251
FXUS63 KABR 290006 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
606 PM CST Sun Dec 28 2025

.KEY MESSAGES...

- Northwest winds gusting from 35 to 50 mph through this evening,
  before diminishing overnight.

- A second wave of snow will drop south from North Dakota late
  this afternoon and through the evening. While additional
  accumulations will be between a dusting and 2 inches over
  northeast SD and west central MN, the combination of the new
  snow on the ground, falling snow, and the wind will lead to
  blowing snow that will frequently reduce visibilities below a
  half mile. Blizzard conditions are expected over portions of
  northeast SD and in west central MN.

- There is a 40% of snow on Wednesday over northeast SD and west
  central MN, but at this time, accumulations are expected to be
  less than an inch.

&&

.UPDATE...
Issued at 556 PM CST Sun Dec 28 2025

See below for an aviation forecast discussion for the 00Z TAFs.

&&

.DISCUSSION...
Issued at 258 PM CST Sun Dec 28 2025

As of 2pm, much of the falling snow is confined to far northeast SD
and into west central MN as the mid level dry slot has lifted
northeast. In the areas where there is falling snow, seeing
visibilities between 1/4 and 1 mile and then for most locations,
once the snow ends, the visibilities generally improve to above 4
miles. But are seeing a few spots where there was enough snow to
keep blowing snow visibilities around or below a mile, which does
lead to some concerns as the falling snow pivots back to the south
and into the area towards evening (even starting to show up in
southern ND in the latest radar trends). That pivot southward of the
trowal precip will be associated with the quick southeastward track
of the mid level low currently spinning in central SD. The main
question then becomes how strong will the snow be and when combined
with the existing winds (which may even trend up a touch as the low
level winds increase around 5kts and the pressure gradient
tightens). Thinking that conditions will be similar to earlier today
(maybe slightly lighter snow) and lead to another period of
visibilities below 1 mile and likely between a half and a quarter
mile. This period of snow will be pretty short lived (likely only 4-
6 hours), but when the snow is falling and if sustained winds are
25kts or higher, we`ll get blizzard conditions (per blowing snow
model research). Current forecast has sustained winds of 22-28kts
and that aligns with for sure advisory conditions and at times
blizzard conditions. Since it is close and sites in ND have
visibilities below a half mile with weaker winds, opted to upgrade
Roberts, Marshall, Grant, and Big Stone to a Blizzard Warning for
this evening. Farther west, did start up another Winter Weather
Advisory for McPherson, Brown, and Spink counties to account for the
combined falling/blowing snow expectations. The conditions will
improve pretty quickly between 04Z-07Z from north to south as mid
level dry air moves in behind the trowal and cuts out the larger
forcing. Blowing snow model captures this trend well, with percent
coverage of half mile visibility rapidly lowering between 06Z-12Z.
For the rest of the area, winds will gradually diminish through the
overnight hours and into Monday morning as a 1040mb high moves over
central SD by mid day Monday.

Behind the system producing the precipitation this evening, the
upper level pattern will be fairly consistent over the next 5-7 days
with a ridge over the west and a trough over the eastern CONUS. This
will lead to northwest flow aloft and bring a couple
clippers/shortwaves through the upper midwest on Tuesday and
Wednesday. The consensus from the ensembles is for Tuesday`s system
to slide through northern Minnesota, with only a low chance (5-10
percent) of producing precipitation in the west-central MN area.
Will mention that there is the potential for a rain/FZRA/Snow mix if
precipitation occurs, as soundings show initial temps aloft (around
900-850mb) being just above freezing. With the dry low levels, would
expect evaporative cooling to bring below freezing and bring snow
eventually. Of course, this is still a low chance of occurring, so
not going to try and pinpoint the exact p-type this far out. Also
will mention that there could be some drifting of the fresh snow in
northeast SD and west central MN, and as temps warm towards
freezing, it could create some icy spots on the roads in that area.

