823
FXUS63 KABR 210041 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
741 PM CDT Thu Aug 20 2026

.KEY MESSAGES...

- Mainly dry conditions will continue through next Wednesday.
  However, there is a 30-60% chance for showers and
  thunderstorms during the day Sunday over central SD, and
  Sunday night across much of central to northeastern SD.

&&

.UPDATE...
Issued at 738 PM CDT Thu Aug 20 2026

Severe convection threat is done. Cold front cleared the CWA
about an hour and a half ago. Now waiting to see how long it
will take surface high pressure up north to work its way down
into the northern plains. Current gridded forecast package is in
fine shape. No changes planned to the tonight period.

UPDATE Issued at 616 PM CDT Thu Aug 20 2026

See below for an aviation forecast discussion for the 00Z TAFs.

&&

.DISCUSSION...
Issued at 215 PM CDT Thu Aug 20 2026

Low pressure centered over northwestern MN at 18Z today is draping a
cold front across southeastern ND and from around Aberdeen to just
east of Pierre. While winds are light and variable near the boundary,
they have been out of the west to southwest with gusts 25-37mph over
portions of east central SD (mainly near the east of I-29) early
this afternoon, and gusting out of the northwest 20-25kts behind the
front. We`ll continue to watch this front as it shifts east, with
the potential for thunderstorm initiation over east central SD and
east mid to late afternoon. The highest potential for showers and
storms over our eastern most counties still looks to be around 5-8
PM (22-01Z). We`ll continue to monitor the latest trends for this
afternoon as these storms could quickly produce hail or strong
winds. The highest potential for development remains to our south
and east.

A milky sky remains from smoke streaming in from the northwest. The
EPA/USFS fire.airnow.gov site has shown degrading air quality over
portions of central SD. While most upstream locations over MT have
improved to over 6SM visibility, we still have about a 2-3 hour
period over portions of central SD where vis may briefly fall to
around 6SM before improving.

The cold front will sink to our southeast by 03Z as the surface low
shifts across central to northeastern MN. 1020mb high pressure
currently over southwestern Canada will shift across Manitoba Friday
as a weak surface trough/secondary cold front clips our north and
northeastern counties. While the forecast is currently dry, we will
need to monitor the latest trends as a 20% chance of showers or an
isolated thunderstorm isn`t completely out of the question. An hour
or showers or thunderstorms may also move across our far southern
counties as a weak wave/cold front move across mainly northern NE.

Expect the slow moving surface high to push across Manitoba and ND
Saturday with the trough in place across SD, before moving into MN
Saturday evening into Sunday. The main result for our area, with a
lee trough setting up to our west will be increasing winds out of the
southeast. There is a 40-60% chance of wind gusts over 35 mph Sunday
mainly west of the MO River (highest chances west of Mobridge and
south of Pierre). Wet weather returns Sunday, with a 30-60% chance
of showers and thunderstorms Sunday into Sunday night. Some of the
NCAR Medium-range Real-time AI NWP convective hazard forecasts
continue to highlight 12Z Monday-12Z Tuesday as our next potential
for strong to severe storms aligning with the next surface low
crossing southern Canada and dragging a cold front across our area.
There`s enough differences in the solutions to only have around a
20% chance of showers/storms at this time, but it will be another
time period to watch. There are some significant differences in the
overall 500mb pattern as we move into Thursday of next week, with a
33% chance of the dominant ridge to our west moving overhead.
However, more of a northwesterly flow pattern looks to be more
likely with the ridge staying west. No large-scale pattern changes
are anticipated.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 616 PM CDT Thu Aug 20 2026

Terminals KABR,KATY,KPIR,KMBG

Mainly VFR conditions are expected over the next 24 hours.

&&

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

&&

$$

UPDATE...10
DISCUSSION...06
AVIATION...10