258
FXUS63 KFSD 301946
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
246 PM CDT Thu Jul 30 2026

.KEY MESSAGES...

- Thunderstorms should increase in coverage into tonight.
  Locally heavy rain, possibly as high as 4-5 inches, will be
  the main concern across the area. A secondary concern will be
  wind gusts to 65 mph and hail to the size of quarters mainly
  in south-central South Dakota.

- While many locations will receive a beneficial half an inch to
  two inches of rainfall, the higher amounts could lead to
  localized flash flooding in urban and flood prone areas.

- Showers will linger into the day on Friday, with increasing
  winds through Friday morning. Winds will gust to around 35 mph
  at times, though isolated pockets of gusts pushing 45 mph
  can`t be ruled out Friday afternoon east of I-29.

- Dry conditions and seasonable temperatures return for the
  weekend. For next week, shower and storms chances will return
  Monday night into Tuesday.

&&

.DISCUSSION...
Issued at 229 PM CDT Thu Jul 30 2026

Scattered showers and storms are moving across areas mainly
near and east of the James River this afternoon, with some
clearing occurring behind this activity. This should allow for
greater destabilization in south-central South Dakota this
afternoon and thus have issued a Severe Thunderstorm Watch for
Brule, Gregory, and Charles Mix Counties. Damaging winds to 65
mph and quarter sized hail are the main threats locally through
the early evening hours. The greater severe weather risks looks
to be south and west of our area where the better instability
lies, but still be sure to remain weather aware. Elsewhere, the
environment has been pretty worked over and thus severe weather
is less likely. The one exception is over southwest Minnesota
where we`ve been able to warm to the low to middle 80s out ahead
of this early afternoon activity. However, with the current
rain and clouds moving in and growing increasingly thicker in
those areas, the threat for severe weather is diminishing there
as well. There`s also some clearing over north-central South
Dakota, so this will be another area to watch for storm
development, with any activity there moving east-southeast
through the evening into tonight.

Heading into the night, the main wave will close off into an upper
level low, with a surface low developing east of I-29 by daybreak
Friday. This will all combine to keep rain and some storms in the
forecast tonight through Friday morning and potentially as late as
Friday afternoon near and east of I-29 as moisture wraps around the
low. Any severe threat will greatly diminish after midnight, so this
will transition to mostly a heavy rain threat as showers and storms
will continue to push through the area. This could lead to localized
flash flooding primarily in urban and flood prone areas, so be sure
to remain weather aware. For the good majority of the area though,
this should be beneficial rainfall, with additional totals generally
between a half an inch to two inches through Friday afternoon.
Locally higher pockets of 4+ inches remain possible, but that will
be for areas that see multiple thunderstorms move over that same
area. With recent dryness, those rainfall totals won`t be much of a
concern for rural areas. But urban areas could see some flash
flooding with that kind of rainfall, so that will be the main
concern tonight. Another thing to note is that the aforementioned
surface low will be deepening over the area, so it will be a
bit breezy on Friday, with gusts to around 35 mph possible.
Isolated pockets of 40+ mph wind gusts can`t be ruled out mainly
east of I-29 Friday afternoon, but doesn`t look like it will be
widespread enough to warrant wind headlines at this time.

We`ll dry things out heading into Friday night, and depending on how
quickly clouds clear out, we could see widespread lows in the
50s by Saturday morning! If clouds take a little bit longer,
we`ll still likely see some 50s west of I-29, it`s just that
places east of there where clouds clear the latest may only drop
to the lower 60s. So still much cooler than we have been! Dry
and sunny conditions will be in store for the weekend, with a
pleasant Saturday expected with highs only in the upper 70s to
lower 80s across most of the area. Southerly flow returns on
Sunday, making for it to be a little hotter, though not nearly
as hot as it has been. Only south-central South Dakota has a
shot of reaching 90 degrees on Sunday, but heat indices there
will likely not stray too far from the air temperature. After
Friday, our next chance of appreciable rain/storms will be
Monday night into Tuesday as a cold front moves through the
area. Not a lot of time to look into details given the focus on
today and tonight`s forecast, but it does look like there will
be enough instability and shear to at least have some strong to
severe thunderstorm risk, though details remain low. It does
look likely though that another round of cooler air will filter
in behind this front, making for an overall pleasant first week
of August.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1257 PM CDT Thu Jul 30 2026

Scattered to numerous showers and storms are expected to
continue and progress east-southeast through the afternoon and into
the overnight hours. An isolated strong to severe storm is possible
with this activity especially this evening, with wind gusts to
around 50 kts the main threat along with heavy rainfall. Showers and
storms will start to become more scattered to isolated in nature by
early Friday morning as moisture wraps around a deepening low
pressure system. This will also bring MVFR to IFR stratus along with
it heading into Friday morning.

Winds will be mainly out of the southeast through the remainder of
the afternoon, gradually turning more to the northwest and then
north/northeast tonight into Friday morning as a low pressure system
swings across the area from northwest to southeast. This deepening
system will also bring breezier conditions to the area Friday
morning with gusts up to around 30 kts possible starting after
sunrise Friday morning.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.

&&

$$

DISCUSSION...Samet
AVIATION...Samet