980
FXUS63 KABR 020533
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
1133 PM CST Mon Dec 1 2025

.KEY MESSAGES...

- Freezing fog with visibilities down to 1/4 at times, and light
  icing, will remain possible early this morning, mainly near the
  Missouri River.

- A quick moving disturbance will push through the region Tuesday
  into early Wednesday, kicking off a 30-50% chance of light snow
  over north central and northeast South Dakota and a wintry mix
  of mainly rain/snow across central South Dakota.

- Very cold air across the region Wednesday and Wednesday night,
  with lows in the single digits below and teens below zero. Wind
  chills may reach 15 below to 25 below zero in the James River
  valley.

- Snow chances (20-35%) return Friday/Saturday as more clipper
  systems potentially move through the region.

&&

.UPDATE...
Issued at 1133 PM CST Mon Dec 1 2025

A quick update was done to include the freezing fog near the
Missouri River. Both PIR and MBG have reported freezing fog with
visibilities down to 1/4 mile. Webcams in PIR show this shallow
fog layer well, with not as robust spacial coverage on MBG webcams
at this time. Expect fog to diminish in coverage and intensity by
10-12Z as high clouds move in from the west and surface winds
increase slightly and shift out of a more southerly direction.

&&

.DISCUSSION...
Issued at 115 PM CST Mon Dec 1 2025

At 1 PM CST, skies are mostly sunny. Southwest winds are around 5 to
15 mph with some of the ridge tops gusting up over 25 mph.
Temperatures are warming through the single digits above to teens
above zero. There are even a few places (south central South Dakota)
trying to nudge their way up into the low 20s.

A surface trof/warm front is over the northern high plains/Dakotas
region this afternoon. The front is forecast to advance eastward,
nearing the border of Minnesota and the Dakotas around 3 PM CST
Tuesday. Low level WAA really gets going over this CWA later this
evening and during the overnight hours tonight into Tuesday. Surface
winds will maintain a direction somewhere between southerly and
westerly tonight through Tuesday. Most of the WAA period will be
spent saturating the column down. But, there may be times between
09Z Tuesday and 03Z Wednesday, when enough forcing/lift for
saturation may happen, and light precipitation would occur. Very
limited qpf with this scenario in the models/ensembles. The CWA will
probably maintain some sort of horizontal thermal gradient, where
central South Dakota could warm up enough that precipitation
transitions from snow to freezing rain to rain, while north central
and northeast South Dakota stay cold enough for precipitation to
just be snow. When the cold front chases this warmer air southward
out of the region Tuesday night (basically at or after 03Z
Wednesday), there could be enough of a "wringing out" of any
available low level moisture, to produce a period of CAA stratus and
light snow/snow showers briefly in the forcing/lift zone of the cold
fropa. Otherwise, it looks like breezy/windy north winds develop
Tuesday night, post-cold-frontal, with sustained winds establishing
in the 15 to 30 mph range with some occasional higher gusts.

Tonight, temperatures will cool off rapidly after ~4 PM CST with
clear skies and generally light south or southwest winds. Later
tonight, there should be increasing cloudiness over the CWA and low
level WAA kicking in, such that temperatures will begin to slowly
warm late tonight into Tuesday morning, especially across central
and north central South Dakota. The warming continues on Tuesday
from west to east, as warmer air overspreads the vast snowfield in
place over the Dakotas and Minnesota. Then, temperatures should turn
sharply colder behind a southward moving cold front Tuesday night.

So, upper ridge over the western CONUS/upper trof over the eastern
CONUS describes the basic flow pattern aloft throughout the period.
But, it is an active period of northwest flow with several shortwave
impulses forecast to sweep southeastward into the country`s mid-
section throughout the period. And, a few of these shortwaves are
expected to bring precipitation chances through this CWA.

For now, looking at one possible brief run-in with precipitation on
Friday, and then another following close on its heels on Saturday.
These are fast-moving, low-qpf producing systems, so confidence is
pretty low just now on when/where/how much details.

Also, beyond the below normal cold temperatures slated for
Wednesday/Wednesday night in the post-cold frontal environment, low
confidence in the temperature forecast with 25th to 75th percentile
spread in both low and high temperatures exceeding 5 degrees (and
a lot of 10+ degree spreads) throughout the entire period beyond
Wednesday. Even Wednesday/Wednesday night`s spreads are more than 5
degrees. But, in that case, the question is will it be really cold
or really, really cold! So, the warm up for Thursday/Friday and
again next Monday is in question.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1133 PM CST Mon Dec 1 2025

Terminals KABR,KATY,KPIR,KMBG

LIFR conditions in freezing fog have developed at MBG and PIR
by 05Z with visibilities down to 1/4SM and VV001. Expect freezing
fog to diminish in coverage and intensity by 10-12Z as high
clouds move in from the west and surface winds increase slightly
and shift out of a more southerly direction. Otherwise, at least
MVFR conditions in fog were also introduced to ABR/ATY by 08-09Z
through 12-16Z Tuesday. Confidence is low in the lower LIFR
conditions developing at ABR and ATY overnight.

&&

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

$$

UPDATE...06
DISCUSSION...10
AVIATION...06