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fxus63 kunr 231041 

Area forecast discussion for western South Dakota and northeastern Wyoming
National Weather Service Rapid City South Dakota
441 am MDT Tue Jul 23 2019

Discussion...(today through monday)
issued at 130 am MDT Tue Jul 23 2019

Water vapor shows upper ridge axis through the northern rockies
with some embedded monsoonal moisture. At the surface, ridge is
located over the eastern Dakotas with Lee trof from central Montana
through central Wyoming. A bit of mid/high clouds tracking through the
ridge into the forecast area.

Another dry day in store with large scale subsidence in place from
the upper ridge. Anything coming off the big horns will struggle
to make it into Campbell County. However, there could be enough
heating in the Black Hills to overcome the broad subsidence to
produce a storm or two. MLCAPE around 2000j/kg with only modest
shear would suggest more pulse type storms should they develop.
High temps well into the 80s expected, and combined with
increasing low level moisture conditions will become somewhat

Wednesday will likely be the hottest and most humid day of the
week with thermal ridge overhead. Many plains locations will rise
into the lower 90s. Could see some late day storms as the
approaching trof works into our western zones while pac northwest trof
moves into The Rockies. MLCAPE of 2000-3000j/kg along with
increasing shear will be enough for a few severe storms in our
western zones. Some activity may spill into the South Dakota plains
Wednesday night.

Upper trof works through the northern plains Thursday with mainly
zonal flow through the duration of the extended period. This will
lend to chances for storms at times although moisture seems to be
somewhat limited. Temps will likely be near or slightly above
average most days.


Aviation...(for the 12z tafs through 12z Wednesday morning)
issued at 440 am MDT Tue Jul 23 2019

A few rain showers/thunderstorms and rain cannot be ruled out over the Black Hills this
afternoon, which could bring localized MVFR conditions. Otherwise,
VFR conditions will prevail through the period.


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

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