167
FXUS63 KABR 271115 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
515 AM CST Thu Nov 27 2025

.KEY MESSAGES...

- Snow will return Friday into Saturday. Currently, there is a 30-80
percent chance of receiving more than 3 inches of snow throughout
central and northeastern SD, and a 30-70 percent chance of receiving
more than 5 inches of snow across central SD with this upcoming snow
event.

- Below normal temperatures will continue through the beginning of
December. Below zero wind chills area possible over northern SD each
morning Thursday through Sunday. Wind chills will fall into the
teens to near 20 below zero Sunday, Monday and Tuesday mornings.

&&

.UPDATE...
Issued at 514 AM CST Thu Nov 27 2025

Updated for the 12z Aviation Discussion below.

&&

.SHORT TERM /TODAY THROUGH FRIDAY AFTERNOON/...
Issued at 423 AM CST Thu Nov 27 2025

As of 10z, low clouds and fog have move in over north central and
northeastern SD. These low clouds and fog are causing localized
areas of lower visibilities at times. The fog should dissipate
this morning after the sun rises. An elongated high surface
pressure has moved in over central and northeastern SD today,
which will help to keep precipitation out and winds light.
Temperatures will be 5-15 degrees colder normal for the holiday
and Friday. High temperatures through Friday will be in the low
30s over south central SD and in the upper teens to 20s over
northern SD and west central MN, with low temperatures in the
teens to single digits. Wind chills will get down to the single
digits and the single digits below zero tonight.

Friday, the upper-levels have a small/weak ridge moving over SD. In
the mid- to low- levels under the ridge, a line of WAA pushes into
central SD Friday morning. This line of WAA has frontogenesis along
it that will help to develop a band of snow starting Friday morning.
This band of snow will move into central SD Friday morning before
slowly spreading to the east. There looks to be an strong initial
surge of snow Friday over an areas between the Missouri River and
James River. While models have place the highest rates Friday over
Walworth/Edmunds county to the southeast over Hyde/Hand county over
the past couple of runs, the highest snow totals could move due to
where the band and frontogenesis sets up on Friday.

Snowfall amounts during the day Friday until Friday night shows a
line with 30-80% chance for 3 inches or more from Mobridge to Miller
with the highest chances. The lower chances (around 20-40%) at the
edges of the line which includes Aberdeen to Clark on the eastern
edge of the line and Pierre on the western edge. There is then a 30-
60% chance for greater than 5 inches of snow until Friday evening
over southern Edmunds, Faulk, Hyde, and Hand counties as well as
slightly lower chances on the western edge of Spink county. These
chances increase as the overnight into Saturday time periods are
included (see long-term discussion below). Winds pick up slightly
Friday under the band, with gusts in the afternoon forecast to get
up to 25-30mph, strongest to the southwest of the highest snow
rates. These winds could lead to localized areas of patchy blowing
snow in central SD Friday. The snowfall probabilities Friday and the
ones on Saturday (more on this below) in combination with the fact
that this event will be happening the day after Thanksgiving and
many will probably be trying to travel, have lead to a winter storm
watch being issued for a few counties with the highest snow totals.
This watch area will most likely need to be updated as snow totals
continue to shift locations and amounts.

&&

.LONG TERM /FRIDAY EVENING THROUGH WEDNESDAY/...
Issued at 423 AM CST Thu Nov 27 2025

The main focus in the long term will be the ongoing snow event at
the start period along with much below normal temperatures
persisting through early December. Beginning 00Z on Saturday, a
fairly potent looking 500mb trough is progged to be tracking
eastward out of the Central Rockies into portions of the
Central/Southern Plains. This upper wave will have induced a 1006mb
Colorado low pressure system that is progged to track eastward into
KS/OK with an inverted trough extending northward into NE and SD.
During the daytime hours on Saturday, guidance takes this storm
system northeastward toward St. Louis by Saturday night and
eventually into the central and eastern Great Lakes the latter half
of the upcoming weekend.

A northwest to southeast oriented band of snow will already be
underway by the beginning of this period. There remains decent
agreement among guidance in tracking this snow east to southeast
during the day on Saturday with a gradual tapering off trend
expected from northwest to southeast Saturday afternoon into the
early evening. Easterly upslope flow Friday night into early
Saturday will turn more northeast to north on Saturday as the
inverted sfc trough passes through and exits our area to the east.
The WAA/frontogenesis induced heavier or more steady snowfall still
looks to occur during the overnight hours through about daybreak-mid
morning Saturday. Lighter snowfall will generally take hold the
remainder of the day before tapering off and ending by late afternoon
or early evening. There remains not much change in the overall
QPF/snowfall probabilities footprint across the forecast area. Given
the dynamics involved in this wave, parts of our area could be in
line to pick up at least a quarter of an inch of liquid precip.
Highest probabilities of seeing more than this amount range from 50-
80 percent on a line from the Mobridge to Faulkton to Huron. Lower
probs(20-50 percent) surround this area on both the north and east
side(Aberdeen/Watertown areas) and the the west and south
side(Pierre/I-90 corridor areas). Snowfall probabilities of seeing
more than 4 inches continue to highlight zones between the Missouri
and James Valleys or roughly from Edmunds County south through
Hyde/Hand and east through Spink and Clark Counties. These areas sit
at about a 70-90 percent chance of seeing more than 4 inches and
about a 50-70 percent chance of seeing more than 6 inches. As
mentioned earlier, a Winter Storm Watch has been issued for these
locations from mid morning Friday through late Saturday afternoon.
There will be some wind to accompany this storm system but nothing
comparable to our last clipper like system on Tuesday. Gusty winds
up to 30 mph will be possible Saturday afternoon across south
central SD. Some blowing and drifting along with reduced
visibility(especially during snowfall) will be possible through late
Saturday afternoon/early evening, but improvement expected after the
snowfall ends and winds diminish Saturday night.

A 1040mb sfc high pressure system is then set to build into the
region Saturday night into Sunday sending southward a reinforcing
shot of arctic air into our area that will persist into early next
week. This sfc high is then expected to shift east by Tuesday which
will promote a more southerly low level flow to take over only to be
followed by another frontal boundary passage that may deliver some
precipitation to parts of the area at the end of this period.
Daytime temperatures in the teens and low 20s on Saturday will take
a nose dive Saturday night falling into the single digits above and
below zero. A very cold end to the holiday weekend is expected with
daytime highs on Sunday only reaching the upper single digits above
zero to mid teens. Throwing in a little bit of wind(5-15 mph) will
produce wind chill values into the 15-20 below range. These much
below normal temperatures will prevail through the middle of next
week, even with a slow and slight warming trend expected. Daytime
temperatures in the 20s to low 30s may be possible by the end of
this period.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 515 AM CST Thu Nov 27 2025

Terminals KABR,KATY,KPIR,KMBG

Low clouds and visibilities will continue to cause MVFR/IFR
conditions this morning over KABR, KMBG, and KATY. The low clouds
will continue to cause IFR/MVFR conditions through most of the day
today. KPIR is the exception as it has and will continue to have VFR
conditions though the day.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Storm Watch from Friday morning through Saturday
     afternoon for SDZ010-017>019-036-037.

MN...None.
&&

$$

UPDATE...12
SHORT TERM...12
LONG TERM...Vipond
AVIATION...12