456
FXUS63 KABR 200753
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
253 AM CDT Sun Sep 20 2026

.KEY MESSAGES...

- Low clouds will persist into Monday and may result in periods of
  reduced visibility along higher terrain.

- Steady showers move into central SD today and make it as far east
  as parts of the James and Big Sioux Valleys tonight. Rain tapers
  off from north to south on Monday.

- Temperatures will remain below seasonal normals the next few days
  before returning to near normal toward the middle of the week.

&&

.DISCUSSION...
Issued at 252 AM CDT Sun Sep 20 2026

Weak shortwave ridging aloft across eastern SD/NE will shift east
this morning as an upper low over western WY slowly meanders east
into parts of western SD and NE by the end of the day. Low stratus
and some patchy fog will be possible in some areas through the
morning. Increasing chances for steady showers will make their way
into central SD later this morning into the afternoon as that upper
low slowly shifts east. This rain is progged to slowly move east as
far as the James Valley and parts of the Big Sioux Valley tonight
into early Monday. This system will slowly move east along the SD/NE
border tonight through Monday. The rain will gradually taper off
from north to south on Monday. Rainfall amounts are expected to be
highest across parts of central and south central SD where between a
half inch and three-quarters of an inch will be possible today
through the end of the event on Monday. Temperatures will remain
below normal the next couple days as the low stratus persists
underneath this disturbance.

Weak ridging aloft will attempt to work into the region on Tuesday
but gets shunted more east into the western Great Lakes.
Nevertheless, the overcast skies should break giving way to more
sunshine and drier conditions. Temperatures will begin to modify
closer to normal. Even warmer conditions are expected mid to late
week as southwest flow aloft re-establishes itself across the
Northern Plains. With another passage of a shortwave trough through
the region Wednesday into Thursday the next round of showers and
thunderstorms are expected. By the end of the period, upper ridging
is expected which will help return drier conditions to the area
along with temperatures at or slightly above normal late in the week.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1225 AM CDT Sun Sep 20 2026

Terminals KABR,KATY,KPIR,KMBG

Mainly MVFR/IFR ceilings will continue through much of the TAF
period. The exception is KABR, which will continue to
experience VFR cigs at times per gaps in the lower clouds.
Patchy fog is expected to develop near daybreak at KABR/KATY,
with light rain moving into central SD (KPIR/KMBG) around and
after 11Z today.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.

&&

$$

DISCUSSION...Vipond
AVIATION...MMM