342 
FXUS63 KABR 081159 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
659 AM CDT Fri Oct 8 2021

.SHORT TERM...(Today through Saturday Afternoon)
Issued at 350 AM CDT Fri Oct 8 2021

A ribbon of weak mid-level instability is roaming eastward over the 
James River valley early this morning, and has been bringing a few 
sprinkles to the area over the past couple hours. At the surface, 
low pressure/surface trough is located over central SD. The surface 
boundary will slowly move east today, but do not expect much at all 
in the way of shower/thunderstorm activity as we'll have to await 
better shortwave energy later tonight and through the day Saturday. 
Any POPs today are mainly slight/low chance and confined to the 
northern CWA on the cool side of the boundary.

Expecting more widespread coverage of showers and storms during the 
day Saturday as the potent shortwave moves into the region. Surface 
low will deepen a bit over the region, with the low pressure system 
and surface boundary moving eastward through the CWA. Things are 
shaping up for potential strong to severe storms over the eastern 
CWA by Saturday afternoon. Steepening mid-level lapse rates will be 
in place over the area with a weakening cap by later in the 
afternoon. Modest instability is expected over the area, as surface 
dewpoints look to rise to around 60 degrees. Shear values should 
support organized storm structures capable of large hail over 
eastern portions of the CWA. CAM solutions do show scattered 
convection by mid to late afternoon from the James River and points 
eastward.

.LONG TERM...(Saturday Evening through Thursday)
Issued at 350 AM CDT Fri Oct 8 2021

A pretty active period is expected for the long term. Starting off 
with Saturday night, showers and thunderstorms are expected as upper 
low move across the region. Deep layer and low level shear are 
expected to be moderate to high, especially over the Coteau east 
into western MN. MUCAPES toward evening should be around 
500-1000 j/kg. Thus, with those ingredients in place, could 
certainly see a couple supercells form over the region from late 
afternoon into early evening. Later Saturday night into Sunday will 
bring some additional rain as upper system gradually shears across 
the region with deformation zone scraping mainly the northern parts 
of the CWA. Sunday night through most of Tuesday should prove mainly 
dry as a s/w ridge builds across the region ahead of the next major 
system.

The next system is still handled a bit differently by the major 
deterministic models. That said timing is similar, but the track of 
the mid-level low is somewhat different, with the GEM being furthest 
west, GFS furthest east, and the ECMWF in between. The GFS solution 
would bring the most pcpn to the region given the initial surge of 
WAA pcpn, and then a trowal/deformation zone over the western CWA. 
On the other hand, the GEM/ECMWF swing the WAA band through, then we 
pretty much get dry slotted. So, some pretty major differences can 
be seen. EPS progs overall seem to support deterministic ECMWF, 
while GEFS QPF plumes remain widely variable, suggesting low 
confidence in any one solution. Hopefully the models will converge a 
bit more as we get closer to the early part of next week. High 
temperatures should average out near normal for most of the 
forecast, but with all the clouds and pcpn, overnight lows may end 
up a bit above normal.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 658 AM CDT Fri Oct 8 2021

Terminals KABR,KATY,KPIR,KMBG

After the patchy morning fog and low clouds burn off, the rest of
the day should feature VFR skies/vsbys. 

&&

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

$$

SHORT TERM...TMT
LONG TERM...TDK
AVIATION...TDK