859
FXUS63 KABR 131144 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
644 AM CDT Fri Mar 13 2026

.KEY MESSAGES...

- The probability of exceeding 6 inches of snowfall this weekend
  has increased to 70 to 90% across the forecast area. Winds of 30
  to 45 mph will lead to blowing/drifting snow and blizzard like
  conditions mainly east of HWY 83.

- Very cold air follows with temperatures Sunday into Monday some 15
  to 25 degrees below normal.

&&

.UPDATE...
Issued at 632 AM CDT Fri Mar 13 2026

Aviation discussion updated below for the 12Z TAFs. Will also let
the High Wind Warning expire at 12Z for the eastern CWA as winds
have decreased below criteria.

&&

.DISCUSSION...
Issued at 255 AM CDT Fri Mar 13 2026

As of 08z, the stronger winds are slowly dying back over central SD
and should start decreasing over northeastern SD as a clipper low
moves east. Though it will be about mid-morning before winds around
and above 35mph to move east of the Prairie Coteau and out of the
area. A high surface pressure is moving over SD through the morning,
and will help to calm the winds and keep precipitation chances low.
Cold air has been moving into central and northeastern SD with these
strong winds, and will cause temperatures today to be slightly
colder than yesterday, with highs in the 30s. As temperatures
decrease, RH values are recovering, which will help to reduce the
fire weather risks. Additionally, the decreasing winds are also
helping to reduce the risk.

The high pressure moves out of the area this afternoon and evening
and models are forecasting a line of precipitation to move into
central SD during the late afternoon and spread into northeastern SD
overnight on the northern side of the developing Colorado low. This
precipitation looks to be mainly snow and could cause snowfall
accumulations of a light dusting along the edges up to 3 inches in
north central SD by Saturday afternoon. The Colorado low continues to
develops and starts to move east Saturday evening into Sunday
afternoon, which is when the bulk of the snow is forecast to fall.
The is still some uncertainty in the location and amounts of the
highest snowfall. The models have shifted the track of the low
pressure to the north, which has caused an increase in snow amounts
in the models and shifted them slightly. There is a 70-90% chance
for 6 plus inches of snowfall accumulation in the James River valley
and eastward, with the highest amounts and chances over the Sisseton
hills and to the east, with a 50-70% chance for 10 plus inches.
There is still a fairly large spread of snowfall totals in the
models leading to some uncertainty, with 5-8 inch difference in
ensemble 25th to 75th percentile snow total amounts across
northeastern SD.

Saturday afternoon and evening, as the bulk of the snow starts
falling, cold air also begins to move into the area. The cold air
advection will help stronger winds aloft to reach the surface. There
is a 30-40% chance for winds to gust above 35 mph Saturday afternoon
which increases overnight into Sunday morning to be 50-80% chance
mainly east of the Missouri River. These strong winds will likely
combine with the falling snow and could create blizzard like
conditions east of HWY 83 and especially over and along the Prairie
Coteau. Travel could become hazardous Saturday night into Sunday due
to blowing snow causing reduced visibilities and with the copious
amounts of snow forecast to accumulate.

This push of cold air will also cool temperatures Sunday and Monday
15-25 degrees colder than normal, with wind chills looking to drop
into the negative teens to -20. High surface pressure is forecast to
move in behind Colorado low and the snow Sunday night into Monday,
which will help to keep precipitation out of central and
northeastern SD and cause winds to calm down Monday.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 632 AM CDT Fri Mar 13 2026

Terminals KABR,KATY,KPIR,KMBG

Lingering MVFR CIGs will affect KATY/KABR at the start of the TAF
period before trending VFR by mid morning. -SN/SN will move into
the region this evening, with a return to MVFR CIGs as well.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Storm Watch from Saturday afternoon through Sunday
     evening for SDZ003>011-015>023-033>037-045-048-051.

MN...Winter Storm Watch from Saturday afternoon through Sunday
     evening for MNZ039-046.

&&

$$

UPDATE...TMT
DISCUSSION...12
AVIATION...TMT