083 
FXUS63 KABR 210538 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1238 AM CDT Sat Aug 21 2021

.UPDATE...
Issued at 840 PM CDT Fri Aug 20 2021

Updated pops and sky cover now that convection has moved east of
the CWA. Some lower clouds are forecast on the backside of the
system over ND. Otherwise forecast is doing well.  

UPDATE Issued at 400 PM CDT Fri Aug 20 2021

Severe Thunderstorm Watch 452 has been issued for Traverse and 
Big Stone Counties until 10 pm CDT. 

&&

.SHORT TERM...(This Evening through Saturday Night)
Issued at 202 PM CDT Fri Aug 20 2021

Heavy rain and strong storms remain the main concern today. As of 
shortly after 18Z, steady moderate rain has resulted in visibility 
falling to less than 2SM at times at MBG. While we will continue to 
monitor north central SD, the main focus will likely be east of a 
line from Aberdeen to Redfield. Thunderstorm activity will continue 
to increase, with an initial broken line of showers set up from 
Traverse County down through eastern Hamlin County. The main 
question is if and when additional storms will develop behind this 
line. Still expecting most of the thunderstorm activity to shift out 
of our west central MN counties by around 00Z along with the cold 
front. The surface low over eastern ND will quickly exit into Canada 
late this evening and overnight. Even after the precipitation, winds 
will remain breezy out of the west through the overnight hours for 
our area. 

Expect highs Saturday to top out in the 70s, or nearly 10 degrees 
below average for this time of year. The surface ridge will be set 
up over central SD by mid afternoon, and eastern SD/western MN by 
late afternoon. This feature will be short lived though as another 
surface low and 500mb trough organizes to our west. Central SD could 
get a few showers or thunderstorms to near overnight into Sunday 
morning.

.LONG TERM...(Sunday through Friday)
Issued at 202 PM CDT Fri Aug 20 2021

The 500mb low currently set up over southwestern British 
Columbia/northwestern WA state will become an open wave over ID 
Saturday night, and swiftly push across MT, and then the Dakotas 
during the daytime hours Sunday. Another round of strong to severe 
storms will be possible Sunday. At this point it looks like the main 
threat will again be over our central and eastern counties given the 
timing. As noted in the previous discussion, we will have a surge of 
low level moisture with dewpoints rising back into the 60s. It still 
likes the better instability will be to our south, which matches up 
pretty will with the thinking of where the slight risk is on the SPC 
day 3 convective outlook. While slight chance pops are possible for 
northern and northeastern SD Tuesday, the 500mb wave stays mainly 
over Canada and weak across our area. A better chance of 
precipitation returns for Thursday, but there is some consistency 
issues in the forecast solutions at this point. Will keep with a 
blended solution.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1238 AM CDT Sat Aug 21 2021

Terminals KABR,KATY,KPIR,KMBG

Mostly VFR conditions are expected through Saturday, although a few 
lower clouds are expected across northern South Dakota overnight. 
Gusty winds are also expected through Saturday morning.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&

$$

UPDATE...TDK
SHORT TERM...KF
LONG TERM...KF
AVIATION...Wise