current surface analysis shows cold front stretching from
northwest Minnesota to south central South Dakota and western Nebraska. High pressure is
centered over far eastern Montana. Upper level analysis shows large
trough over the central Continental U.S....with low pressure over the Texas
Panhandle. Northern stream shortwave is located over western ND
into western South Dakota. Narrow shortwave ridge is finally breaking down
over the eastern Dakotas and Minnesota. Building ridge in place over the
West Coast. Skies remain mostly cloudy across much of northeast Wyoming
and western South Dakota...with mostly sunny skies over far south central South Dakota
ahead of the front. Kudx radar shows scattered to numerous light
showers right now from far northeast Wyoming through the Black Hills
area and across northwest South Dakota. Temperatures range from around 40 over
portions of northeast Wyoming and the Black Hills...to the upper 60s
ahead of the front across south central South Dakota. Northwesterly winds of
mostly 10 to 20 miles per hour across the area.

Clouds and showers will finally move out of the area tonight as
drier air moves in from the northwest behind the shortwave. Short
range models in good agreement on features...with main differences
coming with regard to when showers end tonight and when clouds
decrease. Mainly dry and warmer conditions can be expected midweek.

For tonight...skies will gradually clear from northwest to southeast
across the County Warning Area and showers will gradually taper off...ending late
tonight. Clouds could linger across far southern South Dakota into early
Tuesday if the drier does not push in quick enough. Lows will mostly
be in the 30s...with some lower 40s across south central South Dakota. As high
pressure slowly moves into the western Dakotas...winds will switch
to the south over northeast Wyoming overnight...while staying light and
variable or northerly across most of western and south central South Dakota.

On Tuesday...skies will be mostly sunny to partly cloudy as high
pressure moves across the Dakotas. South to southeast winds can be
expected across northeast Wyoming and far western South Dakota...while winds may
stay northerly across south central South Dakota through much of the day
before beginning to turn southeasterly. Have decided to add slight
chances for afternoon showers over the Black Hills as adequate
moisture remains with steep lapse rates developing. Highs will be in
the 60s across the plains...with middle to upper 50s over the Black
Hills. Skies will be mostly clear Tuesday night with lows in the middle
30s to middle 40s.

Long term...Wednesday through Monday
issued at 300 PM MDT Monday Apr 27 2015

Upper level ridge will bring dry and relatively warm weather to
the region Wednesday into Thursday. An upper wave is prognosticated to
cross the northern plains Thursday bringing a weak cold front to the
area along with some chances of showers and thunderstorms. Zonal
flow will set up behind the departing wave Friday and continue
through the weekend. Several waves are expected to cross the
region within the flow...with varying chances of showers and
thunderstorms. Temperatures will be near to slightly above
average.

&&

Aviation...for the 00z tafs through 00z Tuesday evening
issued at 300 PM MDT Monday Apr 27 2015

Rain showers will slide eastward and dissipate tonight.
MVFR conditions will also gradually improve across the NE Wyoming and western
South Dakota plains while IFR conditions over the Black Hills improve to
MVFR...then VFR tonight. VFR conditions will continue through
Tuesday.

&&

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

$$

Short term...26
long term...13
aviation...13

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