310
FXUS63 KABR 021925
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
225 PM CDT Sat Aug 2 2025

.KEY MESSAGES...

- Scattered showers and thunderstorms remain in the forecast
  through Monday. The slow-moving nature of thunderstorms tonight
  makes torrential heavy rainfall a threat, primarily over
  northeast South Dakota. There is a marginal risk (1 out of 5)
  for severe storms on Monday.

- Surface smoke from wildfires is expected to persist across much
  of the region heading into Sunday morning. By Sunday evening,
  considerable improvement in both smoke aloft and near the
  surface is expected. Monitor the latest from the EPA and state
  agencies, as there may be impacts for those sensitive to smoke.

&&

.DISCUSSION...
Issued at 224 PM CDT Sat Aug 2 2025

At 2 PM CDT, skies are mostly cloudy/smokey, and there is ongoing
near surface smoke reducing visibility to 4-7 miles. Winds are from
the south-southeast around 10 to 20 mph with gusts generally up to
30 mph. Temperatures are warming through the 60s and 70s.

Steering flow winds aloft point out upper level longwave trofs
holding both CONUS coasts, with a (cut-off) ridge of upper level
high pressure extending from the Dakotas all the way up into north
central Canada. A belt of westerlies aloft running from California
to southeast Kansas cuts through the upper level ridge, with the
remaining higher heights aloft extending down from the central high
plains down into the desert southwest. All that to say, the pattern
aloft is blocky, with little to no steering winds aloft over this
CWA. That means that this upper low circulation over the Dakotas is
stuck over the region for the next couple of days until better
steering flow winds move in as higher heights previously described
from Canada down to the desert southwest flatten/propagate east.
Models prog that to start happening Monday and continuing through
Thursday, at which point the west coast upper level longwave trof
will begin to move toward the intermountain west toward the end of
the forecast period.

Seeing less deep layer shear in the models for this
afternoon/tonight than what yesterday/last night had to work with.
No tornado risk today/tonight, and given the lack of notable
instability, not really a hail/wind threat this afternoon/tonight
either. Mainly just another scenario involving slow moving, heavy-
rain producing thunderstorms (wpc`s day 1 ERO marginal risk over
this CWA has been upgraded to a slight risk for excessive heavy
rain) heading into tonight. Thunderstorm potential this
afternoon/early evening is heavily dependent on the amount/duration
of daytime heating, and right now, it`s more cloudy than sunny over
the CWA, limiting heating/destabilization.

Models prog this very slow moving upper low to be nearing the
Minnesota border with the Dakotas by the end of peak heating on
Sunday. Again, similar set-up, just shifted appx 70-80 miles further
east than today.

An active weather pattern continues (ensemble qpf clusters
analysis), heading into the middle to latter part of the upcoming
week. Perhaps a little bit better shear/instability scenario and
better/stronger winds aloft will make for more organized
strong/severe storms potential heading into Monday and Tuesday. With
increased winds aloft and these southerly surface/PBL winds
continuing through the rest of the weekend, the latest RRFS model
output shows decreasing smoke (both aloft and near surface) starting
tonight and continuing through Sunday.

Per model progs and ensemble-based probabilities/850hpa temperature
anomalies, below normal temperatures persist Sunday, before the
warming trend begins on Monday and persists through Thursday. High
temperatures on Thursday are expected to range from the mid 80s to
the mid 90s throughout the region. The next synoptic-scale cold
front progged to actually clear the entire CWA appears to be
happening sometime between Thursday afternoon and Friday afternoon,
as ensembles guidance begins a modest cooling trend through the rest
of the forecast period.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1237 PM CDT Sat Aug 2 2025

Terminals KABR,KATY,KPIR,KMBG

Smoke (both aloft and near the surface) continues to hang around
this afternoon with visibilities generally around 4-7SM.
Improvement to VFR is possible again prior to 00Z. However, before
sunrise on Sunday, MVFR visibility in smoke is expected to return.
KPIR and KMBG should mix out their MVFR stratus cigs by 00Z this
evening. However, most of the terminals could be dealing with some
MVFR low clouds again by sunrise Sunday morning (KPIR currently
being the lone exception. Isolated/widely scattered intermittent
showers are ongoing across the region. An increase in showers areal
coverage, and the development of a few thunderstorms are expected
between 21Z this afternoon and 06Z tonight. The slow moving nature
of showers and thunderstorms will mean heavy rain is the main
threat.

&&

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

$$

DISCUSSION...10
AVIATION...10