972
FXUS63 KABR 062010
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
210 PM CST Sat Dec 6 2025

.KEY MESSAGES...

- Another round of light snow moves into north central South
  Dakota later this afternoon, continues southeast this evening.
  Around an inch or less accumulations with this system.

- Band of light snow moves west to east Sunday (40-60%). Inch or
  less type accumulations.

- Frontal passage Tuesday afternoon to generate northwest winds
  with gusts in excess of 50 mph through the evening/overnight.

&&

.DISCUSSION...
Issued at 145 PM CST Sat Dec 6 2025

Pair of bands of snow continue this afternoon, one migrating out of
the CWA into east central South Dakota, the other poised on our
doorstep in North Dakota headed into Mobridge/Aberdeen. CAMS
continue to support this second feature headed into our area to
dissipate, with only an inch type accumulations.

1030+ mb high pressure system moves over North Dakota extending
south southeast into the northeast of the state tonight. Warm
advection as this feature retreats Sunday is enough to generate
light snow thanks to about 5 microbars of lift in the dendritic
growth zone AOA 700mb. This persists for a few hours before drying
out in the DGZ and leaving us with just stratus.

The next clipper is rather weak Monday evening, mainly across North
Dakota. Milder 850mb temperatures, between +1 and +3C in the warm
sector overhead during daylight hours, however NBM sky cover is
suggesting little sunshine potential for the day.  Light westerly
flow and the cloud cover/milder air aloft will scour out the last of
the Arctic airmass at least.

The clipper that follows later Tuesday is the main feature to watch
this week. This is a much stronger system, down to around 985`ish
mb. A tight gradient, 20mb across the state, and pressure falls of
13 to 16mb ahead, and similar pressure rises in its wake, means
fairly good transport of winds aloft to the surface. Ahead of the
system, strong warm advection will still temper this somewhat,
with 1/2km winds of 30 to 40kts. By 00Z Wednesday, that has
increased to 50 to 65kts in the cold advection regime. BUFKIT
mixed tool verifies with several sites mixing into that 60kt zone.
EFI/shift of tails focuses on James valley west for those higher
probabilities for 60+ mph wind gusts.

What impact will 60mph winds have however, after a high temperatures
Monday above freezing, and Tuesday near 40 degrees with rain
showers. Depends on how much wrap around snow is generated, which at
this point is relegated to the far northeast of the state. As such
the main impact will be winds on high profiles vehicles and
powerlines, but the snow that is around should be heavily modified
and unblowable.

Another clipper follows for Wednesday night, following a track south
of the CWA. The Arctic airmass that has followed Tuesday`s clipper
isn`t quite as cold, but cold enough that the NBM probability p-
type is predominantly snow. NBM 25-75th QPF range is only about 0.1"
however deterministic GFS is coming in closer to a 0.5" swath/band,
so this may be smoothed out in extended ensembles given how far out
it is.


&&

.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 6 PM CST this evening for SDZ018-
     019-022-023.

MN...None.
&&

$$

DISCUSSION...07
AVIATION...07