Area Forecast Discussion
Issued by NWS Rapid City, SD

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000
FXUS63 KUNR 290959
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
359 AM MDT MON AUG 29 2016

.SHORT TERM...(Today Through Tuesday Night)
Issued at 358 AM MDT Mon Aug 29 2016

Weak but broad ridging continues across the region this
morning...with very weak upper level flow across the nrn plains as
the main flow stays well north across Canada. At the
surface...strong high pressure sits across Saskatchewan into ern
MT/wrn ND behind a cold front which has pushed across ne to sw SD in
the last few hours. This will bring cooler temps to nw SD into the
BH area today with highs in the mid 80s. Otherwise temps will be
back in the 90s across scntrl SD where the front will stall...though
5 degrees or so cooler than yesterday. Some storms may develop this
afternoon as the cap weakens along the BH convergence zone. With low
level flow actually becoming more NE today as the surface highs
pushes eastward...could see some of these storms actually move
westward into the ne WY plains. Along the stalled frontal boundary a
few storms are progged to develop this afternoon before dissipating
by late aftn or early evng. A few strong storms can`t be ruled out
given the SB Cape of 1500-2000 J/kg...but with shear very weak these
storms will likely be very pulsy. Tonight is expected to be quiet
with lows in the mid 50s to mid 60s. Upper ridging will strengthen
across the central CONUS Tuesday. This will continue to bring
generally dry weather to the area. The only exception could be
in the afternoon again across the BH as the cap weakens. SB Cape
will be weaker than today with very little shear so severe storms
are not expected. Highs will be in the 80s.

.LONG TERM...(Wednesday Through Sunday)
Issued at 358 AM MDT Mon Aug 29 2016

An upper level ridge will dominate the weather Wednesday and
Thursday with very low chances for precipitation as well as toasty
temperatures. Breezy to windy south to southeast winds are
expected given pressure gradient, which should keep minimum
relative humidities from falling off the table given moist
easterly component, especially on the SD plains. Southwest flow
develops Friday and gradually becomes westerly for the Labor Day
weekend. The result will be a slow decline in temperatures for the
weekend as well as better chances for showers and thunderstorms.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Tuesday Morning)
Issued At 358 AM MDT Mon Aug 29 2016

A boundary will shift slowly south this morning and stall for
this afternoon. Isolated thunderstorms may develop along the
boundary as well as over the higher terrain of the Black Hills.
Otherwise, VFR conditions are expected through tonight.

&&

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

$$

SHORT TERM...13
LONG TERM...Helgeson
AVIATION...Helgeson



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