197
FXUS63 KFSD 061652
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
1152 AM CDT Mon Oct 6 2025

.KEY MESSAGES...

- A few lingering sprinkles to light showers continue today,
  through measurable rainfall will be very minimal.

- Near to below seasonal temperatures make a brief appearance
  today, coolest south toward Sioux City-Storm Lake. A gradual
  warming trend is expected through the rest of the week, with
  moderate (50-70%) probabilities of highs back above 80F next
  weekend.

- A mostly dry week is ahead with just a low (20%) chance of
  rain east of I-29 on Thursday.

&&

.DISCUSSION...
Issued at 210 AM CDT Mon Oct 6 2025

This week will start off feeling much more like a typical early
October, with temperatures much cooler than late last week. The
area will be under the influence of a broad trough extending
from central Canada/Hudson Bay, through the northern Plains and
into the Desert Southwest. A subtle wave sliding northeast along
a mid-level frontal boundary will spread scattered light showers
into the southern portions of our forecast area today. Spotty
sprinkles or light showers may drift as far north as the I-90
corridor through midday-early afternoon, but most of the rain
should be confined to areas south of Yankton SD to Spencer IA.
With the surface front now well south across Kansas, northwest
Missouri and southeast Iowa, moisture will be somewhat limited
below the mid-level clouds (6-8kft AGL). As such, rainfall will
be on the light side with the better (30-40%) probability of
exceeding 0.10" confined to areas southeast of a Sioux City to
Storm Lake line. A few hundredths at best for most areas that
see rain, though.

Cloud cover will be more abundant even north of the rain,
though, and this combined with the overall cooler air mass will
bring us at least one Fall-like day in terms of temperatures.
Coolest readings will be found in our far southeast with the
clouds/rain persisting well into the afternoon. These areas
should struggle to reach 60F, with some areas perhaps holding
in the mid 50s. Farther north where rain will end earlier and
clouds break up in the afternoon, temperatures should rebound
into the lower 60s.

Cool high pressure will bring light winds and mostly clear skies
tonight, and the dry air mass should allow optimal radiational
cooling. Have nudged low temperatures a bit below the NBM, with
upper to locally mid 30s possible in favored cooler drainage
locations. Cannot rule out some very patchy frost and added a
mention of frost to the forecast for the coolest locations along
the Buffalo Ridge and into portions of northwest Iowa tonight.
Neither confidence nor coverage are high enough to hoist an
advisory at this time though.

The coldest air is short-lived across our area with weak warm
advection resuming through the day Tuesday while a last gasp
backdoor cool front drops into northern Minnesota behind the
departing upper trough. The remainder of the week ahead will be
dominated by a broad mid-upper level ridge building back into
the nation`s midsection. A modest wave tops the ridge midweek.
Will see breezier conditions develop in response to this wave
Wednesday (mainly west of I-29) and Thursday, which may bring
areas of elevated fire weather concerns. Rainfall chances with
the wave are uncertain as models vary on the availability of
sufficient moisture. If we see any showers, Thursday seems to
be the favored day. Ensembles are only showing <20% chance of
rainfall exceeding 0.10", so any rain would be rather light.

The prevailing ridge persists into the weekend, shifting a bit
farther east by Sunday. Warmer air continues to build beneath
the ridge, bringing a moderate (50-70%) probability of highs
climbing back into the 80s for parts of the area again by
Saturday (southwest) and Sunday (southeast). Breezy southerly
winds accompany the warmer temperatures, so will have to watch
for areas of elevated fire danger again by next weekend. Some
faster model solutions push the upper ridge well east into the
Great Lakes by late Sunday as a deep trough from the Canadian
Prairies into the Rockies swings into Plains. If these faster
solutions pan out, we could see rain chances accompany a sharp
cold front into the area late in the weekend. However, too much
divergence in model solution timing/strength to adjust the NBM
low (20-30%) pops at this range.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1150 AM CDT Mon Oct 6 2025

VFR conditions continue across the region at mid-day Monday.
Very light sprinkles to showers will continue to focus across
portions of Iowa and Nebraska through mid-afternoon. Otherwise a
continuation of a mid-lvl and upper cloud deck will persist
overnight as winds turns variable.

A weak secondary front drifts towards Highway 14 early Tuesday
morning, bringing more high based sprinkles southward towards
I-90 by mid-day. VFR conditions are expected.


&&

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

&&

$$

DISCUSSION...JH
AVIATION...Dux