038
FXUS63 KABR 240711
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
211 AM CDT Thu Sep 24 2026

.KEY MESSAGES...

- Scattered rain showers and weak thunderstorms will continue this
morning with the last of the rain exiting the region by the midday.
There is a 60-95% chance to see a quarter of an inch of rain or more
along and east of the James River, with the highest chance along and
east of I29.

- Another round of rain arrives Friday afternoon into Saturday
morning. There is a 40-60% chance to see a quarter of an inch or
more through Saturday morning.

- Expect temperatures near normal for the next few days, with highs
in the upper 60s to low 70s. Signs point towards a cooldown next
week.

&&

.DISCUSSION...
Issued at 211 AM CDT Thu Sep 24 2026

As of 06Z, the shortwave is currently positioned over northwestern
SD through ND/Canada with winds out of southwest through 850mb and
southerly/southeasterly winds at the surface. With this flow lots of
moisture is being pulled in from the south and southwestern US (seen
on water vapor imagery) in thanks to a 30kt LLJ over much of the CWA
as the surface trough currently extends just west of the CWA. This
has led to better coverage and formation of scattered rain showers
tracking northeast along and just east of the Mo River with
additional rain moving in from southern SD/NE. 500 j/kg of MUCAPE
and 25-30kts of bulk shear is producing weak embedded thunderstorms
we well. Through 12Z CAMs really indicate this shortwave energy
induced rain across NE/KS continuing to merge with the rain over the
Northern Plains to produce additional development and better
coverage of the scattered rain, and potentially weak thunderstorms,
east of the James River into MN. The last of precip is forecast to
exit far eastern SD/MN by the midday or early afternoon as CAMs
overall agree on this. A few of the CAMS do indicate lingering
spotty showers possible Coteau eastward 18Z through tonight.
Probability of QPF (or additional QPF)>0.25" (starting at 06Z) is 60-
95% James Valley and eastward, highest along and east of I29. Prob
for a half inch is 60-80% along and east of I29. Any stronger rain
showers or storms could produce locally higher QPF.

Otherwise, dry air aloft moves in behind the system and will
continue to spread eastward across the CWA with the driest air along
and west of the MO River by this evening/overnight as the Northern
Plains remains under this broad ridge and mid level high moves in
over the region. Surface winds will be out of the southeast/east
over central SD and southeast over northeastern SD/MN. With ongoing
low level moisture and cloud cover hanging around, this could result
in low stratus/drizzle/fog late tonight through Friday morning as
NAM/EC soundings indicate this classic drizzle setup with some
omega at the surface to 850 and dry air aloft. So fog and drizzle
may need to be added in closer to time if confidence increases.

We continue with this shortwave train as more energy moves in from
the south combining with a stronger negatively tilted shortwave
moving in from the southwest (per an ongoing trough hanging over the
PacNW). This neg tilted shortwave will track northeast across the
region Friday through Saturday. Southeasterly flow at low levels
will pull in moisture resulting in another round of rain. As of now,
pops will increase south to north across the CWA Friday afternoon
and evening with the bulk of the precip occurring Friday night
through Saturday morning (mainly east of Mo River) with the help of
strengthening LLJ. Latest NBM pops range from 40-70%, highest James
Valley and eastward. Rain will diminish west to east through late
Saturday afternoon. Probability of 24 QPF>0.25 ending Saturday
evening is 40-60% James Valley and eastward. Still a bit of a
difference between models QPF wise with the 25-75th spread of 0.3 to
0.6", highest over eastern and southeastern CWA.

Dry conditions for Sunday but we will continue in this active weather
pattern as the trough that has been hanging out over the PacNW will
track northeast into Canada with another trough developing over the
western CONUS Monday and track eastward and over the central/southern
CONUS Tuesday/Wednesday. Still quite the difference between the
Clusters on location timing and intensity and its surface low that
is forecast to develop over the Northern Rockies and track across
the Northern Plains Monday/Tuesday bringing the return of rain.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1243 AM CDT Thu Sep 24 2026

Terminals KABR,KATY,KPIR,KMBG

VFR stratus conditions will kick off this TAF set but lowering
cigs will return MVFR/IFR cigs to KABR/KATY/KMBG terminals
through the early morning hours. Along with the lower ceilings
will come chances for -SHRAs/-TSRAs, especially for KABR/KATY
TAF sites through the pre-dawn hours. If the intensity of this
activity were to get heavy enough, MVFR vsbys will be possible.
Not much in the way of improvements in ceiling conditions are
expected at KABR/KATY through the remainder of this forecast
period. After MVFR cigs hang on through a portion of the morning
at KPIR/KMBG, VFR conditions are expected to return later this
afternoon into tonight. Southeast winds will remain gusty up to
25 kts at KABR/KATY through the afternoon while KPIR/KMBG
experiences lighter winds and a direction change to the west to
northwest later this morning.

&&

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

&&

$$

DISCUSSION...MMM
AVIATION...Vipond