815 
FXUS63 KUNR 032327
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
427 PM MST Sun Nov 3 2019

.DISCUSSION...(This Evening Through Sunday)
Issued at 157 PM MST Sun Nov 3 2019

Current surface map has an area of low pressure over northeastern
North Dakota, with a cold front extending westward into northern 
Montana. Aloft, there is a ridge over the eastern Pacific with a 
trough over the Ohio River Valley associated with a Hudson Bay 
low. These two upper level features result in northwest flow over 
the northern High Plains. Water vapor imagery shows a shortwave 
over south central Montana/northwestern Wyoming. Radar imagery
has isolated showers across much of the forecast area.

For tonight, cold front drops through the forecast area, as the 
wave passes over northeastern Wyoming, the Black Hills and 
southwestern South Dakota. Will see some light snow, with 
favorable upslope enhancement over the northern Black Hills. 
Overall, amounts will be light, with only a few inches expected. 

Northwest flow aloft continues through the week as the low level 
baroclinic zone impacts the forecast area. On Monday, surface high 
settles in across the Dakotas, keeping the cooler airmass in place. 
On Tuesday, the front lifts north as a weak clipper system moves 
into eastern Montana/western North Dakota. Cold air surges back 
southward Tuesday night, as 1040 mb high drops into the Dakotas on 
Wednesday, leading to cold and brisk conditions. As the high shifts 
east Thursday, low level warm advection allows for some gradual 
warming. On Friday, warm and dry air is in place, making it the best 
day of the week. The warm conditions continue into early Saturday, 
but then models indicate another clipper and cold front dropping 
into the area Sunday. The timing of this system is very uncertain, 
but expect another shot of cold air and chances for snow for the 
first half of next week. 

&&

.AVIATION...(For the 00Z TAFS Through 00Z Monday Evening)
Issued At 422 PM MST Sun Nov 3 2019

Rain and snow showers will continue will decrease early this
evening, but linger through the overnight hours across the area.
MFVR/IFR conditions are expected, especially from northeast
Wyoming through the northern Black Hills. Some improvement will be
possible tomorrow morning across these areas, but should still 
remain mostly within the MVFR category.

&&

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

$$

DISCUSSION...MLS
AVIATION...13