399 
FXUS63 KUNR 221133
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
433 AM MST Tue Jan 22 2019

.UPDATE...
Issued at 401 AM MST Tue Jan 22 2019

Remaining headlines have been dropped as conditions continue to
improve.

&&

.DISCUSSION...(Today Through Monday)
Issued at 235 AM MST Tue Jan 22 2019

Current surface map places low over eastern Colorado with inverted
trof into central South Dakota. Upper trof crossing the central
Rockies, with best Q-G forcing south of the forecast area. As a
result, radar trends show decreasing coverage of snow over the 
forecast area. Winds also decreasing as the best pressure rises 
shift south of the area. With improving conditions, have dropped 
some of the warning/advisory area...with remaining areas probably
cancelled in the next few hours. 

Northwest flow sets up across the area for the last half of the
week into early next week with amplification of west coast ridge 
and Hudson Bay low. Several clipper systems will swing through the
Canadian Rockies into the Great Lakes region. Temperatures will 
oscillate with each system; brief warm up ahead of each clipper 
followed by surge of arctic air. Each arctic front will result in 
some widespread light snow across the area along with breezy 
northwest winds. Low confidence in temperature forecast, 
especially for the weekend into early next week. Timing of arctic 
fronts will have a big impact on daily temperatures...a difference
of just a few hours can mean the difference between 20s and 40s
for highs.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Wednesday Morning)
Issued At 433 AM MST Tue Jan 22 2019

Lingering areas of light snow will end across southern South 
Dakota early this morning. MVFR/IFR conditions will persist across
much of the area through late morning, with improving conditions 
this afternoon. Northwest winds of 15 to 30 mph, with higher gusts
this morning, will gradually decrease in the afternoon. 

&&

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

$$

Update...7
DISCUSSION...7
AVIATION...26