657
FXUS63 KABR 081934
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
234 PM CDT Wed Oct 8 2025

.KEY MESSAGES...

- Southerly winds today will gust to 30 to 45 mph, with strongest
winds west of the James River. Southerly winds will increase again
on Saturday with gusts up to 40 mph over the forecast area.

- Light rain this weekend, mainly for the James River Valley and
eastward. Probability of rainfall of a quarter of an inch or more
ranges from 25 to 50 percent.

&&

.DISCUSSION...
Issued at 220 PM CDT Wed Oct 8 2025

Strong southerly wind remains the main forecast concern this
afternoon. Low-level jet overhead has been able to mix 40 mile per
hour gusts to the surface this afternoon over parts of central South
Dakota. We continue to monitor observations, but at the time of this
writing (~18Z) there are no plans for a Wind Advisory, as both
forecasted and observed winds have fallen short of criteria thus
far. Elevated fire weather conditions are only a minor concern today
due to the southerly winds advecting increased moisture into the
region, but any fires that do manage to start could spread rapidly
due to the strong winds. These elevated winds are expected to
persist through the afternoon and evening (continuing to gust to 40
miles per hour) before decreasing slightly overnight due to the loss
of good mixing into the boundary layer. Winds rebound Thursday,
shifting to be mainly over northeastern South Dakota with the
progression of low-level jet. Gusts are expected to peak around 30-
35 miles per hour, but some downsloping due to the direction of flow
may be possible over the Prairie Coteau, leading to the potential
for a localized enhancement of winds. A dry cold front is expected
to move through the forecast area Thursday, which will push the low-
level jet fully into Minnesota and diminish surface winds by
Thursday evening.

An upper-level ridge will continue to be present over the central
CONUS for the next couple of days, with an upper-level trough to the
west set to replace it in a couple of days. This setup will allow
for a bit of a warmup Thursday with the warmer airmass being
advected in from the south. This will push temperatures into the mid-
70s, about 10 degrees above normal for this time of year. With the
passage of the dry cold front, temperatures will decrease slightly,
with dew points following suit. Resulting afternoon highs and
overnight lows will be near-normal to just above normal, in the
upper 60s and 40s to low 50s respectively through Saturday.
Overnight temperatures specifically look to stay warm enough through
the weekend to where frost formation will likely not be a concern.

The upper-level trough will support the development of a surface low
pressure center that will drag a front across the forecast area this
weekend. The main forcing mechanism will be a low-level jet of
around 50 knots moving overhead, producing some light rain showers.
At this point model soundings do not look very conducive to deep
convection, with lapse rates generally around 6-6.5 C/km or lower
limiting MUCAPE. As a result, rain rates are expected to be low. The
latest NBM runs show a broad 25-50% chance of 0.25" of accumulation
over 48 hours ending early Monday morning, with chances increasing
as moving from southwest to northeast. Probability of 0.5" peaks at
just over 30%, again over northeastern South Dakota into western
Minnesota.

Perhaps of greater concern this weekend is the return of strong
southerly winds ahead of the front. Pressure gradient will tighten
as the low develops to the west, creating the aforementioned low-
level jet, subsequently supporting stronger gusts mixing to the
surface Saturday and Sunday afternoon. At this time, winds are
forecast to remain below Wind Advisory levels (sustained winds of 30
miles per hour or gusts to 45 miles per hour), but it is not out of
the question to see gusts reach that high. NBM gives pockets of 10-
20% chances for either sustained winds or wind gusts to reach
criteria, mainly over central and north central South Dakota. These
southerly winds will be advecting moisture into the the region as
well, and dew points will reach 50+ degrees on Saturday over central
and north central South Dakota before expanding to cover the entire
forecast area Sunday. This added moisture will help keep humidity
plenty high enough to where Red Flag conditions will most likely not
be much of a concern. Winds are expected to diminish and turn
northwesterly with the passage of the front Sunday.


&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1202 PM CDT Wed Oct 8 2025

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are expected through the TAF period, and skies will
remain mostly clear until some high to mid clouds move in Thursday.
The bigger aviation concern is the strong southerly winds and wind
gusts over the forecast area through most of the period. Peak winds
will be this afternoon over central and north central South Dakota,
where sustained winds may reach 25 knots gusting to 35 knots. Areas
further east will still see gusts of 20 to 30 knots through the rest
of the afternoon. Winds will decrease slightly overnight tonight due
to the lack of good mixing, before rebounding in strength over
northeastern South Dakota tomorrow afternoon. Due to this decrease,
pockets of low-level wind shear may emerge. This will mainly occur
over northeastern South Dakota into western Minnesota where the low-
level jet is located, but it will depend a bit on just how low
surface winds get. Confidence is low enough on timing and location
to exclude any mention from the TAFs, but it will be a possibility
overnight. Winds will diminish and veer northwesterly Thursday with
the passage of a dry cold front through the afternoon and evening.


&&

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

$$

DISCUSSION...BC
AVIATION...BC