080
FXUS63 KABR 101921
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
221 PM CDT Fri Oct 10 2025

.KEY MESSAGES...

- Light rain this weekend, mainly for the James River Valley and
eastward on Sunday. Probability of rainfall of a half of an inch or
more ranges from 30 to 50 percent for this area, highest along and
east of the Sisseton Hills.

- Winds will increase out of the southeast Saturday with gusts of 30
to 40 mph expected through Sunday before diminishing Sunday night.
Strongest gusts are expected along and west of the Missouri River
both days.

&&

.DISCUSSION...
Issued at 220 PM CDT Fri Oct 10 2025

High pressure center continues to build into the region this
afternoon, keeping skies clear and winds fairly light. Dry
conditions are expected through this evening. Temperatures will be a
bit above normal (upper 60s to low 70s for highs) through the
weekend before a cooldown to start next week.

The main focus of today`s forecast is the wind threat this weekend.
Another low-level jet will move into the forecast area beginning
overnight tonight and fully settling into place Saturday into early
Sunday. While the jet itself will reach up to 50 knots, cooler air
near the surface will prevent a well-mixed boundary layer from
taking shape, potentially limiting the strength of the gusts that
mix to the surface. Still expecting at least 30 to 40 mile per hour
gusts across the forecast area however, with the strongest being
over central South Dakota. The latest NBM resolves pockets of 10-20%
chances for wind gusts to reach Wind Advisory criteria of 45 miles
per hour, and up to 40% for sustained winds to meet the criteria of
30 miles per hour. There is not enough confidence or areal coverage
at this point to warrant a Wind Advisory for Saturday, but will
certainly be keeping an eye on trends. The jet progresses eastward
Sunday leading to similar strength gusts over northeastern South
Dakota and west central Minnesota Sunday afternoon, but another
mechanism will follow shortly behind the departing jet over central
South Dakota. As the surface low pressure center to the north
progresses, the pressure gradient on the back end will tighten,
transitioning central and north central South Dakota to strong
northwesterly flow. Gusts upwards of 40 miles per hour will be
possible, and forecast sustained winds are just shy of 30 miles per
hour, near the Wind Advisory threshold. NBM probabilities reflect
this, resolving a broader area of 30-50% chances for either
sustained winds or wind gusts to hit Wind Advisory criteria. Areas
with the strongest gusts will mainly be west of the Missouri River
Sunday, but 35+ mile per hour winds are still anticipated over the
entire forecast area.

Despite the strong winds this weekend, fire weather is not
anticipated to be a large concern. Moisture advection into the
region from the southerly winds in addition to the chances for
showers means that minimum afternoon humidity will stay above 40
percent both days this weekend, preventing any Red Flag conditions.
However should any fires start, they may spread rapidly due to the
strong winds.

Not much has changed in terms of the rainfall expectations this
weekend. As the low-level jet moves over the region, the divergence
will support the initially development of rain showers. However
further lift will be difficult for developing showers to come by, as
CAPE appears limited in the model soundings. Still, a stray rumble
of thunder is possible, but mostly expecting stratiform rain
showers. Still observing a somewhat large 25th/75th ensemble spread
(ranging between around 0"-1" in 24 accumulation ending 00Z Monday)
over northeastern South Dakota, where the rainfall is expected to be
the heaviest. Expectation remains closer the the median of around
0.3"-0.4" in total accumulation over that area. However should
embedded thunderstorms come to fruition, precipitation efficiency
could increase and some of those totals closer to 1" are not out of
the question.

With a high pressure center building in behind the low, winds will
weaken, but remain out of the northwest, continuing to advect cold
air into the forecast area. With this added cold air, overnight lows
early Monday morning may reach freezing over north central South
Dakota. Tuesday morning boasts a similar potential despite a
slightly different setup due to the high building in further and
weaker winds when compared to Monday morning. Ensemble probabilities
to reach freezing range from 40-60% over far north central South
Dakota Monday morning, with similar chances Tuesday morning over far
north central and far northeastern South Dakota. At the moment winds
appear to be too strong to support frost development (especially
Monday morning) but will keep an eye on trends and the potential for
a Frost/Freeze headline for Monday and Tuesday mornings.

Looking ahead a bit, the next chances for rain come during the
middle of next week. While there is still some disagreement with the
setup, some models resolve a trough over the western CONUS
developing a low pressure center over the Colorado area before
ejecting it into the Northern Plains. The setup of depth of the
upper level trough will be the main factor in where the surface low
ends up. An analysis of ensemble clusters gives roughly a 55% chance
for a setup conducive to possible precipitation over the region,
with a 25% chance of the most favorable setup to occur. While
rainfall is the expected precip type should this system manifest,
some models show some weak signal for snowfall accumulations in the
overnight hours, albeit mainly into North Dakota as opposed to South
Dakota. Still, some small chances to see our first winter
precipitation of the year, but temperatures would need to get below
the 10th percentile overnight. With an expected cloud deck overhead
in this scenario, reaching temperatures below freezing near the
surface appears very unlikely, and the ABR forecast area likely
remains safe from the onset of winter for the moment.


&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1203 PM CDT Fri Oct 10 2025

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are expected today and through the overnight hours as
a high pressure center builds into the area. The main aviation
concern comes at the end of the period, in which a low-level jet of
40-50 knots moves overhead. Gusty winds near the surface will begin
to increase tonight, before peaking Saturday morning and afternoon.
Gusts near the surface may reach up to 35 knots by the end of the
TAF period. This low-level jet will also produce some low-level wind
shear over central South Dakota overnight, and has been indicated in
the KPIR and KMBG TAFs at this time. The jet may also support some
light rain showers, but rainfall rates are expected to be low.
Still, the heaviest showers could drop ceilings to MVFR status, and
both the chance for showers and the drop in ceilings has been put
into a PROB30 group where appropriate. Thunder is not out of the
question, but confidence is very low, and any rumbles of thunder
that do emerge will be isolated.


&&

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

$$

DISCUSSION...BC
AVIATION...BC