369
FXUS63 KABR 291943
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
243 PM CDT Tue Sep 29 2026

.KEY MESSAGES...

- Patchy to areas of fog will develop overnight, with visibility
down to around 2 miles or less mainly east of the James River.

- High temperatures Thursday and Friday will be 5 to 8 degrees below
normal for this time of year.

- There is a 20-40% chance of light rain Saturday, mainly east of
the MO River.

&&

.DISCUSSION...
Issued at 243 PM CDT Tue Sep 29 2026

Slightly drier air is slowly working into the area behind a cold
front set up across our eastern counties at 19Z. Lingering light
rain has all but ended over our far eastern counties. Instead of RH
value sin the 80+ percent range, they are down into the 60-70%
ranges over north central SD west of the MO River this afternoon.

Light winds and lingering moisture overnight will result in fog
potentially developing, particularly over east central SD. There is
some uncertainty, but if fog does develop it will be dense with
headlines likely needed for a few counties. The ECMWF ENS visibility
meteogram page shows a 30% chance of visibility of 0.2 miles or less
at Watertown. Northwest of Watertown shows less of a chance of fog
developing.

An additional low over northern Alberta Canada will cross into
central Canada and drag a cold front along the ND/SD border
Wednesday morning/early afternoon. This boundary will continue to
sink southeast across the forecast area Wednesday afternoon/evening.
This will bring a temperature change down to slightly below normal
temperatures for highs starting Thursday. High temperatures Thursday
and Friday will be 5 to 8 degrees below normal for this time of
year. There is also a  30% chance of showers over central SD
Thursday night. Dry weather will again quickly take hold.There is a
20-40% chance of light rain Saturday, mainly east of the MO River.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1240 PM CDT Tue Sep 29 2026

Terminals KABR,KATY,KPIR,KMBG

While the western third of SD is mostly sunny, MVFR to high end
IFR conditions continue. Expect improving conditions with a
return to VFR ceilings at PIR/MBG by 22Z, and by around 23Z at
ATY. There is the potential that the clouds could hang on an
hour or so longer at ATY. Fog will be a concern at both ABR and
ATY overnight, with a return of MVFR to potentially IFR or even
LIFR. The highest chance of IFR conditions will be 10-14Z
Wednesday at ATY. Otherwise, expect VFR conditions to be at all
locations by 16Z Wednesday.

&&

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

&&

$$

DISCUSSION...06
AVIATION...06