Area Forecast Discussion
Issued by NWS Rapid City, SD

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FXUS63 KUNR 222317

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
517 PM MDT Tue Aug 22 2017

.DISCUSSION...(This Evening Through Tuesday)
Issued at 240 PM MDT Tue Aug 22 2017

Upper level ridge will keep the weather mild and mostly dry
through Wednesday night. The exception will be an isolated
thunderstorm or two over the Black Hills Wednesday afternoon.
After a clear and cool night tonight, mostly sunny skies are
expected on Wednesday with highs warming near 90.

On Thursday, a trough will begin breaking down the ridge over the
Pacific Northwest, and an approaching shortwave will interact with a
stationary boundary draped across the region. Showers and
thunderstorms are expected to develop mainly across the southwestern
half of the CWA. Precipitation will become more widespread on
Friday as the upper level shortwave tracks across northern
portions of South Dakota. Modest shear and instability will be in
place, possible producing a few stronger storms across the area.

Upper shortwave shifts east on Friday with another ridge building
over the west coast for Saturday. Both the ECMWF and GFS are
hinting at another weak wave bringing a few showers/storms to the
area Saturday, but generally a period of dry weather will begin
this weekend into early next week. Temperatures for the end of the
week through the weekend will be in the 80s.


.AVIATION...(For the 00Z TAFS Through 00Z Wednesday Evening)
Issued At 517 PM MDT Tue Aug 22 2017

VFR conditions are expected through the forecast period.




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