101 
FXUS63 KUNR 111824
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1224 PM MDT Wed Oct 11 2017

.DISCUSSION...(Today Through Tuesday)
Issued at 347 AM MDT Wed Oct 11 2017

Upper level analysis has ridging over the central CONUS with a
strong trof entering the Pacific Northwest. Skies across the
northern Plains are mostly clear. At the surface, lee trof is
located across central Montana into northeast Wyoming with
temperatures at 4am mainly in the 40s. Winds are out of the south
at 5 to 15 mph.

Warmer air will continue to build into the area today, ahead of an 
approaching cold front. Highs today will be in the in the mid 60s
to mid 70s. Surface lee trof will produce breezy south-southwest 
winds in some areas today, especially across parts of northeast WY
and south central SD. A cold front will cross the area late 
tonight and Thursday morning, bringing much cooler air for the 
latter part of the week. After today, high temps will gradually 
cool into the 40s to around 50 degrees on Saturday.

Upper ridge slides east as active southwest upper flow takes 
over, and will bring increasing chances for showers by late 
Thursday night/Friday. The best chances for showers look to be on 
Saturday as the trof is progged to swing east across the region. 
Temps look cold enough during the overnight and early morning 
hours for some snow showers, especially on Saturday across the 
higher terrain. Some freezing precip may be possible across far 
northwest SD early Saturday morning.

Medium range models agree on a dry and warmer period for Sunday and 
especially early next week as a broad ridge is forecast to build 
across the western US and eventually into the Plains. 

&&

.AVIATION...(For the 18Z TAFS Through 18Z Thursday)
Issued At 1222 PM MDT Wed Oct 11 2017

VFR conditions will continue through the forecast period. Areas 
of low level wind shear are expected between 03Z and 09Z tonight 
across the western South Dakota plains.

&&

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

$$

DISCUSSION...15
AVIATION...13