050
FXUS63 KABR 210705
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
205 AM CDT Thu May 21 2026

.KEY MESSAGES...

- There is a 50-80 percent chance of 1/2 inch or more rainfall
occurring Friday into Friday night.

- Turning much warmer Sunday through next week, around 10 to 20
degrees above normal, with highs in the 80s to near 90.

&&

.DISCUSSION...
Issued at 205 AM CDT Thu May 21 2026

Weak mid level warm advection and subtle shortwave responsible for
light showers and sprinkles this am, which will lift northeast.
Otherwise we maintain a gradient with winds out of the south
gusting to 20 to 35 mph.

As for the wave Friday, timing is late tonight west river with some
convective nature but really just skinny CAPE in modest shear, which
weakens with loss of daytime heating. Some of that might leak into
the Missouri valley before dissipating. After 06Z a more
consolidated (24 hours ago it was 2) negatively tilted wave lifts up
across the area. CAMS take most of the day Friday to lift this
system up across the CWA and it may take the northeast until early
Saturday before everything has lifted north. The 25th percentile is
around 1/4 inch west river to 1/2 inch in the northeast while the
75th is closer to 1 inch so still a bit of range. Just some skinny
or shallow CAPE depending on model and location, so overall
assessment is mainly just rain/showers with little thunder.

Thereafter, there is a secondary wave aloft 12Z Saturday overhead.
This, and daytime heating may lead to additional light shower
activity. NBM is dry at this time, something to watch.

We have brief zonal flow overhead/upstream for Sunday/early Monday,
with flow becoming southwesterly aloft as a trough deepens across
the Pacific Northwest. This increasing heights and temperatures aloft
translates to warmer conditions for Sunday - Thursday. 700mb
temperatures increase to +6 to +10C, about a standard deviation
above climo. High temperatures that timeframe still 10 to 20F above
climo.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1223 AM CDT Thu May 21 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will continue over the next 24 hours. Gusts of
20-30kts can be expected from 14Z through the daytime hours,
lightest at ATY.

&&

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

&&

$$

DISCUSSION...07
AVIATION...06