942
FXUS63 KABR 261937
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
137 PM CST Wed Nov 26 2025

.KEY MESSAGES...

- Below normal temperatures will continue through the beginning of
  December. Below zero wind chills area possible over northern SD
  each morning Thursday through Sunday. Wind chills will fall into
  the teens to near 20 below zero Sunday, Monday and Tuesday
  mornings.

- Snow will return Friday into Saturday morning. Currently, there
  is a 20-60 percent chance of receiving more than 3 inches of
  snow throughout the Missouri River valley region, and a 30-60
  percent chance of receiving more than 5 inches of snow across
  northeast and east central South Dakota with this upcoming snow
  event.

&&

.DISCUSSION...
Issued at 134 PM CST Wed Nov 26 2025

As of 1 PM CST, skies are a mix of sun (sunny across and west of the
James River valley) and clouds (cloudy on the Prairie Coteau over
into west central Minnesota). Temperatures are in the 20s and 30s,
and winds are generally running 10 to 20 mph out of the northwest
with some occasionally higher gusts over far northeast South Dakota
into west central Minnesota. Surface high pressure is over the
Missouri River valley region.

Elongated surface high pressure extending from southern Canada all
the way down to Texas will be moving very little over the next 36
hours. Cold, dry and relatively light winds expected during this
period. Guidance continues to generate freezing fog across portions
of southern North Dakota and northern South Dakota later tonight
into Thursday morning. So, this (areas of fog) is now part of the
forecast for tonight. Dense fog? Perhaps. Will monitor conditions
late this evening through the overnight to see if an advisory is
necessary.

The recent pattern change to persistent northwest flow aloft, where
the region has undergone a temperature plunge, looks to continue
through next Monday before there is any real chance for a warm up.
And that being said, it`s entirely possible that most of that "WAA"
is elevated and not realized at the surface, where many inches of
snow is expected to be in place across the entire northern plains
region and low level/near surface embedded cold air will be tough to
displace by low level WAA.

The next system (day after Thanksgiving) set to impact the region
will begin saturating the column down across central and north
central early Friday morning, eventually extending this saturation
process over into northeast and east central South Dakota by late in
the day on Friday, with snow then continuing overnight into Saturday
morning. Locations south of a line from Murdo to Faulkton to Milbank
may not see an end to falling snow on Saturday until closer to
mid/late afternoon. Beyond that, most of the forecast goes dry
again, despite there being multiple mid-level waves of low pressure
progged in the models to sweep southeastward through the region
between Saturday night and Wednesday of next week.

The primary mechanism responsible for this Friday/Saturday snow
event is strong WAA/frontogenesis in the low to middle portions of
the atmosphere. The low pressure system in question is noted on the
Water Vapor loop over the eastern Pacific ocean, heading toward the
Pacific Northwest. Banded snow on an east-southeast wind develops
during the first half of Friday over central/north central South
Dakota before slowly expanding over into northeast/east central
South Dakota Friday afternoon/evening. Model soundings do not show
enough saturation happening at Watertown for it to begin snowing
there until closer to 6 PM CST Friday. Friday night into Saturday,
the wind should switch around to a direction somewhere between
northwest and northeast, with snow gradually diminishing from
northwest to southeast in coverage throughout the day on Saturday.

Central/north central South Dakota water equivalent precipitation
amounts for this event are currently forecast generally between 0.10-
0.20inches of liquid. There is a 50-80 percent chance of that area
receiving more than 0.10in of liquid. Similarly, this region is
currently forecast to receive anywhere from 1-3 inches of snow with
locally higher amounts. There is a 70+ percent chance of receiving
at least an inch of snow and a 20-60 percent chance of receiving
more than 3 inches of snow throughout the Missouri River valley
region.

Northeast and east central South Dakota (and further east) water
equivalent precipitation amounts for this event are currently
forecast generally between 0.20-0.40inches of liquid. There is a 40-
80 percent chance of that area receiving more than 0.20in of liquid.
Similarly, this region is currently forecast to receive anywhere
from 3-5 inches of snow with locally higher amounts. There is a 40-
90 percent chance of receiving at least 3 inches of snow and a 30-60
percent chance of receiving more than 5 inches of snow across
northeast and east central South Dakota.

Behind this system, more low level CAA drops high temperatures down
into the upper single digits and teens above zero Sunday and Monday,
including low temperatures falling below zero Saturday night and
Sunday night. Wind chill values are currently forecast to fall into
the -10F to -20F range during said timeframe.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1135 AM CST Wed Nov 26 2025

Terminals KABR,KATY,KPIR,KMBG

KATY is the only terminal that remains in some category below VFR
(cigs) early this afternoon. Streamer of low clouds continues to
work south onto the Prairie Coteau, so not overly confident that
KATY will ever clear off today. Other then some late night/early
morning (IFR) fog potential at KMBG Thursday morning, VFR should
prevail over the next 24 hours at KPIR, KMBG and KABR. Guidance
has low clouds sticking around at KATY through the end of the TAF
valid period. Winds should go light and variable by early this
evening at KPIR/KMBG. But, KABR and KATY will probably maintain a
light northwest wind less than 10 knots, while surface high
pressure hangs on across western/central South Dakota overnight.

&&

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

$$

DISCUSSION...10
AVIATION...10