653
FXUS63 KABR 061739
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
1139 AM CST Sat Dec 6 2025

.KEY MESSAGES...

- Snow returns Saturday. 1 to 4 inches of accumulation is
  expected through Saturday afternoon, with highest amounts
  expected in east central South Dakota. A Winter Weather Advisory
  remains in effect for parts of east central South Dakota.

- There will be periodic lower chances for precipitation (20-40%)
  beginning Sunday and continuing through early next week, as more
  weak weather systems have the potential to move through the
  region.

- Strong northwest winds of 20 to 35 mph with gusts in excess of
  45 mph are a concern from late Tuesday afternoon through
  Wednesday morning.

&&

.UPDATE...
Issued at 1130 AM CST Sat Dec 6 2025

The band of snow has shifted closer to between Miller and Redfield
towards Huron and continues to remain mostly stationary overall.
Upstream we can also spot another band of snow in the Bismarck
area, and this feature heads southeast later this afternoon into
the evening. CAMS do have this weakening but its something that
will need to continue to be metwatched especially in regards to
aviation/TAFs.

See below for an update to the aviation discussion.

&&

.SHORT TERM /TODAY THROUGH SUNDAY AFTERNOON/...
Issued at 258 AM CST Sat Dec 6 2025

Main focus in the near-term period continues to be the incoming low
pressure center that is expected to bring precipitation to the
forecast area. Ensemble means currently show between 0.10"-0.20" of
liquid equivalent precipitation through Saturday evening. Model
soundings indicate that snow will be the dominant precip type, and
there will be little chance for anything else due to temperatures at
both the surface and aloft expected to remain below freezing through
the event. Expected snow ratios are around 15:1 based on model
soundings, which will translate to around 2" across the forecast
area. The highest totals are expected over eastern South Dakota,
where NBM 90th percentile values are around 3 inches. No changes
have been made to the Winter Weather Advisory, in effect from 9 AM
to 6 PM CST for Spink, Clark, Hamlin and Deuel counties, where the
accumulations are expected to be highest. Timing wise, the highest
QPF totals are expected Saturday morning and afternoon, before
tapering off Saturday evening.

With this system, the winds bring an additional element to the
forecast. Gusts up to 30 miles per hour are anticipated between the
James River and the Missouri River this afternoon. The timing of
these winds will most likely be after the peak precipitation time in
that area, so impacts may be marginal. However any falling snow or
potentially the fresh snow on the ground could be moved around by
the wind and potentially reduce visibility and make travel dangerous
at times. Winds will not be strong enough nor will snowfall rates be
heavy enough for any widespread blowing snow impacts, and anything
that does come together will be isolated.

Behind Saturday`s system, another clipper comes down into the
forecast area Sunday and will bring additional snow to northern
South Dakota. Only a few hundredths of liquid equivalent are
expected, mainly during the daytime hours. This will translate to
about a half an inch in additional accumulation, with fairly broad
coverage across north central and northeastern South Dakota. NBM
90th percentile (as a proxy for a "worst-case" scenario) for this
event only reaches pockets of 1" in additional accumulations, so it
is safe to say this will be a fairly low-impact snow event on
Sunday.

&&

.LONG TERM /SUNDAY EVENING THROUGH FRIDAY/...
Issued at 258 AM CST Sat Dec 6 2025

When the period opens Sunday evening, light snow is expected to be
still falling across the eastern half of the CWA, working its way
east into Minnesota. The flow pattern compared to 24 hours ago has
not changed, a positive PNA pattern of upper ridge over the western
CONUS and upper trof over the eastern CONUS, placing this CWA in
northwest flow aloft. Models maintain that several transient areas
of clipper-like low pressure will move through the northern plains
in this upper level steering flow.

Initial low level WAA setting up over the CWA on Monday is fairly
strong, lingering into Tuesday before a strong cold front sweeps
through. High temperatures on Monday warm up into the 30s and 40s
across much of the CWA, despite snow on the ground. Tuesday could be
even warmer, with highs in the upper 30s to lower 50s thought
possible prior to Tuesday`s strong cold frontal passage. Strong
winds at 0.5km and higher are not expected to be felt at the surface
during the warm up on Monday. When the second surge of strong winds
in the warm sector kick in on Tuesday, there is expected to be a
period in the mid to late afternoon through the overnight hours
Tuesday night when sustained winds could exceed 40 mph and gusts
could exceed 58 mph. ENS EFI wind gusts signal is beginning to latch
on to the potential for strong wind now for Tuesday afternoon/night.
Will continue to monitor wind forecast trends, but a High Wind Watch
may be needed within the next couple of days for Tuesday/Tuesday
night. In addition to the potential for strong winds, there is some
potential for rain on Tuesday (20-40 percent chance of a quarter
inch or more of water equivalent precipitation north of a line from
Leola to Milbank. The potential for a little bit of freezing or
frozen precipitation p-type also clings to the far
northern/northeastern forecast zones Tuesday into Tuesday night,
although, still seeing a signal for the heaviest, most
meaningful/hazardous precipitation potential to reside across North
Dakota into Minnesota right now for Tuesday/Tuesday night. Arctic
cold air floods into the region from the north for Wednesday through
the end of the period. Additional chances for precipitation (snow p-
type) show up Wednesday night into Thursday.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1130 AM CST Sat Dec 6 2025

Terminals KABR,KATY,KPIR,KMBG

Tracking two areas of snowfall. The first is currently moving away
from KMBG, clipping KABR and headed towards KATY. This is mainly
responsible for MVFR VISBY/CIGS, with the worst of it (IFR VSIBY
in SN) missing the main terminals in the CWA. Late this afternoon
that second area coming down is expected to mainly impact
KABR/KMBG with MVFR VISBY. Overall there will be little change to
CIGS for all terminals through the TAF period.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory until 2 PM CST this afternoon for SDZ017-
     037.

     Winter Weather Advisory until 6 PM CST this evening for SDZ018-
     019-022-023.

MN...None.
&&

$$

UPDATE...07
SHORT TERM...BC
LONG TERM...10
AVIATION...07