089
FXUS63 KABR 231848
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
148 PM CDT Sat May 23 2026

.KEY MESSAGES...

- Warming trend in place through mid-week, with temperatures
  persistently above average from Sunday to the end of the 7-day
  forecast. Highs range in the upper 70s to upper 80s
  throughout the period. Monday and Tuesday could see highs
  reaching or exceeding the 90F degree mark (15 to 20 degrees
  above normal) in some places.

- Daily isolated to scattered thunderstorm chances (20-40
  percent chances) may be taking shape as early as Wednesday of
  this upcoming week, persisting through Saturday.

&&

.DISCUSSION...
Issued at 146 PM CDT Sat May 23 2026

At 1 PM CDT, skies are partly to mostly sunny and temperatures range
from the upper 50s to the lower 70s on a northwest breeze up to 10
mph with gusts up to around 20 mph.

Surface high pressure shifts east of the CWA this evening, allowing
for return flow south-southeasterly winds to establish. In this
developing set up, it appears there could be some isolated/scattered
convection developing by the early evening hours and persisting
overnight, thanks to the formation of a low level jet nosing up into
southern South Dakota. But, this CWA is expected to miss out on
convection (staying south/southeast of the CWA). A similar set up
should generate another round of limited coverage convection Sunday
evening/overnight.

While this is going on, mid/upper level heights are rising as an
upper level ridge builds into the Dakotas Monday/Tuesday. Models
have been consistent on producing a blocky/split flow pattern by the
middle of this upcoming week. The details have been less than
pristine, but still seeing a closed upper low/trough over the
Rockies and a downstream closed or becoming dynamically unstable
upper high/ridge across the upper midwest/western Great Lakes
heading into Wednesday and lasting all the way to Saturday before
the ridging wins out and the western CONUS upper troughing
decays/gets pushed off to the north and northeast in time. During
the trough/ridge period from Tuesday night through Saturday,
abundant amounts of low level moisture are able to be transported up
into this region (favorable set-up for it), setting the table with
plentiful instability for daily (daytime heating-driven) convective
chances, where-ever the local-scale best sources of low level
forcing/focus end up being. Mentioned a couple of days ago, this is
not a great set up for severe weather, as adequate deep layer shear
for severe thunderstorms is expected to be limited. Pulse-type to
multi-cell type afternoon through late evening convection would
probably be the norm during the Wednesday to Saturday timeframe. The
Ensemble Clusters QPF Analysis reveals measurable precipitation over
the CWA between Wednesday night/Thursday and Friday night/Saturday.

Having doubts about seeing 90s early this upcoming week with the
ECMWF Ensemble and its deterministic/control model continuing to
abstain from progging 925hpa and 850hpa temperatures as warm as what
the GFS/Canadian camps of model systems are showcasing. Doubtless it
will be warmer than climo normal for just about the entire 7-day
period. Additionally, green-up tends to insulate against higher-end
heating and current winds for Monday and Tuesday are forecast to be
between ~150-180 degrees for direction, which is a more difficult
wind direction to accomplish higher-end mixing/heating than what a
westerly component wind can do. NAEFS vs. ENS S.A. Ensemble Table
850hpa standardized anomalies speak to this issue, too.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1217 PM CDT Sat May 23 2026

Terminals KABR,KATY,KPIR,KMBG

Expect good VFR to prevail over the next 24 hours.

&&

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

&&

$$

DISCUSSION...10
AVIATION...10