Watertown, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

540
FXUS63 KABR 260633
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
133 AM CDT Sun Jul 26 2026

.KEY MESSAGES...

- Extreme Heat Warning for Today, with heat indices from around
  100 to as much as 110 degrees.

- There is a Slight Risk (2 of 5) for severe storms east of I-29
  late this evening. Just looking at an isolated/20% chance that
  a storm will develop.

- Western wildfire smoke may impact visibility across the
  Missouri  valley and points west as a weak system crosses the
  region.

- Less intense heat but temperatures still 5 to 15 degrees above
  normal through at least mid-week.

&&

.DISCUSSION...
Issued at 129 AM CDT Sun Jul 26 2026

Well the first thing we`ll really need to evaluate is the smoke
potential with all the activity across the west. A trough develops
across the western Dakotas later today, with a plume headed into
mainly western to central/north central South Dakota and potentially
having impacts to visibility. The HRRR shows less smoke moving in at
ground level across the east. Aloft, smoke continues but will be
most prominent Monday and is likely to have an impact on
temperatures.

Regarding the heat today, NBM dewpoints are still forecast close to
70. Looking deeper, the NBM still has a GEFS issue which is overly
mixy, and artificially weighing down dewpoints, while the EC and
Canadian ensembles picked up on the `well into 70s` dewpoints that we
ended up experiencing yesterday. EC members are a little lower
today, while the Canadian members are on par compared to Saturday.
Assuming a low bias in NBM dewpoints, and temperatures still maybe
just a few degrees too warm temperature-wise east river but on
target for the Missouri valley... there is enough evidence for an
upgrade to the Advisory to a Heat Warning.

The upper pattern remains stagnant through mid-week with the 4-
Corners high and a northwest flow regime east of the ridge axis that
persists along the WY/MT and Dakotas state line. The next plume of
moisture that pivots around  the high and into the Northern Plains
comes in late Monday/Tuesday timeframe. A wave coming in off the
Pacific eventually suppresses the high and gives us our next, best
chance for moisture Wednesday night/Thursday. Otherwise, peak heat
continues for now today, with some slight diminishment but still  5
to 15 degrees above normal for the first half of the work week.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1227 AM CDT Sun Jul 26 2026

Terminals KABR,KATY,KPIR,KMBG

Expect mainly VFR conditions through the period. The main
concern will be smoke that may bring visibility to MVFR levels
after 02Z Monday at MBG.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Extreme Heat Warning until 9 PM CDT /8 PM MDT/ this evening
     for SDZ003>011-015>023-033>037-045-048-051.
MN...Extreme Heat Warning until 9 PM CDT this evening for MNZ039-
     046.

&&

$$

DISCUSSION...07
AVIATION...06