080
FXUS63 KABR 311744 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1144 AM CST Sat Jan 31 2026

.KEY MESSAGES...

- Sisseton hills downslope winds expected later this afternoon
  through the evening. Winds to peak in excess of 50 mph. Snow
  moving in during the evening could result in intermittent and
  significant reductions in visibility.

- Snow moving across the state today to accumulate around an inch
  or two. As the system moves east, west river through the
  Missouri valley may get a light glaze of ice.

- Near to above normal temperatures are forecast for much of the
  7-day forecast.

&&

.UPDATE...
Issued at 1138 AM CST Sat Jan 31 2026

Aviation discussion updated below for the 18Z TAFs.

UPDATE Issued at 1018 AM CST Sat Jan 31 2026

As of 1030am, radar and webcams show a north to south oriented
line of snow, associated with the warm front, falling around and
along the Missouri River. Per reports and webcams over western
Corson and southward to Stanley Counties there is light freezing
rain mixed in with the snow. As the front continues to track east,
this line of snow will continue to track into northeastern
SD/western MN this afternoon and continuing through the overnight.
There is the ongoing potential for light freezing rain/drizzle
mixed in at times over central SD this afternoon and evening,
along and behind the warm front with a glaze of ice possible. The
threat for freezing rain/drizzle this evening and late tonight is
possible James Valley and eastward but very low confidence as it
all depends on 850mb temps (hovering right at or above 0) and low
level saturation/lift as we lose ice nucleation aloft behind the
main snow line. With the falling snow over the Coteau and strong
southwesterly winds at the surface, drifting and blowing snow is
possible along the eastern slopes of the Sisseton Hills as wind
gusts up to 50 mph is possible, which could drop visibilities to a
half mile or less at times.

&&

.SHORT TERM /TODAY THROUGH SATURDAY/...
Issued at 156 AM CST Sat Jan 31 2026

Overall not much change in the assessment of the trough moving
through with some light snow followed by a transition to a mix.
Winds also stay about the same, with a stiff south breeze and
Sisseton hills downslope winds.

With regards to the downslope timeframe/intensity, NAM BUFKIT
profiles begin to indicate downslope begins around 18Z with a peak in
the critical layer of 50kts around 00Z. That is about when snow sets
in for the Sisseton point. So, thus there is a short window in which
the downslope winds phase with snow around 00-03Z with the winds
dropping thereafter. Thus not overly concerned for impacts as
existing snow cover in the area has been shown to not really matter
as we`ve had a previous downslope a week ago that registered a 67
mph gust and not really anything on the webcam.

Will leave the winter weather headlines in place for now as well, as
there is probabilistic information to support a light glaze of ice.
A deeper look into the BUFKIT profiles however suggest the evidence
is less clear. As the bulk of the precipitation (snow) moves east,
we are left with some residual moisture and ascent. In phase with
the loss of ice and lift, we see just a sliver of the warmest
portion of the inversion work its way above freezing. NAM BUFKIT
profiles suggest a layer of approximately 500 feet. Below this is
also a deep cold layer to the surface. The HRRR and RRFS also
suggest more dry air working into the profile which would cut off
precipitation entirely, and that is probably more appropriate as
winds shift to southwest and then northwest.

So continuing the winter weather headlines, though with significant
reservations such as: are we actually seeing precipitation as
profiles warm? Is the layer thick enough for melting? Is the sub-
freezing layer that follows thick enough for re-freeze. Is there too
much dry air in the profile. The latest HREF is only generating
about 0.01 to 0.02 inches of ice, and less than a 30-50% probability
of exceeding that limited to Dewey/Jones/Stanley and points west.
And the biggest question is, what impact will this even have if its
falling on a 1/2" to 1" of fresh snow?

And as for snowfall, again not much change with just a slight re-
arrangement of totals here and there. Overall HREF and NBM both point
to about 1".

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Issued at 156 AM CST Sat Jan 31 2026

At 00Z Monday the surface weather map will have high pressure over
central Canada, with a ridge extending south across the eastern
Dakotas, with the exiting low over Ontario with the cold front
draped well to our south. The coldest air at 850mb will have
already shifting to our east. Still, we`ll remain under a pattern
with the coldest air with 850mb temperatures of -5 to -9C remaining
over northeastern SD and west central MN through Tuesday morning.
This cooler airmass will move over the entire forecast area during
the day Tuesday as the Canadian high moves over northeastern SD and
MN.

The main 500mb trough moving through the northwesterly flow will be
over MT early Monday morning, and continue across the Dakotas later
Monday into early Tuesday, with additional weaker waves lingering
over the area through Tuesday night. The result will be plenty of
clouds, along with a 20-40% chance of light snow late Monday
afternoon through Tuesday. Precipitation looks limited, but with
snow to liquid ratios of 10-15:1, a quick dusting to around a half
an inch of snow is not out of the question. The probability of 1" or
more snow is 20% or less, maxing out over the James River Valley at
this time.

The rest of the forecast period, through the start of next weekend,
looks mainly dry. However, we will be watching the evolution of the
surface low Thursday over south central SD that will push a warm
front across the Dakotas and MN and bring the warmest air of the
week with highs topping out in the upper 30s east of the James River
to the 40s and even 50s elsewhere (highest over south central SD).
Given the deviation from what has occurred temperature wise over the
past few weeks, the temperature forecast for Friday and Saturday may
end up being warmer (by around 5 degrees or so) than the current NBM
forecast of 20s to low 40s. We`ll continue to monitor the trends for
the end of the week through early next week as a warmer pattern
takes hold.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1138 AM CST Sat Jan 31 2026

Terminals KABR,KATY,KPIR,KMBG

MVFR/IFR CIGs and VSBY in -SN/SN this afternoon and evening from
west to east across the region as a band of precipitation moves
through. There is small potential (~30%) of -FZRA mixing in on
the backside of the precipitation as it moves eastward. Low-level
wind shear (LLWS) will also be a concern across the region during
the TAF period this evening/overnight and have inserted mention
of this as well.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory until 5 PM CST /4 PM MST/ this afternoon
     for SDZ003-004-009-015-016-033>035-045-048.

     Wind Advisory until 9 PM CST this evening for SDZ007-008-021-023.

MN...None.
&&

$$

UPDATE...TMT
SHORT TERM...07
LONG TERM...06
AVIATION...TMT