420 
FXUS63 KUNR 111718
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1018 AM MST Fri Mar 11 2022

.UPDATE...
Issued at 800 AM MST Fri Mar 11 2022

14z surface analysis had weak low near KECS, which was under tight
800-600mb baroclinic zone. Narrow, shallow lift is generating
flurries/-sn from southeast MT to KRAP-KVTN. Expect activity to
continue through the morning hours with latest RAP/HRRR suggesting
lingering activity into the afternoon. 0.5km shows plenty of sun
either side of band. Forecast updated to account.

&&

.DISCUSSION...(Today Through Thursday)
Issued at 151 AM MST Fri Mar 11 2022

Western CONUS ridge will shift east this weekend, allowing for 
much milder air to push back into the region. Other than a few NW 
flow impulses, no major systems expected in the period. Cold front
and associated upper trough has pushed through the region. The 
core of the cold air will remain to the NE of the FA with highs 
today mainly in the 20s. Stalled baroclinic zone combined with 
steep ll lapses rates will support isolated snow showers through 
most of the day today in the SW third. Retained low pops for this.
Western ridge will shift east this weekend with WAA spreading 
into the region via breezy westerly winds. There are some 
indications that enough WAA upglide may develop late tonight into 
Sat morning ahead of the warm front to support some flurries or 
light snow across NE WY into NW SD. However, forecast models 
remain dry attm, just supporting increasing mid clouds. Hence, 
left any mention out for now. Weak northern tier clipper system 
will shift a sfc trough through the area Sat afternoon. The main 
impact from this system will be windy conds over NW SD where adv 
winds are expected, possibly low end warning levels in far NW SD 
if deeper mixing results. Westerly winds will allow most places to
warm into he 40s and 50s Sat and again Sunday ahead of the next 
impulse. The next low pressure system will arrive Sunday, 
supporting a cool front and light rain or snow showers late 
afternoon and evening. Best chance for precip will be over NE WY 
and the northern Black Hills where some light snow accums are 
possible Sunday night, generally an inch or less. Semi-zonal 
perturbed flow will set up for next week, with mainly mild temps 
and chances for showers with any passing impulse, the next of 
which looks to arrive Tues night into Wed. The warmest day next 
week looks to be Tues when a decent amount of warm air will spread
north ahead of the approaching low pressure system. Widespread 
60s and few 70s will be possible, all hinging on the speed of the 
trough and the amount of clouds.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Saturday)
Issued At 1018 AM MST Fri Mar 11 2022

VFR conditions are expected region wide through most of the TAF 
period. Some MVFR/IFR cigs may develop over the Black Hills early
Saturday morning around 14z to 16z. Breezy N/NW winds will 
develop this morning and persist into the afternoon. LLWS may
develop Saturday morning over NE WY, NW SD, and the Black Hills. 

&&

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

$$

Update...Helgeson
DISCUSSION...JC
AVIATION...Wong