Watertown, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

894
FXUS63 KABR 242324 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
624 PM CDT Fri Jul 24 2026

.KEY MESSAGES...

- Marginal Risk (level 1 of 5) for isolated to scattered
  (20-30% chance) severe storms over north central SD this
  afternoon and move east this evening. The primary threats will
  be 1 inch hail and 60 to 70 mph wind gusts. These storms are
  most likely to be limited to the Highway 12 corridor and
  locations north.

- Increasing heat/humidity Saturday and Sunday. Heat Advisory in
  effect both days, with heat indices from 95 to 105 degrees.

- Marginal Risk (level 1 of 5) for strong to severe storms
  Saturday afternoon over portions of southwest and south
  central SD. Main threat would be wind gusts from 60 to 70 mph.

- Surface wildfire smoke may materialize across portions of
  northern SD Saturday afternoon, although concentrations
  appear to remain fairly low at this time.

&&

.UPDATE...
Issued at 617 PM CDT Fri Jul 24 2026

Updated discussion for the 00Z TAFs below.

&&

.DISCUSSION...
Issued at 145 PM CDT Fri Jul 24 2026

Stratocumulus deck has been stubborn to leave the southeast CWA
early this afternoon, but HRRR sounding trends suggest gradual
scattering out of these clouds into late afternoon. Increased sky
cover grids for a few more hours in this area to reflect "mostly
cloudy" wording until later in the afternoon.

Will continue to watch potential for strong/severe storms this
afternoon across ND into far northern SD. CAMs continue to be rather
scant in overall coverage, and will also be dealing with capping
issues this far south. MLCAPE values increase to around 2000 J/KG
along the surface boundary later this afternoon. DCAPE values rather
sporty from around 1400-1800 J/KG. So, any convection that manages
to fire and make it into the northern CWA is capable of gusty winds
perhaps over 60 mph. PoPs generally reflect 20-30% across the
northern CWA into the early evening hours.

Focus then shifts to the increasing heat/humidity this weekend as
warmer air aloft (+32 to +35C at 850mb) spreads eastward over the
Northern Plains. Highs look to soar into the 90s and low 100s, but
am slightly concerned about smoke and the potential NBM high bias
causing actual highs to be a couple degrees shy of forecast.
Nonetheless, it would still appear much of the CWA comes close, or
into low-end advisory criteria Saturday afternoon, as well as
Sunday. Went ahead and collaboration a 2-day Heat Advisory covering
both Saturday and Sunday`s expected heat indices from 95 to 105
across much of the CWA.

Speaking of smoke from earlier in the discussion, latest run of HRRR-
smoke does bring fairly high concentrations of smoke aloft tonight
and into the day Saturday. Whether or not it`s enough to hold
temperatures back a few degrees is yet to be seen. Latest visible
imagery shows appreciable thickness across southern Canada where
current HRRR-smoke output suggests around 100-175 mg/m^2.
Concentrations this high in the HRRR-smoke are generally confined to
ND and northern MN tonight through Saturday, so tough to say if we
see thickness enough to keep temps down slightly, which could also
factor into reaching heat advisory criteria or not. There are even
some indications there could be surface smoke to contend with (low
concentrations) over the northern CWA during the day Saturday, so
inserted/expanded mention of this in the grids/forecast.

It still appears there is potential (20-30%) for a few storms across
the high plains of western SD Saturday afternoon, possibly moving
into the western CWA late in the afternoon into early evening.
Soundings reveal most likely threat would be gusty winds in excess
of 60 mph. SPC Day 2 outlook still has Marginal Risk over the
southwest CWA to cover this.

Looking ahead further into the forecast, hot temperatures look to
stick around through much of the period, with inherited NBM highs
ranging from the upper 80s to upper 90s Sunday through Friday of
next week. Best opportunity for precipitation (30-50%) looks to be
Wednesday into Wednesday night with a passing system. NBM
probability for anything more than 0.50in is only around 20 percent
or less though.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 617 PM CDT Fri Jul 24 2026

Terminals KABR,KATY,KPIR,KMBG

Isolated to scattered thunderstorms are tracking east/southeast
across north central SD with a more robust cluster of storms
tracking southeast across ND. If these hold together could
impact KABR in the next couple of hours, so added in a prob30 to
show for this along with a viz drop to MVFR/IFR possible. Main
concern if these continue to be severe will be wind gusts of
60-70 mph. Will amend closer to time to update. Otherwise,
ongoing smoke both at the surface and aloft will overspread the
region behind a cold front. If thick enough, could see a drop in
visibility to MVFR at times. Otherwise, VFR conditions prevail.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Heat Advisory from 1 PM CDT /noon MDT/ Saturday to 9 PM CDT /8
    PM MDT/ Sunday for SDZ003>011-015>023-033>037-045-048-051.
MN...Heat Advisory from 1 PM Saturday to 9 PM CDT Sunday for MNZ039-
     046.

&&

$$

UPDATE...MMM
DISCUSSION...TMT
AVIATION...MMM