Plankinton South Dakota Weather Forecast Discussion

411
FXUS63 KFSD 100920
AFDFSD
Area Forecast Discussion
National Weather Service Sioux Falls SD
420 AM CDT Fri Oct 10 2025
.KEY MESSAGES...
- Cooler today, but overall above normal temperatures will
  persist into this weekend. Increasing hints that we will
  transition to normal to a bit below normal temperatures next
  week.
- Rain chances increase (30-60%) late Saturday into Sunday with
  the passage of a cold front. Timing uncertainty of the frontal
  passage may lead to changes in which areas see the best chance
  of rain, so keep up to date with the latest forecast.
- Additional chances (around 20%) for rain are possible into
  parts of next week though details are uncertain and confidence
  is low.
&&
.DISCUSSION...
Issued at 413 AM CDT Fri Oct 10 2025
A dry cool front continues to move through northwest Iowa this
morning, leaving cooler temperatures and clearer skies in its
wake. Very patchy shallow fog has developed in areas where
winds were able to turn light, but expect any fog to burn off
quickly with sunrise. A dry, sunny, and pleasant day is in store
for our day today as high pressure settles over the Northern
Plains and winds lighten. Highs today will be mainly in the
mid-60s to low-70s with winds out of the north-northeast around
5-10 mph.
As the surface high drifts east of the area tonight, expect the
return of southeasterly winds and thus another warming trend into
the weekend. Looking off to our west, an upper-low and its attendant
trough will move into the Pacific Northwest and send a couple of
waves our way through the weekend. The first of these waves will
move in from eastern Rockies/central High Plains tonight, increasing
cloud cover from west to east across the area. A few showers will be
associated with this activity heading into tomorrow morning, but
soundings indicate that any raindrops will have to battle a fairly
deep dry layer of air, so most of this activity will struggle to
reach the ground.
Winds will pick up tomorrow as the low-level jet strengthens
through the day into tomorrow night, with gusts up to 25- 35 mph
(locally stronger). Temperature-wise tomorrow, the return of
southerly flow will be offset by extra cloud cover and thus
highs will be about the same as today (mid-60s to low-70s,
though less mid- 60s overall compared to today). Another upper-
wave moves into the area tomorrow evening into the night,
bringing another chance of some showers. There will be a little
less dry air to overcome this time as the southerly LLJ
strengthens and continues to bring in more moisture around 850
mb, but still expecting shower coverage to be fairly scattered
in nature at this time.
On Sunday, the aforementioned upper-low over the Pacific Northwest
will move into the Northern Plains, with a surface low moving across
North Dakota into southern Canada and its associated cold front
draped across the northern Plains into the central Plains moving
eastward. Warm air pools ahead of the front and so highs on Sunday
will be in the upper-70s to mid-80s. Showers and isolated storms
look to fire up ahead of the front, placing the better rain chances
along and east of I-29 at this time. However, the timing of the
frontal passage may change as we get closer to the event, which
could impact overall rain chances as some guidance indicates the
cold front passing through the area before showers/storms get going.
Instability looks to be quite weak, so only general thunder is
expected at this time. The cold front clears the area heading into
Monday morning, leading to cooler temperatures with highs in
the mid-50s to low-60s Monday and Tuesday. A couple of
additionalweak waves may keep some small rain chances in the
forecast into parts of next week, but confidence is low as many
details remain uncertain. Another warm-up may occur mid-week as
ridging aloft may build back in. Guidance diverges significantly
from there on the location and development of another big
upper- trough over the western US, which could eventually have
downstream effects into our area to end next week.
&&
.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1005 PM CDT Thu Oct 9 2025
A frontal boundary continues to slide southeast through the
region, gradually pushing mid-lvl clouds to the southeast with
it. Winds will gradually swing to the northwest and north
behind the front as skies remain clear.
VFR conditions are likely on Friday with a light to occasionally
breezy northerly wind.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.
&&
$$
DISCUSSION...Samet
AVIATION...Dux

NWS FSD Office Area Forecast Discussion