912 
FXUS63 KUNR 160515
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1015 PM MST Fri Nov 15 2019

.DISCUSSION...(This Evening Through Friday)
Issued at 102 PM MST Fri Nov 15 2019

Progressive mild Pac flow will continue over most of the region 
with occasional impulses at times. Warm and dry westerly flow 
supporting a very mild fall day today, with many places seeing 50s
and 60s for temps. Clouds will increase as a clipper system 
approaches the FA tonight. Cool and moist easterly flow across NW 
SD may support some low clouds and/or patchy fog there, but the 
extent of this looks much more limited than yesterday and freezing
drizzle is not expected. Rain and some snow will develop with the
this system by Sat morning, with the best chances over NE WY and 
Black Hills. Not much if any snow accums expected given warm 
profiles with a half inch of less possible in the Black Hills. 
Gusty NW winds will develop Sat with semi-mild temps most places. 
Near wind adv winds will be possible over NW SD to east of the 
Black Hills, but given marginal numbers, will defer any wind adv 
issuance. 

Mean western NOAM ridging will then persist through early next 
week with any deeper ridge dampening troughs likely becoming split
given the position of the ridge per Aleutian Low location and 
lack of appreciable cold air over central Canada. Although 
forecast models show some potential for a stronger system in the 
central plains by Wed-Thur next week, as an upper impulse ejects 
from the expected SW CONUS closed low. Split flow pattern with an 
active northern stream would tend to bias this system south and 
east of the region, which is the current trend. This system will 
also bring a brief cool down Wed-Thurs of next week after which 
mild NW flow will become established again.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Saturday Night)
Issued At 1012 PM MST Fri Nov 15 2019

VFR conditions are expected through the overnight hours. Some 
patchy valley fog will be possible after midnight to the north 
and east of the Black Hills. A cold front will move through the 
area after 11Z, bringing MVFR to local IFR conditions in rain 
showers and high elevation snow showers to northeastern WY and 
southwestern SD including the Black Hills. Northwest winds will 
increase behind the front, gusting to over 30 kts across the 
northwest into west central SD plains through Saturday afternoon. 
VFR conditions return from north to south late Saturday afternoon 
across northeast WY and the Black Hills area. Some MVFR ceilings 
with light rain will be possible east of the Black Hills late 
Saturday morning through Saturday afternoon. 

&&

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

$$

DISCUSSION...JC
AVIATION...15