174
FXUS63 KABR 101925
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
125 PM CST Wed Dec 10 2025

.KEY MESSAGES...

- Light snow showers/flurries continue over northeastern SD into
  west central MN this afternoon. Little to no additional
  accumulation is expected.

- Wintry mix of snow, sleet and freezing rain expected across
portions of central, north central and northeast South Dakota from
Wednesday night through early Thursday evening. Ice accumulation of
a tenth of an inch or less. Snow accumulation generally at or below
2 inches.

- Highs Friday and Saturday will be in the single digits to teens,
coldest Sunday morning. Wind chill values Saturday and Sunday
morning could be as low as -20F to -30F degrees.

- Another round of snow will be possible Friday night into Saturday.
There is still a lot of uncertainty in the track and amounts for
this potential event, but there is currently a 20-50 percent chance
of seeing up to 3 inches of snow across portions of central and
north central South Dakota.

&&

.UPDATE...
Issued at 124 PM CST Wed Dec 10 2025

Plenty of clouds and flurries/light snow showers remain over
northeastern South Dakota into west central MN, enough to bring
the visibility at ETH/VVV/ATY down to 4-6 miles early this
afternoon. Little to no additional accumulation is expected. Winds
continue to slowly diminish, with gusts of 25mph or less now east
of the James River. Winds will continue to weaken through the
afternoon. Otherwise, we`re looking into the upcoming light snow
west of the MO River late this afternoon to become a wintry mix
after 06Z. Freezing rain will be the main weather type from north
central SD through Pierre (changing to mainly rain after 16Z
Thursday) and Miller into mid afternoon Thursday. The current
headlines look on track at this time, with some adjustments
possible over portions of north central SD where ice accumulations
have increased.

&&

.SHORT TERM /TODAY THROUGH THURSDAY AFTERNOON/...
Issued at 407 AM CST Wed Dec 10 2025

At 3 AM CST, across most of central/north central South Dakota,
clouds have cleared off. It`s partly to mostly clear there. Further
east, things are still cloudy as light snow continues to sweep
southward on the back of this most recent clipper system that is now
positioned over northern Iowa and continuing to move away from the
region. With the sustained northwest winds still running in the 25
to nearly 40 mph range throughout and east of the James River
valley, including occasionally higher gusts, where light falling
snow continues, have extended the winter weather advisory out in
time to 6AM CST. There haven`t been too many instances of
significantly reduced visibility (less than 1/2mi) in
falling/blowing snow. Still, seeing 1-2mi visbies in regional
observations, so am content with that extension. Anticipating the
majority of falling snow to be done by roughly 6 AM CST, with wind
speeds also falling off enough to be able to expire the remaining
High Wind Warning headline covering northeast South Dakota and west
central Minnesota at 6 AM CST this morning. Temperatures have been
steadily falling this morning into the upper teens to mid 30s.

Short-lived surface high pressure will be centered over the CWA by
around 21Z this afternoon. Although, back-wash low stratus behind
yesterday/last-night`s clipper system will likely be hanging around
all day across the eastern third of forecast zones. The western two-
thirds of the CWA may see some sunshine to start things off today,
but by this afternoon, a fresh new round of clouds will be streaming
into the region from the west/northwest. Northwest flow aloft
continues the wave-train of low pressure systems, with the next
round of precipitation developing later tonight and continuing into
early Thursday evening, in the form of a combination of snow, sleet
and freezing rain. The RRFS, with support from the NAM/HREF model
families has snow developing into the Mobridge area by midnight
tonight. WAA within the saturated layer (between ~3kft and 6kft)
warms the column enough to transition things over to sleet and then
eventually freezing rain. This zone of warming continues to shift
east, reaching the James River valley by 12Z Thursday. The
NAM/HRRR/RAP are a little bit more aggressive than the RRFS with how
far east that warm nose gets pushed. Suffice it to say, the ensemble-
based p-type guidance did introduce enough warming into the layer on
Thursday to change snow over to freezing rain/sleet even as far as
Watertown. So, with sleet and ice accumulation now showing up over
onto the Coteau (generally less than a tenth of an inch), along with
an inch or two of snowfall, have extended the winter weather
advisory over onto the Prairie Coteau accordingly.

Once temperatures settle into today`s highs, there really will not
be much movement of surface temperatures (high`s or low`s) through
Thursday. Perhaps with the low level WAA that is forecast to
accompany this next round of winter precipitation, high temperatures
on Thursday may be able to climb 5 or 6 degrees. But, that`s about
it.

&&

.LONG TERM /THURSDAY EVENING THROUGH TUESDAY/...
Issued at 407 AM CST Wed Dec 10 2025

It appears that there might just be a pattern change by early next
week. The positive PNA pattern looks to hold until then, though.
PoPs are increasing (now into the likelys 55-70%) for Friday night
into Saturday morning, highest across central South Dakota, with the
next clipper wave forecast to work through the region. With this
system, it looks like it will be all snow, as the low level CAA that
ensues after the mid-week wintry mix event should persist until
enough cold air is over the region that p-type would just be all
snow. In fact, so cold will it potentially be, that SLR`s may again
be pushing past 18-20:1 and going higher than that when it`s all
said and done. A lot of the column is going to be in or close to
being in the DGZ when this event happens.

Otherwise, beyond that system, most of the rest of the extended from
Saturday night through next Monday is dry, as the upper level ridge
over the western CONUS is progged to shift over into the central
part of the country before flattening out, leaving a zonal or near
zonal flow pattern in place rolling into Tuesday of next week. And,
that should translate into a bit of a warm up heading into Monday
and possibly Tuesday of next week. Not that mixing will get up to
850hpa next week, but the anomaly signal at 850hpa is telling. The
ENS 850hpa thermal anomaly is 1.5 to 2 standard deviations above
normal for next Monday. Similar (a little bit less "up to 1.5 S.D.)
in the NAEFS output for early next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 124 PM CST Wed Dec 10 2025

Terminals KABR,KATY,KPIR,KMBG

VFR conditions persist at PIR, with MVFR ceilings elsewhere.
Before high clouds moved over and obscured the lower clouds, it
looked like MBG was on the edge of the lower clouds. There is some
breaking up of the cloud deck west of ABR with VFR ceilings
expected to return around 21Z. Light snow with temporary MVFR
reductions in visibility continue at ATY through 21Z. Otherwise, a
wintry mix is expected overnight through Thursday. On the cold
side, -SN will be the main precipitation type at ATY (dropping to
IFR potentially after 15Z Thursday). ABR will be on the edge of
-SN/FZRA/IP after 13Z Thursday. PIR/MBG have the higher chance of
 experiencing ice accumulations of 0.10" or higher overnight into
 Thursday. PIR is expected to warm high enough for -FZRA to change
 to -RA by 17Z Thursday, with that warming line nearing MBG as
 well.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory from 6 PM CST /5 PM MST/ this evening to
     noon CST /11 AM MST/ Thursday for SDZ003-004-009-010-
     015>017-033>037-051.

     Winter Weather Advisory from midnight tonight to 6 PM CST
     Thursday for SDZ005-006-018.

     Winter Weather Advisory from 6 AM to 6 PM CST Thursday for
     SDZ011-019>023.

MN...None.
&&

$$

UPDATE...06
SHORT TERM...10
LONG TERM...10
AVIATION...06