506
FXUS63 KABR 190905 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
405 AM CDT Sat Sep 19 2026

.KEY MESSAGES...

- Low clouds, fog and light drizzle will persist through the
  morning hours before improving in most locations. However, the
  Prairie Coteau and I-29 corridor will see the low stratus and
  patchy fog continue into the afternoon.

- Light showers will be possible this afternoon across central SD
  before more widespread steadier showers move in tonight and
  Sunday as far east at the James Valley before tapering off to the
  south on Monday.

- Temperatures will remain below seasonal normals the next
  several days before returning to near normal readings the
  latter half of next week.

&&

.UPDATE...
Issued at 402 AM CDT Sat Sep 19 2026

Issued a Dense Fog Advisory for counties along and east of the
Missouri River and counties over and east of the Sisseton Hills
until 15Z. Webcams, especially along I90, indicate the fog
becoming thicker as well as more patchy, but dense, over
portions of central SD.

&&

.DISCUSSION...
Issued at 227 AM CDT Sat Sep 19 2026

Low stratus, fog and light patchy drizzle continue early this
morning across parts of the forecast area. The areas that seem to be
the hardest hit are across northeast SD and the Prairie Coteau
region where sfc obs and area webcams confirm the lower visibilities
due to the fog and the drizzle. May need to consider a statement or
a headline in the near future if conditions continue to worsen.
Elsewhere, the fog and light drizzle are more patchy across west
central MN as well as areas along and west of the James Valley. By
mid to late morning, the fog and lower visibilities will improve
across central and parts of northeast SD and west central MN.
However, would anticipate the low stratus and patchy fog to persist
across the Prairie Coteau and the I-29 corridor into the afternoon.
Visibilities should improve by then with the possible exception of
the Summit area.

Sfc analysis indicates a couple areas of low pressure within the
region. The first one is located around Sioux City, IA and was the
main culprit for our rain and drizzle on Friday. This system is
progged to continue its trek south and east and away from our area.
The second low pressure system is located in northeast WY around
Gillette. It had been aiding some late evening showers and
thunderstorms across western SD and the Black Hills region. That
activity has either fizzled as it crossed through the northern Hills
or dived southeast into NE where it has persisted. Weak shortwave
ridging is expected across parts of the central and eastern Dakotas
today which should help to keep most zones dry. Low level northeast
flow should effectively maintain overcast skies underneath this
ridging. Cooler than normal temps, mainly in the 60s are expected
through the afternoon. An upper level low currently sits across the
Great Basin. A shortwave trough rotating around this system will
traverse northeast across WY into western SD today. This will
provide the energy needed to generate more scattered showers across
western SD. Some of these light showers could work into central
sections of SD this afternoon. An increasing chance for more
widespread precipitation is expected by Saturday evening into Sunday
across the western half of SD as the upper level low rotates through
WY tonight and into western SD and the NE Panhandle Sunday
afternoon into early Monday. Rain chances get about as far east the
James Valley late Sunday into early Monday before all the activity
shifts south as the upper low slides south and east into NE on
Monday and Monday night.

Guidance progs indicate that by late Monday into Tuesday we`ll see a
break from the precipitation has upper ridging briefly builds
overhead. This may be our first widespread opportunity to see a
break in the cloud cover. Southwest flow aloft will resume by
Wednesday into Thursday. Another shortwave trough is expected to
track northeast into parts of the Northern Plains on Wednesday into
Thursday. This system will result in another chance for showers.
Temperatures will begin to modify by this time frame with readings
climbing back closer to late September normals. After the upper wave
passes through by the end of the week, upper ridging is expected
which will lead to a drier and warmer trend for the area.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1213 AM CDT Sat Sep 19 2026

Terminals KABR,KATY,KPIR,KMBG

Low clouds, fog, and drizzle will remain in place across the
region through the afternoon. CIGs are a mix of MVFR/IFR, but
are forecast to become predominately IFR through the overnight
into Saturday morning. Areas of FG/BR and -DZ/DZ will also be
across the region, with VSBY dropping potentially to IFR/LIFR
at times. KATY stands the best chance to see IFR/LIFR VSBY.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Dense Fog Advisory until 10 AM CDT this morning for SDZ004-005-
     007>011-016-017-021-023-034>037-048-051.
MN...None.

&&

$$

UPDATE...MMM
DISCUSSION...Vipond
AVIATION...MMM