508
FXUS63 KABR 061129 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
629 AM CDT Thu Aug 6 2026

.KEY MESSAGES...

- High temperatures will be around to slightly above average
  today, cooling to slightly below average on Friday.
  Temperatures will steadily warm back up through the weekend
  before cooling back down early next week.

- There are a few windows of opportunity for night-time showers
  and thunderstorms later this week, primarily this evening
  through Friday morning and again late Friday night into
  Saturday afternoon over portions of south central and
  northeastern SD through western MN. Right now, the best chance
  for widespread rainfall (30-60% chance) is lining up for
  Sunday evening through Monday morning.

- There is a Marginal Risk (level 1 of 5) for isolated severe
  storms this evening over the southern half of Jones and Lyman
  Counties. The main threats will be 1 inch in diameter hail
  and wind gusts of 60 mph.

&&

.UPDATE...
Issued at 626 AM CDT Thu Aug 6 2026

Aviation discussion updated below for the 12Z TAFs.

&&

.DISCUSSION...
Issued at 132 AM CDT Thu Aug 6 2026

There will be south southwesterly winds at the surface through the day
today. This morning these winds will help to create some downsloping
winds along the eastern side of the Prairie Coteau, along I-29. The
downsloping winds will be gusty at time, with gusts up to 30 mph
possible through the morning  into the afternoon as well as
overnight into Friday morning. The southerly winds will also help to
bring warmer temperatures in today. Highs will be in the low 80s to
upper 90s, warmest in areas west of the Missouri River. North
central SD will also see drier conditions today, with relative
humidity values below 20% in areas. Afternoon winds will be gusting
below 20 mph, which helps to reduce fire weather concerns slightly,
though there is still High Grassland Fire Danger Index values over
Corson county from the dry conditions. The southerly winds will also
be pushing the near surface smoke out this morning, though there
will continue to be smoke aloft today that will cause some hazy
skies at times.

The upper-levels of the atmosphere have northwest flow over SD
through the weekend and into next week. Occasionally, the models
hint at a shortwave moving along that flow over SD, which would help
to support surface boundaries moving over the state and potentially
shower and storm development. One of these shortwaves is forecast to
move over central and northeastern SD at some point late this
afternoon into tonight. The warm temperatures will help to provide
some instability today in front of the surface trough that will
provide lift for storm development. Additionally, the development of
a low level jet during the evening and overnight will help to
support storms or develop storms over south central and northeastern
SD. The big question is, will there be enough moisture for shower
and storm development. Some models have a sliver of moisture moving
into central and northeastern SD along the southerly winds in front
of the boundary, while other models do not. The models that have the
moisture have storms developing at some point during the late
afternoon into early Friday morning. There are low confidence for
anything to develop because of the lack of moisture, but if there is
enough moisture, something could always pop up. In fact, there is a
sliver of a marginal risk (level 1 of 5) that IF any storms do
develop over portions of south central SD, then they could become
severe. The lapse rates and shear over that area suggest that storms
could have hail up to 1 inch and wind gusts of 60 mph.

Multiple upper-level shortwave and surface boundaries are forecast
to move over SD into and through the weekend. These continue
bringing a small chance for showers and storms to develop, such as
at some point between Friday night into Saturday afternoon. However,
it always comes back to if there will be enough moisture to support
the development of anything. This causes low confidence and lower
chances for showers and storms. The next big chance for showers and
storms will be Sunday evening into Monday morning, with 30-60%
chance. There is still a bit of variation in the models as to the
location and timing of these showers and storms, as some models have
the storms developing to the east of the area and some develop
storms over SD. This will need to be watched a bit more in upcoming
model runs to get more details on what will be happening.

Temperatures will be cooling slightly Friday, with highs in the
upper 70s to upper 80s, before warming up again during the weekend
with highs in the 80s to 90s. The northerly winds Friday will help
to push higher concentrations of wildfire smoke in over SD. Though
with very little mixing occurring, that smoke will be staying aloft
and create more widespread hazy skies.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 626 AM CDT Thu Aug 6 2026

Terminals KABR,KATY,KPIR,KMBG

Low-level wind shear (LLWS) may be lingering across parts of
the region early this morning. Otherwise, VFR conditions are
forecast through the TAF period. There remains a very small
chance (~10%) for a stray -TSRA near the KATY region this
evening, but with confidence so low, will leave out mention at
this time.

&&

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

&&

$$

UPDATE...TMT
DISCUSSION...12
AVIATION...TMT