Area Forecast Discussion
Issued by NWS Rapid City, SD

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000
FXUS63 KUNR 250749
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
149 AM MDT THU AUG 25 2016

.SHORT TERM...(Today Through Friday Night)
Issued at 147 AM MDT Thu Aug 25 2016

Upper low spins over southern Manitoba, with trough stretching
across much of the ConUS. There is some weak shortwave energy over
WY, and some scattered showers over northeastern WY and western
SD. At this surface, high pressure is moving into the region from
the northwest. Winds are northwesterly around 10 mph, and
temperatures are in the 50s.

Initial trough will dissipate into westerly flow today, while a
secondary trough sets up over the Rockies. Showers will continue
this morning over portions of the CWA as shortwave crosses the area.
Overall precip chances will decrease this afternoon, although
showers/storms may continue around the Black Hills area with some
weak instability there. Cool 850 mb airmass will keep highs below
average today, ranging from the 60s across the Black Hills and
northeastern WY to the lower 70s across south central SD.

Chances for showers and isolated thunderstorms will increase
tonight, as upper trough begins to move across the northern plains.
Return flow sets up as surface high pushes east, allowing more
moisture to advect into the area.

Showers and thunderstorms will continue on Friday. Thermal ridge
will start moving toward the region, and temperatures will warm
slightly into the 70s. Models are showing 500-1000 J/kg MLCAPE
developing by 21Z, mainly along the WY/SD border. HiRes convective
models have first area/band of showers/storms moving over central SD
by 00Z, with another line of storms developing over northwestern
SD/northeastern WY along a boundary. With 0-6 km shear around 35
kts, storms may become strong to severe. Showers/storms will
diminish Friday night.

.LONG TERM...(Saturday Through Wednesday)
Issued at 147 AM MDT Thu Aug 25 2016

The upper trough will exit the area on Saturday, pushing
precipitation to the east and keeping temperatures at readings
near normal. Upper level high pressure quickly rebuilds across the
central and western ConUS, which will allow temperatures to
quickly warm. Most areas will see summertime temperatures back
into the 80s to 90s beginning on Sunday and lasting through the
middle of the week. Dry conditions are expected during this time.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Friday Morning)
Issued At 147 AM MDT Thu Aug 25 2016

Scattered showers and isolated thunderstorms will
increase in coverage through tonight, especially after 00Z. Local
MVFR conditions are possible near any of the showers or
thunderstorms. Otherwise VFR conditions will prevail.

&&

.UNR Watches/Warnings/Advisories...
SD...None.
WY...None.
&&

$$

SHORT TERM...Pojorlie
LONG TERM...MLS
AVIATION...MLS



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