567
FXUS63 KABR 190554
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
1254 AM CDT Fri Jun 19 2026

.KEY MESSAGES...

- North south band of light rain migrating east across the state
north of Highway 14 early this morning. Just a few hundredths of
rain.

- Late Saturday/Sunday widespread rainfall focused across central
South Dakota. 70% probability for Pierre precipitation > 1".

- Temperatures remain near to slightly below normal through next
week. Coolest day being Sunday at 10 to 20 degrees below normal.

&&

.DISCUSSION...
Issued at 1252 AM CDT Fri Jun 19 2026

North south band of light precipitation migrating across the
northern half of the CWA early this morning. Just seeing a few
hundredths of moisture and a wind shift to west northwest.

The upper pattern starts with a broad/shallow trough to the east and
northwest flow aloft. This shifts east, with a weak ridge aloft
migrating in from the west out ahead of a wave that crosses the
Northern Rockies late Saturday/Sunday.  Thats followed by another
northwest flow trough, another bump in the flow for late in the week.
This does two things for us: 1) keeping the mid/low levels cool:
700mb as cool as +2C to -2C Friday and as warm as +2 to +8C Sunday.
Forecast highs in the 70s. And 2) temperate dewpoints, from 40s to
as high as mid 50s.

Departing convection migrates east this morning, but in its wake,
limited/shallow instability is showing up in the BUFKIT profiles.
Could be some daytime driven storms along the eastern/southeastern
periphery of the CWA but more favoriable conditions exists to the
east. High pressure extends southeast out of Montana ie. mild
temperatures and low dewpoints Today.

The wave for late Saturday/Sunday features more synoptic driven mid
level moisture as opposed to surface based convective instability as
the source for precipitation. Mean NBM precipitation highlights
central/south central South Dakota with a mean peak of close to 2
inches and a 25th/75th range of between 0.75" to 2.25". Up across
the north central/northeast, the values are much lower with a mean
of about 0.75" for Mobridge, 0.25" for Aberdeen/Watertown and
nothing for west central Minnesota. Uncertainty in the exact track
means the northern tier is on the edge between higher amounts and
essentially nothing. This means the broader range for the 25th/75th
percentiles being nothing for the low end at
Mobridge/Aberdeen/Watertown etc, and a higher bound of 1.5" for
Mobridge and 0.5" Aberdeen/Watertown, though west central Minnesota
maintains an upper bound of just a few hundredths.

This main reason for the high range of outcomes in the northern
extent of rainfall is evident in NAM BUFKIT profiles, a dry subcloud
layer. This is due to high pressure to the north feeding drier air
into the system.

The next northwest flow shortwave that follows moves through late
Monday/early Tuesday. Environment here is again, skinny CAPE and
unidirectional flow, albeit not very strong.

See below for an update to the Aviation/06Z TAFS discussion...

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1252 AM CDT Fri Jun 19 2026

Terminals KABR,KATY,KPIR,KMBG

Band of light rain moving towards KABR and could also go through
KATY with a mid level deck AOA 10kft. Once that goes through, winds
shift to the northwest. Winds pick up to around 20 to 30kts out of
the northwest during the late morning/afternoon. VFR conditions
otherwise.

&&

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

&&

$$

DISCUSSION...07
AVIATION...07