128 
FXUS63 KUNR 211127
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
527 AM MDT Sun May 21 2017

.DISCUSSION...(Today Through Saturday)
Issued at 251 AM MDT Sun May 21 2017

Low pressure system currently over southwestern Minnesota early
this morning will move into northeastern Minnesota this afternoon.
Disturbances rotating southward on the west side of the upper low
will be accompanied by weak CAA aloft. SFC heating will push the
MUCAPE to 500-900J/KG this afternoon. Moisture is relatively
limited with the northwesterly flow, however expect to see
scattered showers today with a few thunderstorms this afternoon. 
Highs this afternoon are expected to mainly be in the 60s on the
plains with 50s in the Black Hills. A stronger impulse will 
affect the area tonight and Monday bringing a better chance of 
showers and thunderstorms Monday into Monday evening. Monday will 
be windy an cooler with highs mainly in the lower 50s to lower 
60s.

The upper low will finally move off to the southeast by mid week 
with a transient ridge crossing the forecast area on
Wednesday/Wednesday night. This will bring much warmer weather 
and dry conds to the region for a couple days. Another upper
trough will drop southward out of the Canadian prairie provinces
on Thursday, with precipitation chances and slightly cooler
temperatures returning for the weekend. Moisture looks to be 
limited with this next round of troughing given closed GOMEX and 
PAC origin flow.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Monday Morning)
Issued At 526 AM MDT Sun May 21 2017

VFR conditions expected through Monday morning. Isolated afternoon
and early evening thunderstorms will be possible across the entire
area.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&

$$

DISCUSSION...10
AVIATION...15