046 
FXUS63 KUNR 212322
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
522 PM MDT Sat Aug 21 2021

.DISCUSSION...(This Evening Through Saturday)
Issued at 155 PM MDT Sat Aug 21 2021

Current surface and satellite analysis shows surface high pressure 
situated over central NE while a surface low sits over western MT. 
Shortwave energy situated over Wyoming is expected to push northeast 
through the region later tonight into Sunday. CAPE values appear to 
be low this evening, however enough to help generate some isolated 
to scattered storms.  As daytime energy subsides, LLJ situated over 
the area should help with potential elevated overnight storms 
pushing northeast into ND by late Sunday morning. 

Following shortwave passage, dry and warmer conditions are expected 
the remainder of Sunday through most of Tuesday as the next upper 
trough approaches the region. With warming temperatures and breezy 
post frontal winds, expect elevated fire conditions for 
Sunday/Monday. Not going with a headline for now, but with enough 
mixing we could see near red flag conditions for Monday. The next 
cold front pushes through the forecast area later Tuesday through 
Thursday.  Ensembles differ on timing and placement of potential 
precipitation, so will have to monitor as we get closer to mid-
week.

&&

.AVIATION...(For the 00Z TAFS Through 00Z Sunday Evening)
Issued At 521 PM MDT Sat Aug 21 2021

Mostly VFR conditions expected through the period. Scattered high
based -shra/ts will spread into NE WY and western SD in the 
evening and overnight. Local MVFR conditions may occur with the 
strongest storms. LLWS is likely east of the Black Hills tonight 
due to a 50kt southerly low level jet. Breezy westerly winds will
persist Sunday.

&&

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

$$

DISCUSSION...Dye
AVIATION...JC