Area Forecast Discussion
Issued by NWS Rapid City, SD

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FXUS63 KUNR 211723
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1123 AM MDT THU JUL 21 2016

.SHORT TERM...Today Through Friday Night
Issued at 234 AM MDT Thu Jul 21 2016

Broad upper ridge remains over the central US, with westerly flow
over the top of the ridge across the northern plains. Weak wave
producing some showers across southeastern MT that may clip
northeastern WY and northwestern SD early this morning. Surface
low over central SD with cold front trailing across southwestern
SD-northeastern WY. Front will move through central SD by
afternoon, which could trigger some thunderstorms, as well as
over the southern Black Hills. Temperatures will be slightly
cooler today, and dewpoints will be lower over most of the
forecast area. Apparent temperatures will reach the low 100s
across central SD again, so the excessive heat warning will
continue through Friday. A wave moves from southern WY early
Friday into northwestern SD by Friday evening, while the lee trof
deepens across eastern MT-WY. Warm front may set up east to west
across northwestern SD with trailing cold front to the west.
Strong instability will be found along the trof, where CAPE values
will be around 2K j/kg. Temperatures will warm up again over
northeastern WY and far western SD, but will be a couple of
degrees cooler over central SD under the southeasterly return
flow, but higher dewpoints will keep the heat index values well
over 100. Front will cross western SD late Friday, producing
scattered thunderstorms across the area Friday night.

.LONG TERM...(Saturday Through Wednesday)
Issued at 234 AM MDT Thu Jul 21 2016

Following the cold front passage, northwest winds will
be breezy on Saturday, and temperatures for the weekend will be in
the 80s to lower 90s. Upper flow will be nearly zonal through the
extended, with periodic shortwaves bringing chances for showers and
thunderstorms. Temperatures will be near seasonal averages.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Friday)
Issued At 1122 AM MDT Thu Jul 21 2016

Isolated thunderstorms are possible across the central and
southern Black Hills and south-central SD this afternoon and
early evening. Any storm could produce brief MVFR CIGS/VSBYS.
Otherwise, VFR conditions will prevail through 18z Friday.

&&

.UNR Watches/Warnings/Advisories...
SD...Excessive Heat Warning until 6 PM MDT /7 PM CDT/ Friday for
     SDZ014-032-043-044-046-047-049.

WY...None.
&&

$$

SHORT TERM...55
LONG TERM...Pojorlie
AVIATION...Bunkers



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