Twin Brooks, South Dakota Weather Forecast Discussion

636
FXUS63 KABR 120837
AFDABR
Area Forecast Discussion
National Weather Service Aberdeen SD
337 AM CDT Fri Sep 12 2025
.KEY MESSAGES...
- There is a Marginal Risk (level 1 out of 5) of severe weather
  over the northwestern half of SD tonight and over central SD
  Saturday.
- High temperatures will run 5 to 10 degrees above normal through
  Tuesday, before returning to seasonal values.
&&
.DISCUSSION...
Issued at 336 AM CDT Fri Sep 12 2025
Smoke still lingers over our area, showing up in the HRRR/RRFS model
guidance. The EPA`s fire.airnow.gov site has shown PM2.5 aqi values
in the yellow category for most sensors near and east of the MO
River early this morning. The overall trend is for improved
conditions smoke wise. We will keep the mention of smoke out of the
forecast as it is not lowering visibility.
Taking a look at the 08Z surface map, the low pressure system
stretching from southwestern SD through central NE. Out ahead of the
low we have ongoing light showers and a few thunderstorms with winds
out of the southeast and dewpoints in the 60s. The main concern for
strong to severe storms remains to our north. Lapse rates remain
impressive, but shear is set up across ND. While we do have some
thunderstorms, they have been small and have had a difficult time
sustaining themselves. We`ll continue to monitor the trends as these
showers and storms move north-northeast around 25kts. One concern
noted by several CAMs was the potential for the thunderstorms
currently over northern ND (near Fort Totton/Devils Lake) to slide
southeast and clip our far northeastern counties. While the storms
are pushing out to the southeast, it`s unknown if they will be able
to make it to our far northeastern counties. Still, we have slight
chances (20%) of showers and storms lingering over our northeastern
counties until nearly 21Z, but this will continue to be fine-tuned
this morning. A warm layer above the surface will act to limit storm
development this afternoon. 700mb temperatures will be 11-12C.
The surface low will set up across mainly southwestern to south
central SD through western NE this afternoon and remain in place
through much of the day Saturday. The surface low will be reinforced
by an additional trough from the west-southwest, with a trough of
some sort set up across SD through at least Thursday morning. Low
chances for precipitation will continue, with the highest (30-
60%)being when 500mb troughs swing through Sunday and Tuesday night
into Thursday.
As for the near term, dewpoints will near 70F this afternoon with
temperatures topping out in the 80s, except in the low 90s over our
southwestern counties of central/south central SD. Another round of
storms is expected this evening west of the MO River, and overnight
across central SD with the chance of precipitation increasing to 40-
70% by around daybreak Saturday. There is a Marginal Risk of severe
storms over primarily the northwest half of SD on the Day 1 outlook
and over central SD for the Day 2 outlook for the potential for
these storms tonight into Saturday morning.
Confidence remains high in the temperature forecast through the
period, with highs mainly in the upper 70s and 80s through Tuesday
before a slight cool down with highs in the 70s Wednesday through
Friday (or near seasonal normal values).
Overall fire weather concerns remain limited, despite the limited
rain over the last couple of weeks and some drying of fine fuels
(grasses). This is due to the higher dewpoints and generally light
winds that are expected to continue through at least Saturday night.
Near surface winds increase Sunday into Monday, with gusts 25-30
mph.
&&
.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1131 PM CDT Thu Sep 11 2025
Terminals KABR,KATY,KPIR,KMBG
VFR conditions for all terminals with a southeast wind component.
LLWS possible for KABR/KATY for next few hours. Best chance for a
storm in near the KMBG terminal, but will wait as storms upstream
have been weakening as they move northeast towards the terminal.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
DISCUSSION...06
AVIATION...07

NWS ABR Office Area Forecast Discussion