690
FXUS63 KABR 201522 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1022 AM CDT Tue Oct 20 2026

.KEY MESSAGES...

- Temperatures today and Wednesday will be 10-20 degrees warmer
  than  normal, with highs in the upper 60s to mid 70s. Then
  there is the potential for temperatures to be 15-25 degrees
  above normal Thursday and Friday.

- Dry conditions continue through Thursday with rain chances
  (30-50%) potentially returning Friday night into Saturday.
  Low confidence in exact track and of the system along with
  estimated rainfall amounts at this time.

&&

.UPDATE...
Issued at 1011 AM CDT Tue Oct 20 2026

Clear skies and dry weather continue with current temps in the
upper 40s to the lower 50s, dewpoints in the 40s, and winds out
of the south/southeast between 5-15 mph. Kept with the trend
and blended in HRRR to lower dewpoints as NBM keeps them a bit
high compared to REFS/HRRR with overall dewpoints through the
afternoon in the 40s to around 50. Even with return flow, drier
air continues to the south of the region so not much moisture
being pulled northward. Also continued the trend of NBM90th for
temps. Forecast remains on track.

.UPDATE...
Issued at 610 AM CDT Tue Oct 20 2026

See below for an aviation forecast discussion for the 12Z TAFs.

&&

.DISCUSSION...
Issued at 122 AM CDT Tue Oct 20 2026

An upper-level ridge has moved over SD and it will stick around over
the areas through Thursday. It is helping to support southerly winds
moving warm temperatures into central and northeastern SD.
Temperatures will be between 10-20 degrees warmer than normal today
and Wednesday, with highs in the upper 60s to mid 70s. There is a
small shortwave aloft that will move along the contours of the
ridge. This will push a weak low pressure and front through central
and northeastern SD tonight and Wednesday morning. Luckily, there is
drier air over SD, which will stop the front from developing
precipitation. The only thing one would notice from the front moving
through will be a change in the wind direction. As dry air sticks
around today and on Wednesday, there will be sunny to mostly sunny
skies.

Things will start to change Thursday, as an upper-level trough helps
to push a surface low pressure from NV to the northeast over MT and
then Saskatchewan. While this low pressure will not move over SD, it
will have a couple of fronts that move over the state. Additionally,
it will cause the pressure gradient to tighten over SD as the low
pressure interacts with a strong high pressure over the Great Lakes.
This tight pressure gradient will start to strengthen the winds
aloft that will then mix down to the surface, causing strong
southerly wind gusts to occur. The strongest of these wind gusts
will occur Friday afternoon through Saturday morning. Ensembles show
that there is a 30-50% chance for the winds to gust up to and over
than 45 mph. These winds will need to be watched in upcoming model
runs to see if a wind headline might be needed. These southerly
winds will help to push more warm air into SD, which will increase
the temperatures. The temperatures will be 15-25 degrees warmer than
normal Thursday and Friday, with highs getting up into the 70s to
low 80s. The warmest temperatures will be over south central SD,
with a 40-60% chance that they get over 80 degrees.

The winds are not the only thing that will need to be watched in
upcoming model runs. While this low pressure system will bring our
next chance for rain, the models still vary the timing, track, and
amounts. The models agree that the warm front for this low will be
moving over SD Thursday and stay over the state into Friday. The
models vary when and where rain and potentially storms start to
develop along this front and how quickly the front (and its rain)
moves out. The models then vary when the cold front moves in, when
the rain might develop along it, as well as how long the front and
rain stays over portions of northeastern SD Saturday into Sunday.
There is still a 30-50% chance of precipitation occurring a some
point Friday and at sometime on Saturday, there is just lower
confidence on when and where.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 610 AM CDT Tue Oct 20 2026

Terminals KABR,KATY,KPIR,KMBG

Good VFR conditions are forecast throughout the TAF valid
period.

&&

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

&&

$$

UPDATE...MMM
DISCUSSION...12
AVIATION...10