203
FXUS63 KABR 141121 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
521 AM CST Sun Dec 14 2025

.KEY MESSAGES...

- Winds this afternoon will gust between 30 to 40 mph from the
Missouri River through the higher elevations of the Sisseton Hills.
These winds and recent snow over the past 24 hours will result in
low level drifting snow.

- Potential for Sisseton Hills downslope winds tonight, with gusts
of 35 to 45 mph, with localized higher gusts possible.

- Temperatures will rise to near and above normal Monday through
Wednesday, with highs mainly in the 40s Tuesday and Wednesday with
50s possible over south central SD Wednesday.

- Another Arctic blast has the potential to generate 40 to 60+ mph
wind gusts late Wednesday night into Thursday.

&&

.UPDATE...
Issued at 509 AM CST Sun Dec 14 2025

Updated discussion for the 12Z TAFs below.

&&

.SHORT TERM /TODAY THROUGH MONDAY AFTERNOON/...
Issued at 232 AM CST Sun Dec 14 2025

As of 2am, satellite and observations at and around KPIR have
reported just a small area of freezing fog coming off the Missouri
River, with viz down to a 1/4 mile. Otherwise, just a few high
clouds passing over the area with temperatures ranging from -4 at
KMBG, -9 at KABR, and -13 at KPIR (due to fresh snow here). Wind
chills are ranging in the teens to twenties below zero. The 1043mb
high pressure system will continue to track southeast, with the
center over IA by 12Z. The CWA will be on the northwest side of this
high and east of a surface trough/warm front stretching northward
and northwestward over the Rockies, south of a low over western
Canada. By this evening, the axis of the surface trough will be over
eastern MT/WY and the western Dakotas. With this setup, the pressure
gradient will be steepest over the western half of SD this morning
and in between the Mo and James River midday, with gusts of 20-
35kts. The steeper pressure gradients will then be over the James
Valley and eastward late this afternoon and evening.

As winds take on more of a southwest component late this
evening/tonight (and an impressive inversion sets up between 850-
900mb with temps at 15C!), we will see an increase in downsloping
winds off the Coteau. Both mean HREF/NBM indicate the potential max
gusts of 40-50 mph over and along the Coteau with the 50mph gust
potential from about 6pm to midnight along and around a line from
Summit to Brandt. After midnight, winds will shift out of the west
over the CWA with winds diminishing as the trough/warm front tracks
across the CWA. With these winds and recent snowfall over central SD
there is the potential for drifting snow, however, isolated areas of
blowing snow is possible that could reduce visibilities at times.
Snow over and along the Coteau should be crusted due to recent
rains, but they have recieved a small amount of snow since then. So
"most" of it should not be blowable, however, if we get 50 mph wind
gusts and there is some snow to blow (no additional snow expected),
it would be drifting to isolated areas of blowing snow. By Monday,
the warm front will be off to our east with winds shifting out of
the southwest by Monday afternoon with dry conditions continuing.

Temperatures will be "warmer" today than yesterday but still chilly
James Valley and eastward being on the backside of this high, with
high temperatures in the mid to upper teens to the lower 20s. With
the southerly flow/incoming trough highs over central SD will range
in the mid to upper 20s to upper 30s, warmest south central SD.
Overnight lows will range around 10 to the mid 20s. Temps will warm
after midnight into the mid/upper 20s per downslope winds on the
eastern slopes of the Coteau by 12Z Monday. By Monday peaking
heating, 925 temps will range from 0 to +10C with overall highs back
up in the upper 20s to upper 30s east of the MO and into the 40s
west of Mo River!

&&

.LONG TERM /MONDAY EVENING THROUGH SATURDAY/...
Issued at 232 AM CST Sun Dec 14 2025

The overall pattern doesn`t change much, though the slight shift in
the storm track observed over the next 24-48 hours translates
through the long term. The resultant storm track will allow for more
mild, modified Pacific airmasses though with intermittent intrusions
of Arctic air. Starting Tuesday 00Z there is a shallow ridge aloft
upstream and northwest flow overhead forcing mild air with 850mb
temperatures in the single digits to low teens C. This is almost 2
standard deviations above climo, and low level flow is westerly as a
clipper low moves across southern Canada.  The gradient actually
tightens up through the course of the day, so strengthening winds
even in a warm advection regime should aid in warming despite our
snowpack. NBM had highs in the 40s, with only a 3-5 degree 25th/75th
percentile range with the highest ranges over western/south central
South Dakota where its closer to 7-8F and guidance brings in a cloud
deck around 12kft.  Thus, aside from the impact of cloud cover, very
confident we will overcome the snowpack for a much deserved reprieve
from the cold weather. The only wrinkle is that the clipper up north
does trail a cold front, with a gradient on the backside of the core
of warmest air aloft, followed by a tighter gradient associated with
a surge in Arctic air. The core of the coldest air heads east-
southeast, into northeast South Dakota/Minnesota and is rather
transient, with return flow off the the high for Wednesday. NBM high
temperatures Wednesday are similar to Tuesdays` highs, but isn`t
nearly as warm aloft, and the low level flow orientation is
southerly. A stronger front comes through late Wednesday/early
Thursday with the associated surface low track just a little south
in comparison the previous deterministic runs. Regardless, a low
track moving through northern North Dakota puts us in an area where
precipitation is much more transient and we will initially be dealing
with rain showers within the milder airmass, with a transition to
snow showers in the post frontal, low level dry adiabatic and weakly
convectively unstable environment. Winds will be the story however,
with GFS BUFKIT mixed winds again into the 60kt range. NBM 25th/75th
range for peak winds runs between 45-50mph (lower bound) and 55-
70mph (upper bound)... CWA wide.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 509 AM CST Sun Dec 14 2025

Terminals KABR,KATY,KPIR,KMBG

Low stratus over KMBG continues to produce light snow/flurries and
LIFR cigs. This may continue for the next couple of hours before
ceilings increase to VFR. Otherwise, VFR cigs expected for the
rest of the TAF sites through Monday morning. Winds will increase
out of the south today with gusts of 25-35kts, mainly east of the
Missouri River, with the highest gusts over the higher elevations
of the Sisseton and Leola Hills. KATY will remain gusty tonight,
per downsloping winds. Low level wind shear around 2000ft is
forecast tonight into early Monday morning at KABR/KATY/KMBG
between 30-45kts, highest over KATY.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Cold Weather Advisory until 10 AM CST this morning for
     SDZ006>008-011-018>023.

MN...Cold Weather Advisory until 10 AM CST this morning for MNZ039-
     046.

&&

$$

UPDATE...MMM
SHORT TERM...MMM
LONG TERM...07
AVIATION...MMM