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Area forecast discussion for western South Dakota and northeastern Wyoming 
National Weather Service Rapid City South Dakota
228 am MDT Friday Jul 29 2016

Short term...(today through Saturday night)
issued at 227 am MDT Fri Jul 29 2016

Persistent active NW flow will support yet more chances for
showers and thunderstorms in parts of the fa through the period.
Lingering/exiting mid level vort Max over scentral South Dakota continues to
support sct shra there this morning. Otherwise, moist bl with
clearing has allowed for patchy fog across the region. Fog will
persist through mid morning, before burning off. Attention turns
toward the next impulse now over NW Montana. This feature is expected
to time over the fa mid afternoon, and when coupled with diurnal
heating will support sct/isold shra/ts over much of the fa, most
numerous over the Black Hills. A few of the hires models have
indicate one or two stronger and potentially severe cells over the
Black Hills, which is not out of the question given progged ml
CAPES aoa 1000 j/kg with over 40 knots of deep layer shear.
Shra/ts chances may linger through the night over the se third
with the slowly exiting impulse. Easterly flow may once again
support areas of fog after midnight.

Saturday looks to be a similar setup to Friday with another weak
impulse expected in NW flow. Models do indicate a bit more cape
than today, esp over the southern third, possible supporting a few
stronger cells. Any convection remaining in the evening may carry
overnight given a developing llj over scentral South Dakota.

As for temps, slightly warmer but still seasonal conds expected
today with 80s most areas. Waa will allow warmer temps Sat with
90s expected on the plains.

Long term...(sunday through thursday)
issued at 227 am MDT Fri Jul 29 2016

Weak upper level ridge slides across the northern plains Sunday as
upper low moves into southwestern Canada. With marginal instability,
there is a chance for a few thunderstorms. Upper low continues to
move eastward across southern Canada early next week, with
increasing west-southwest mid level flow across the northern plains.
Series of weak impulses will bring a daily chance of thunderstorms.
Temperatures will be cooler mid-week, but still above average.


Aviation...(for the 12z tafs through 12z Friday night)
issued at 227 am MDT Fri Jul 29 2016

Areas of IFR/LIFR conditions with status and fog will be located
over parts of far northeastern Wyoming and western through south
central South Dakota through this morning, with conditions becoming
VFR by late morning. Scattered showers and thunderstorms will occur
this afternoon and evening with local IFR visibility.


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


Short term...jc
long term...7

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