210
FXUS63 KFSD 301155
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
655 AM CDT Fri Oct 30 2026

.KEY MESSAGES...

- Patchy fog, some locally dense, will continue mainly over
  southwest Minnesota through the mid morning hours. Use extra
  caution if driving in these area and be prepared for rapidly
  changing visibilities.

- Spotty light showers are expected this morning mainly over
  northwest Iowa. Showers and very isolated thunderstorms are
  likely tonight into Saturday morning, mainly near and east of
  Highway 81. Drizzle and spotty showers will be possible west
  of Highway 81.

- More widespread rain returns later Sunday night into Monday.
  Latest guidance suggests about a 40-70 percent chance for
  more than an inch of rain.

&&

.UPDATE...
Issued at 326 AM CDT Fri Oct 30 2026

A surface high continues to slide towards the western
Great Lakes allowing for winds to be slightly higher tonight
than compared to last night. This should help limit widespread
fog development, but since it will take a bit longer for winds
to increase over southwest Minnesota, patches of fog have
already developed there early this morning. We will continue to
see fog in these areas (especially closer to the Highway 14
corridor of SW MN) through the morning commute. Fog has already
been locally dense at times especially in and around the
Marshall area, but widespread dense fog is not expected. Still,
be prepared for quickly changing visibilities on the roads this
morning and consider leaving extra time to get to your
destination. Any fog should lift by 10 am.

Looking at radar across the region, showers and thunderstorms
have developed mainly along and just north of the I-80 corridor
in eastern Nebraska and western Iowa, with this activity lifting
east-northeastward. Seeing a few weak returns developing north
of this along the Highway 20 corridor, and we`ll continue to see
spotty showers here through this morning. Thunderstorms do look
unlikely here given limited instability, so light showers are
expected. As warm air advection slowly increases northward
heading into later portions of the day today, so will the chance
of showers. Perhaps a little more elevated instability late
this afternoon into the overnight, thus can`t rule out some
weak thunderstorms. If a storm develops, the main difference it
would bring would be locally higher rainfall amounts, but
otherwise most of the showers today and tonight should remain on
the lighter side. Outside of any showers, patchy drizzle with
be possible as well.

We`ll continue to see showers and isolated thunderstorms
through the overnight hours tonight, with activity gradually
lifting northeastward and moving out of the area heading through
the morning hours on Saturday. A secondary wave moving across
western South Dakota, albeit a bit of weaker one, may help keep
some showers in the area through the day on Saturday. Even
without the showers, low stratus will remain in place with
soundings showing some shallow instability within this layer.
This will allow for more patches of drizzle through the day
Saturday, especially in the morning when the stratus deck will
be closest to the surface.

Another system enters the picture Sunday night into Monday,
with near universal agreement amongst guidance that we will get
a decent rain with this. As such, NBM PoPs are already pushing
100%, which is also in line with the global 30.00Z ensembles.
However, there is still some uncertainty regarding the track of
the low and and where and when the heaviest rain sets up, so
keep up to date with the latest forecast and be prepared for a
rainy day on Monday!

&&

.DISCUSSION...
Issued at 104 PM CDT Thu Oct 29 2026

Weak ridging aloft moves through the area tonight into Friday. This
will allow for an increase in south to southeast flow in the lower
levels. Models soundings point towards some possible patchy fog
again later tonight, but stratus should increase from south to north
late tonight into Friday afternoon. So for now not anticipating
widespread fog issues. Other than the increasing stratus through the
day, Friday should mostly be dry. By afternoon into the evening a
wave will rotate northward bringing slightly cooler temperatures
aloft above the increasing low level moisture. This should bring
some weak instability with maybe 200-500 J/kg CAPE and no real shear
to speak of. This the expectation will be for mainly scattered
showers with isolated thunderstorms. The better chances for showers
and isolated thunderstorms should be near and east of I-29 with
areas near and west of the James River possibly capped and seeing a
better chance for drizzle with roughly the lowest 5000 feet
saturated and weak lift moving through. For now rainfall amounts
look light with some spotty tenth of an inch or so possible.

Saturday the challenge will be trying to break through a fairly deep
stratus layer as weak upper level support gradually diminishes. For
now expect cloud cover the linger and temperatures to not reach
their full potential, likely topping out in the lower 60s in most
locations. Still mild for this time of year.

Saturday night into Sunday expecting mainly dry conditions as
saturation aloft diminishes and any weak instability is gone. Sunday
will likely see a resurgence of stratus ahead of the next wave coming
Sunday night into Monday. This should again keep high temperatures
mostly in the lower 60s.

Sunday night will see a surge of warm air advection in the lower
levels as low pressure deepens to the west southwest and an initial
wave races by to the northeast. Would not be at all surprised if we
see enough instability Sunday night into Monday morning to produce
a few thunderstorms as the band of strong warm advection moves
through. After this a few question marks on low pressure
development. With the jet still pretty strong and southwest of the
main trough, expect low pressure to deepen across KS/NE area, then
lift east or northeast into Tuesday. The low pressure movement is
fairly low confidence as the models are yet to agree upon how much
jet energy wraps around to the east side of the low, but if enough
does, we could see rainfall continue well into Tuesday. For now even
on the backside of this system it is a bit too warm for snow, so
thinking all rain.

If this system were to wrap up as much as the ECMWF suggests, a few
snow showers would be possible Wednesday into Thursday, but not a
lot of support from other models, so nothing more than something to
keep an eye on.

As for precipitation amounts, the latest GEFS is still bullish
bringing over an inch of rainfall to many locations, with a 50-60
percent chance in far southeast SD, northwest IA and northeast NE.
The latest AI model information leaning towards the lower side on
rainfall amounts which worked well with the rain event this past
Monday when many models (lower and hi res) and ensembles were
indicating a widespread 1-2.5" of rain and we saw something closer
to 0.50 to 1.25 inch rainfall amounts.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 651 AM CDT Fri Oct 30 2026

Areas of fog, some locally dense, have developed over portions
of southwest Minnesota mainly from KMML to KMWM this morning. This
will continue to impact the area until the fog lifts by around
15z. MVFR stratus currently over eastern Nebraska will lift
north across the area as the day progresses, continuing into
tonight. Cigs will also gradually lower, with IFR conditions
expected to return gradually from south to north tonight.

Scattered showers with very isolated thunderstorms will increase
in coverage this evening into the overnight hours, but
confidence was not high enough in coverage of thunder to include
mention in the TAFs at this time. Winds will be out of the
east-southeast today, turning more southeasterly heading into
tonight. Winds will be fairly light through the period,
sustained around 5-10 kts.

&&

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

&&

$$

UPDATE...Samet
DISCUSSION...08
AVIATION...Samet