871
FXUS63 KABR 271902
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
202 PM CDT Mon Jul 27 2026

.KEY MESSAGES...

- Showers and thunderstorms moving into central SD late this
  afternoon into early evening. Marginal Risk (level 1 of 5) for
  severe storms, with main threat being strong wind gusts from
  60 to 75 mph.

- Western wildfire smoke may impact visibility at times across the
  region through Tuesday evening.

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

&&

.DISCUSSION...
Issued at 202 PM CDT Mon Jul 27 2026

Have some smoke aloft over the region as shown by CIRA Geocolor
imagery. Not much impact at the surface though, as much of the
region is P6SM visibility. Latest run of HRRR-smoke continues to
show moderate concentrations of smoke aloft and at the surface
through Tuesday evening, so continued mention of it in the
grids/forecast.

Temperatures this afternoon are warming through the upper 80s to
upper 90s. Latest look at heat indices shows everyone under 100
degrees, which was expected. Although, there will likely be a few
areas at 100 or even a couple ticks above by later this afternoon.
Areal coverage won`t be widespread enough to warrant any headlines.
Still a couple more days of the widespread 90s Tuesday and
Wednesday, before a slight cooldown to where more 80s show up for
highs by the last half of the week.

Main concern for later this afternoon into early evening is the
increasing coverage of showers/storms expected across western SD and
eventually into central SD. Radars upstream show activity moving out
of northeast WY/southeast MT and into far western SD. CAMs continue
to show development over the next few hours, especially the HRRR.
Opted to blend in some ECAM feel to PoPs this evening/tonight to
increase things just a little above that of NBM - better matching
HRRR trends. DCAPE values look to be around 1500 J/KG once again, so
strong wind gusts/outflows is the primary threat, with gusts perhaps
up to 70-75 mph.

Latest run of PoPs in the extended period shows precipitation
chances as high as 60-80 percent for Thursday/Thursday night.
GEFS/ENS/GEPS mean MSLP and mean 10m wind speeds/direction all show
a rather well defined surface boundary/trough moving across the CWA
during that time. ENS/GEPS mean dewpoints Thursday out ahead of the
frontal boundary show readings up around 70 degrees with PWATS on
the order of 1.80in to 1.90in. So, it would be safe to say we likely
develop some instability out ahead of the surface trough. ML severe
potential output showing some lower end probabilities for Thursday
into Thursday night. 75th percentile 24-hr precipitation off the
Grand Ensemble showing as much as 0.75in rainfall or higher.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1233 PM CDT Mon Jul 27 2026

Terminals KABR,KATY,KPIR,KMBG

Low concentration wildfire smoke (FU) at the surface this
afternoon, although most VSBY across the region is P6SM as of
18Z, so will continue with this trend until the evening when
VSBY may drop to around 6SM or lower. Also, last evening the
smoke aloft was think enough to generate a ceiling around 4500ft
at times, so opted to include mention of this in the TAFs as
well as we continue to be affected by smoke aloft through the
forecast period.

Will also be watching potential for TSRA across central SD by
early evening. Used PROB30 to handle this for the time being,
but could go TEMPO by later this afternoon as coverage may be
great enough to do this. Stronger storms are possible, with
strong surface wind gusts over 50 knots possible.

&&

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

&&

$$

DISCUSSION...TMT
AVIATION...TMT