387 
FXUS63 KUNR 132143
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
243 PM MST Fri Dec 13 2019

.DISCUSSION...(This Evening Through Friday)
Issued at 241 PM MST Fri Dec 13 2019

Upper trough is crossing the Mississippi Valley, with northwest flow 
across the northern Great Plains. A series of waves are crossing the 
region, especially west and south of the CWA associated with +150kt 
jet streak over the WY/CO Rockies. At the surface, a cold front is 
pushing through southeast MT and northwest SD. Temps are in the 30s 
across the CWA, but quickly dropping off into the 20s behind the 
front across far northwest SD. The front will continue southwestward 
until stalling around the Black Hills area through southwest SD. 
Lows tonight across northwest to central SD will dip into the teens 
and single digits. Across northeast WY through the Black Hills, lows 
will remain in the 20s. KUDX radar shows snow showers continuing 
mainly across the Black Hills area through southwest SD. Snow will 
continue over the next few hours with minimal additional 
accumulations, then diminish through the evening hours. Linger 
flurries will be possible overnight tonight. Areas of freezing fog
will also be possible overnight into Saturday morning, especially
across the upsloping eastern portions of the Black Hills. The 
next wave will bring good chances of light snow Saturday through 
Saturday night across northeast WY through southwest SD. 
Additional accumulations with this second round of snow will be 
light. Right now, it appears the highest accumulations will be 1-3
inches across southwest SD. Upper ridging will gradually build 
into the region early next week, bringing dry weather and warmer 
temperatures. It appears the warmest temps will be toward the 
later part of the week, with highs well into the 40s and possibly 
into the 50s.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Saturday)
Issued At 1028 AM MST Fri Dec 13 2019

Scattered snow showers over northeast Wyoming, the Black Hills,
and southwest South Dakota will result in areas of IFR visibility. 
Widespread MVFR/IFR ceilings will continue over northeast Wyoming 
and northwest South Dakota...with the low ceilings spreading 
southward this afternoon and evening. IFR/LIFR conditions with
stratus/freezing fog will be found around the Black Hills late 
this afternoon through tonight, including the KRAP terminal.

&&

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

$$

DISCUSSION...13
AVIATION...7