096
FXUS63 KABR 132333 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
633 PM CDT Fri Mar 13 2026

.KEY MESSAGES...

- A band of light snow will develop over portions of central and
  north central South Dakota tonight and drift northward into
  North Dakota Saturday morning. A general 1 to 2 inches, with
  locally higher amounts, is expected.

- A Wyoming Low will bring snow, heavy at times, for the weekend.
  The probability of exceeding 6 inches of snowfall has increased
  to 70 to ~100% across the forecast area, especially north of
  U.S. Highway 14 from Saturday afternoon through mid day Sunday.
  There is a 55-85% chance of 12 inches or more on the eastern
  half of the Prairie Coteau eastward into Minnesota for the same
  time period.

- Sustained winds 25 to 35 mph with gusts 40 to 50 mph develop
  Saturday night and lead to blowing/drifting snow and white
  out/blizzard conditions over much of the region.

- Very cold air follows with temperatures Sunday into Monday some
  15 to 25 degrees below normal. Wind chill values heading into
  Monday morning are expected to be in the teens below to 20s
  below zero.

- Beyond Monday, much above normal temperatures are expected from
  Tuesday through Friday.

&&

.UPDATE...
Issued at 626 PM CDT Fri Mar 13 2026

Light snow continues from Phillip to Chamberlain this evening and
will move north tonight. No major changes are planned to the
current forecast at this time, but will adjust hourly pops as
needed.

&&

.DISCUSSION...
Issued at 235 PM CDT Fri Mar 13 2026

At 2 PM CDT, skies are partly to mostly cloudy.  Winds have
decreased, still from the north, around 5 to 15 mph. Temperatures
are in the 20s and 30s. A few flurries or some very light snow may
be observed out across the Missouri River valley, westward, due to
an active upper jet stream pattern over-top a stout mid-level
baroclinic zone draped over the northern plains, but little in the
way of accumulating snow is expected this afternoon.

The previously mentioned upper jet stream and mid-level baroclinic
zone positioning should activate tonight with a transient mid-level
shortwave working through it. A band of light snow is expected to
form over the CWA tonight and gradually drift northward into North
Dakota Saturday morning. Guidance maintains a general 1 to 2 inches
(with locally higher amounts because of its banded nature) of snow
is possible tonight into Saturday morning. Wind tonight into
Saturday morning should settle into an east or southeast direction
generally 5 to 15 mph with some areas seeing gusts up to 25 mph. So,
not expecting a strong wind/blowing snow issue with this initial
banded event. Part of it may still be clinging to far northern South
Dakota forecast zones, but most of the CWA should be experiencing a
break in the snowfall potential Saturday morning/mid-day before the
next band of moderate to, at times, heavy snow develops Saturday
afternoon/evening when a Wyoming Low lifts out of the Rockies and
works its way east-southeast into Nebraska.

North of U.S. Highway 14, most of the forecast area sits in a 60 to
~100 percent probability of receiving 6 or more inches of snow from
Saturday afternoon to 7 AM Sunday (with a couple additional inches
of snowfall possible between 7 AM Sunday and 7 PM Sunday mainly over
the Prairie Coteau east into Minnesota. Up to 50 miles either side
of a line from about Kenel, SD to Milbank, SD there is a 65 to 85
percent probability of receiving 8 or more inches of snow during
this same timeframe. HREF 1-2in/hr snowfall rates are showing up
quite a bit Saturday night into Sunday morning over the CWA. This
also is confirmed in model cross-sections. Can`t rule out a couple
of embedded meso-scale bands of heavy snowfall withing the larger
banded snow. Ensemble guidance currently showcases much of the
CWA picking up 0.50-0.75 inches of water equivalent precipitation
from this upcoming event. Winter Storm Warning and Winter Weather
Advisory headlines have been issued for Saturday afternoon/evening
through the late night hours Saturday night for these potential
heavy snow accumulations.

