289
FXUS63 KABR 311125
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
525 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.

&&

.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 /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 522 AM CST Sat Jan 31 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions with a trend towards MVFR and possibly IFR
VISBY/CIGS as snow moves into each terminal. As the system
departs, could be a brief period of mixed precipitation.

&&

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

     Wind Advisory from 2 PM this afternoon to 9 PM CST this evening
     for SDZ007-008-021-023.

     Winter Weather Advisory from 11 AM CST /10 AM MST/ this morning
     to 5 PM CST /4 PM MST/ this afternoon for SDZ033>035-045-
     048.

MN...None.
&&

$$

SHORT TERM...07
LONG TERM...06
AVIATION...07