798
FXUS63 KABR 311725 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1225 PM CDT Sun Aug 31 2025

.KEY MESSAGES...

- Showers and weak thunderstorms will continue through the
  weekend. Severe weather is not expected with this system.
  Heavier rain or stationary storms may also pose an isolated
  flooding threat.

- A cold front will move through on Tuesday, with a 20 to 40
  percent chance of rain. The remainder of the week is expected
  to stay dry.

- Below normal temperatures are expected for mid week. Highs will
  be in the upper 50s to mid 60s, 10 to 20 degrees below normal.
  Low temperatures Thursday morning may dip into the upper 30s.

&&

.UPDATE...
Issued at 1007 AM CDT Sun Aug 31 2025

Allowed the dense fog advisory to expire this morning as
visibilities either have already or are improving across the
region.

&&

.DISCUSSION...
Issued at 238 AM CDT Sun Aug 31 2025

Once again showers linger over central South Dakota this morning,
but the bigger concern at the moment is fog over northeastern South
Dakota. As of ~08Z this morning, visibility reductions down to 1
mile have been observed, but existing fog remains patchy for the
time being. Coverage is expected to expand as sunrise approaches,
and visibility may get down to a quarter of a mile at times.
Therefore, a Dense Fog Advisory has been issued for Brown/Spink
counties and east, in addition to McPherson and Edmunds counties.

Low pressure center to the south will continue to progress eastward
today, continuing scattered showers to weak thunderstorms through
the afternoon and evening today. Once again the focus area will be
over central South Dakota. Parts of central South Dakota, namely
Stanley county, have seen a decent amount of rain over the past
couple of days, and soils have become saturated. Even in those
areas, the threat of flooding is offset a bit by rainfall rates
remaining low. However, the area could see another inch of rain over
the course of the next 24 hours, with locally higher amounts
possible. The good news is that the highest rainfall totals are
forecast to be a bit further east than where the saturated soils
are, more into Lyman/Buffalo/Hyde/Hand counties.

By Tuesday, a cold front is expected to move across the forecast
area, bringing the next chances for storms. Main threat area will be
across northeastern South Dakota into western Minnesota, where a
plume of 1000-2000 J/kg of surface based CAPE will be available,
along with modest shear of 20-30 knots. This will create what will
most likely be an isolated severe threat Tuesday. Wind is currently
the main expected threat, given dry air aloft, strong low-level
lapse rates, and upwards of 1000 J/kg of DCAPE in the area. Hail
could also be a threat, although would prefer to see higher MUCAPE
and stronger mid-levels lapse rates when looking for severe hail
potential.

Behind this front, the forecast area will be under strong northerly
flow aloft due to a strong trough digging in over the eastern CONUS.
This cold air advection will bring high temperatures down into the
60s for Wednesday and Thursday, 10 to 20 degrees below normal for
early September. Cold air advection may weaken with a slight
progression of the trough eastward by the weekend, so temperatures
may warm up closer to climatological normal by the end of the
forecast period.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1223 PM CDT Sun Aug 31 2025

Terminals KABR,KATY,KPIR,KMBG

A mix of VFR and MVFR cigs continues across the region today
through Monday morning. Additional showers and thunderstorms are
expected to develop again this afternoon in the evening, but
confidence is too low in determining location to add to tafs yet.
Fog will be possible again in areas where clouds scatter out
Monday morning.

&&

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

$$

UPDATE...20
DISCUSSION...BC
AVIATION...20