The second clipper system will track a farther to the southwest and
through western and central SD (1016mb low), with the snow falling
mainly through eastern ND, far northeast SD, and into central MN
late Tuesday night into Wednesday. Snowfall amounts still looking
light at this point, with NBM 25th-75th percentile amounts ranging
from 0 to 1 inch northeast of a line from Britton to Clear Lake.
Fortunately, with weak surface low moving across southwest/central
SD, don`t expect any strong winds with that snow farther to the
northeast and thus no blowing snow. Any visibility restrictions will
be associated with the falling snow.

For the rest of the period, no significant precipitation chances at
this point. Temps will warm ahead of the Tuesday clipper (highs in
the 30s to lower 40s) before settling back closer to normal
(although plenty of spread in the NBM 25th-75th percentile highs).
With the northwest flow aloft, the coldest temps will be in
northeast SD and warmest over the southwest.

Overnight Monday into Tuesday, the upper-level flow over SD becomes
more northwesterly as a trough sits to the east and a ridge builds
to the west. While this is happening, low level warm air advection
is helping to warm surface temperatures over central and
northeastern SD to be 10-15 degrees warmer than normal. This WAA
helps to provide some mixing, which will cause some of the stronger
winds aloft to reach the surface. While these winds won`t be as
strong as today`s winds, they will still be strong enough to cause
some drifting to patchy blowing snow over the Leola hills and the
Prairie Coteau, with 30-50% chance for gusts up around 30mph during
the afternoon in those areas.

The warm temperatures don`t last too long, as a surface low pressure
moves from Manitoba into MN during the day Tuesday, pushing cold air
back into northeastern SD Tuesday afternoon. This low pressure has
precipitation around it, which is forecast to stay mostly over MN.
However, some models have a bit of precipitation glancing far
northeastern SD and west central MN. There are very low chances for
precipitation over this area right now, but it should be kept in
mind when looking at upcoming model runs to see if the low`s track
shifts slightly and chances increase, especially since temperatures
will be going from warmer to colder during that time.

A cold frontal boundary attached to the low pressure in MN is
forecast to move into and through central and northeastern SD
Tuesday night into Wednesday. During the day Wednesday, the models
show a weak surface low pressure moving over central SD, tracking
along the edge of the cold front. This weak low pressure helps to
bring a little bit of WAA over central SD, which will keep
temperature at the surface warm while temperatures in the northeast
cool down. The interaction of the WAA and cold frontal boundary will
also help to cause a line of snow to develop. However, the models
still vary the location of this line, its timing, and the intensity
of the snowfall. This lowers confidence in the forecasting of the
line of snow, so it will need to be watched in the upcoming model
runs.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 556 PM CST Sun Dec 28 2025

Terminals KABR,KATY,KPIR,KMBG

Snow and gusty northwest winds are the primary items of focus in
the TAF period, and mainly between 00Z and 06z. Snow has pivoted
back south into all four terminals early this evening, with IFR
visbies and VFR/MVFR cigs at KATY/KABR and VFR/MVFR visbies and
cigs at KPIR/KMBG. Blowing snow in these strong northwest winds of
20 to 30 knots with gusts to 40 knots is adding to the reduced
visbies. That snow will depart pretty quickly between 04Z-07Z and
should see visibilities improve with the falling snow ending and
winds slowly decreasing late tonight into Monday morning.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory until 3 AM CST Monday for SDZ007-008-011-019>023.

     Blizzard Warning until 3 AM CST Monday for SDZ007-008-021.

     Winter Weather Advisory until midnight CST tonight for SDZ005-
     006-018>020-022-023.

     Wind Advisory until 9 PM CST this evening for SDZ006-018.

     Winter Weather Advisory until 3 AM CST Monday for SDZ011.

MN...Wind Advisory until 3 AM CST Monday for MNZ039-046.

     Blizzard Warning until 3 AM CST Monday for MNZ039-046.

&&

$$

UPDATE...10
DISCUSSION...SRF
AVIATION...10