777
FXUS63 KFSD 052106
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
306 PM CST Fri Dec 5 2025

.KEY MESSAGES...

- A quick-moving winter system will bring mainly 3-6" of snow
  for areas along and east of the James River Saturday into
  Saturday night. Locally higher amounts over 6 inches looks
  possible mainly in and around the Iowa Great Lakes into the
  Jackson, Minnesota area.

- Snowfall rates could be as high as 1-1.5" an hour in the
  heaviest snow especially Saturday afternoon and early evening,
  which would cause visibility reductions and quickly
  accumulating snowfall. Be sure to use extra caution on the
  roads and prepare for potential travel delays.

- Cold wind chills move in once again Saturday night, with wind
  chills down to the -5 to -15 degree range by Sunday morning.

- Near to below normal temperatures will continue into the new
  week with the next chances for precipitation possible on
  Tuesday.

&&

.DISCUSSION...
Issued at 302 PM CST Fri Dec 5 2025

It was a much warmer day out there today compared to yesterday,
with highs into the 30s area-wide. Spotty snow and rain showers
continue to push across the area, but we should dry out heading
into tonight. Temperatures will drop tonight behind a weak
frontal boundary into the lower 10s to lower 20s, so a chilly
night is ahead. This will set the stage for our next snowmaker
set to impact the area during the day Saturday into Saturday
evening. A band of snow looks to develop off to our west around
daybreak Saturday and push eastward into our area. Snow should
begin around sunrise west of the James River, by the late
morning/early afternoon time frame for the I-29 corridor, and
then spread into the rest of northwest Iowa and southwest
Minnesota through the afternoon. Due to the later start time
expected for the I-29 corridor, did move the start time up for
the Winter Weather Advisory there to begin at 9 am Saturday.
Snow should wrap up from west to east through the evening hours.
This is slightly slower than what guidance was showing
overnight, so opted to extend the Winter Weather Advisory for
northwest Iowa and southwest Minnesota until midnight Saturday
night/Sunday morning.

Unlike our last winter storm, which was more of a slowly
developing system, this one will be quick moving with higher
snowfall rates, potentially up to an inch to inch and a half per
hour at times especially in the afternoon and early evening
hours. This means snow will accumulate quickly after it begins
and visibility will be reduced. Speaking of accumulations, we
look to generally see around 3-6" along and east of the James
River. West of there, amounts looks to be in the 1-3" range. The
highest snowfall totals will be in and around the Iowa Great
Lakes to the Jackson, MN area, where locally 6-7 inches of snow
will be possible. Opted to not upgrade to a Winter Storm Warning
for these areas for two reasons. One, amounts of at least 6
inches or more are expected to remain isolated at this time, and
without excessive wind to blow things around, we won`t be
anywhere near whiteout concerns or anything like that. Second,
guidance has been a bit inconsistent on where the heaviest
snowfall rates will end up, with some guidance indicating this
heavier band setting up either along the I-90 corridor in
southwest Minnesota, or over portions of northwest Iowa, or
even into central Iowa (out of our county warning area). Future
upgrades may be necessary if guidance either starts to signal
more widespread 6+ inch totals or if guidance comes into better
agreement, so keep up to date with the latest forecast! Either
way, extra caution should be used on the roadways on Saturday.

From there, we get colder, with temperatures Saturday night dropping
to the single digits on either side of zero. Wind chills look to be
in the negative 5 to negative 15 degree range by Sunday morning.
Highs on Sunday only look to be mostly in the single digits to low-
10s, perhaps slightly warmer where less snowpack is expected (south-
central SD). Temperatures look to moderate heading into the next
work week, with temperatures rising above freezing across the entire
area by Tuesday. Another storm system will move in Tuesday into
Tuesday night. With the warmer temperatures in place, there`s a
chance this system starts out as all rain, with perhaps a changeover
to snow on the backside of the system. Details remain uncertain as
it will come down to the track of the system, which this many days
out is highly uncertain. Either way, temperatures look to cool off
below normal again after this system moves through.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1139 AM CST Fri Dec 5 2025

Scattered rain and snow showers (with some freezing rain and sleet
mixed in) continues to move from northwest to southeast across the
area. Guidance is doing a poor job handling the precipitation, but
it does look to remain hit or miss in nature heading into the
afternoon. So there will be chances for precipitation (mainly a
rain/snow mix) at the terminals through the afternoon and early
evening. We`ll get a period of dry weather overnight before our next
round of precipitation arrives, which is expected to be
all snow at this time. A band of snow looks to develop over
central South Dakota around daybreak tomorrow morning and move
eastward through the morning, reaching the terminals during the
last few hours of the period. MVFR visibilities are expected
with the snow initially, but heavier snow rates will likely
arrive just after this TAF period.

CIGS will be a mix of IFR and MVFR through the period, with some
scattering out of the lower cloud deck at KSUX around midnight
tonight before filling back in tomorrow morning. Expect IFR CIGS
when tomorrow`s round of snow arrives at the terminals. Winds this
afternoon will be out of the northwest around 8-12 kts, higher in
south-central South Dakota up to 12-18 kts. Winds turn light and
variable tonight and look to pick up again through tomorrow morning
out of the east-southeast.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory from 9 AM to 9 PM CST Saturday for
     SDZ040-055-056-061-062-066-067-069>071.
     Winter Weather Advisory from 6 AM to 6 PM CST Saturday for
     SDZ038-039-052>054-058>060-064-065-068.
MN...Winter Weather Advisory from noon Saturday to midnight CST
     Saturday night for MNZ071-072-080-081-089-090-097-098.
IA...Winter Weather Advisory from noon Saturday to midnight CST
     Saturday night for IAZ001>003-012>014-020>022-031-032.
NE...Winter Weather Advisory from 9 AM to 9 PM CST Saturday for
     NEZ013-014.

&&

$$

DISCUSSION...Samet
AVIATION...Samet