If sustained winds run up to 25 to 35 mph with gusts to 45 mph
(which guidance suggests is highly probable - 55-95% chance), and
temperatures when the heaviest snow is falling are also falling from
the low 30s through the low 20s, and snowfall rates are 0.5in/hr,
the blowing snow model output reveals that there is a 70% chance of
occasional scattered white out/blizzard conditions. Adjust the
snowfall rate up to 1.0in/hr, and the bsm output increases to a 92%
chance of constant/near constant whiteout/blizzard conditions from
~10 PM CDT Saturday through ~Noon CDT Sunday. Snow should be
tapering off from west to east on Sunday. As the snowfall ends,
visibility is expected to improve. The probability of less than one-
half mile visibility in blowing snow (no falling snow) drops to
~35% or less. So, white out/blizzard potential becomes
brief/isolated, at worst. Certainly, ground level blowing and
drifting will remain a problem on area roadways Sunday afternoon
into, at least, Sunday evening, until the winds/gusts diminish.
Some guidance suggests the blustery winds won`t subside until
after 06Z Monday. A Blizzard Warning has been posted for all but
north central (where blizzard conditions are marginal/lowest
forecast confidence here at the moment) South Dakota forecast
zones in this CWA from late Saturday night through the day on
Sunday.

With the departure of this low pressure system, and a fresh deep
snowpack on the ground, temperatures should tumble into, at least,
the single digits either side of zero. Wind chill values
throughout and east of the James River valley are forecast to drop
into the teens below and 20s below zero.

Monday through Friday...Upper level ridging takes over across the
western half of the CONUS. Guidance depicts two or three transient
upper waves riding down the backside of this strengthening ridge,
each with its own period of mid/upper level WAA that may be able to
gen-up a couple of short-lived light precipitation events next week,
particularly centered on Monday night and again on Tuesday night.
Beyond that, the Ensembles temperature anomalies tables showcase
850hpa standardized anomalies 2-3 standard deviations above normal.
And the 6-10 day and 8-14 day temperature outlooks support this. So,
quite toasty warm, probably warm enough to invoke hydro concerns, if
this upcoming new/deep snowpack melts too fast.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 626 PM CDT Fri Mar 13 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will persist early this evening until snow moves
in. A light band will affect KPIR and KMBG this evening while
other sites may not see any snow until early Saturday morning.
MVFR/IFR vsby and cigs are expected once the snow begins. Blowing
snow will be possible after 15z Saturday as easterly winds
increase.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Storm Warning from 1 PM Saturday to 3 AM CDT Sunday for
     SDZ007-008-011.

     Blizzard Warning from 3 AM to 7 PM CDT Sunday for SDZ007-008-011-
     020>023.

     Winter Storm Warning from 1 PM CDT /noon MDT/ Saturday to 1 PM
     CDT /noon MDT/ Sunday for SDZ003-004-009-015-016-034.

     Winter Storm Warning from 1 PM Saturday to 1 AM CDT Sunday for
     SDZ005-006-010.

     Blizzard Warning from 1 AM to 7 PM CDT Sunday for SDZ005-006-010-
     017>019-036-037.

     Winter Storm Warning from 7 PM Saturday to 1 AM CDT Sunday for
     SDZ017>019-036-037.

     Winter Storm Warning from 7 PM Saturday to 3 AM CDT Sunday for
     SDZ020>023.

     Winter Weather Advisory from 10 PM CDT /9 PM MDT/ Saturday to 4
     AM CDT /3 AM MDT/ Sunday for SDZ033-035-045-048-051.

     Blizzard Warning from 4 AM CDT /3 AM MDT/ to 4 PM CDT /3 PM MDT/
     Sunday for SDZ033-035-045-048-051.

MN...Winter Storm Warning from 1 PM Saturday to 3 AM CDT Sunday for
     MNZ039-046.

     Blizzard Warning from 3 AM to 7 PM CDT Sunday for MNZ039-046.

&&

$$

UPDATE...20
DISCUSSION...10
AVIATION...20