430
FXUS63 KFSD 041739
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
1139 AM CST Thu Dec 4 2025

.KEY MESSAGES...

- A very cold morning with wind chills as cold as -25 east of
  the James  River and to -15 west of the James River.

- Wind gusts nearing 40 mph this afternoon over southwest
  Minnesota and nearby parts of eastern South Dakota and
  northwest Iowa will lead to patchy blowing snow. Please use
  extra caution on the roads.

- Light precipitation is expected late tonight into Friday
  evening with minor accumulations. A mix of precipitation could
  lead to minor accumulations.

- Confidence is increasing in the potential for accumulating
  snowfall Saturday into Saturday night, as models come into
  more agreement. Chances for at least an inch of snow are high
  (over 70%). Guidance still varies on where the heaviest
  snowfall may fall. If you have travel plans, keep an eye on
  the forecast.

- Cold, below normal temperatures are expected to continue
  through the weekend, with signs of temperatures moderating
  closer to normal next week.

&&

.DISCUSSION...
Issued at 301 AM CST Thu Dec 4 2025

TODAY: Surface high slides east through this morning. Guidance
continues to handle stratus poorly west of the James River, which
has been moderating temperatures somewhat in this area. 2 AM
temperatures are below zero for most, with wind chills in the teens
to mid 20s below. Still may see some locations east of I-29 briefly
drop below Cold Weather Advisory criteria, but have remained
headline free given marginal and brief conditions. We should warm
into the teens (east) to mid 30s (south central SD).

WAA increases today, and we`ll see a tightening surface pressure
gradient as well as increased mixing. This allows for a breezier
day, with southerly winds gusting around 35 to 40 mph - strongest in
our higher elevations of the Buffalo Ridge. Main concern with these
stronger wind gusts will be the potential for blowing snow. Blowing
snow could lead to locally reduced visibility and patchy slick spots
so be prepared for changing conditions this afternoon and evening.

TONIGHT-FRIDAY: Raised pops and QPF from the NBM with guidance
coming into better agreement with light precipitation thanks to a
stronger mid level wave and a surface boundary moving through the
area after midnight and into Friday. However, there are still some
questions regarding how much we`ll saturate the column and in the
DGZ, so could see some light freezing rain or freezing drizzle.
Light precipitation looks to be largely be focused along and north
of I-90 into northwestern IA. Any accumulations through the day
Friday and into Friday night remain light, less than half an inch.
Lows tonight fall into the teens and 20s with highs Friday in the
30s.

SATURDAY-SATURDAY NIGHT: Models are coming into more agreement with
a stronger wave/trough swinging through the central Plains Saturday
into Saturday night. The 04.00 GFS/NAM remain the furthest south
with the precipitation, while the Canadian is further north and the
ECMWF is in the middle. Differences seem to largely be from where
the surface warm front and moisture advection end up. The increased
agreement is now reflected in the ensemble data as well, with a
significant increase in the chances for a tenth of an inch of
precipitation from 15-35% with the 03.00z runs to 55-85% with the
04.00z ensemble data. Similar increases can also be seen in the
potential for more than 0.25" during the same period. Again, there
are still varied in the location of the heaviest precipitation, but
certainly watch the forecast if you have travel plans. Chances for
an inch of snowfall are high (over 65%), and for 2" inches are
moderate to high (40-70%). Chances for greater than 4" of snow are
low (less than 30%). However, this may still change.

Much colder air returns Saturday night with lows below zero.

SUNDAY: Much colder air continues region Sunday with high pressure
returning. Highs may not exceed the single digits east of I-29, with
the teens elsewhere. Some guidance shows brief but light snow
Sunday, but confidence is low in this potential. Another cold night
Sunday night, in the single digits either side of zero.

MONDAY-MID WEEK: Northwesterly flow regime keeps a more active
pattern in place early to mid next week. Strongest wave is currently
progged to move through Tuesday night into Wednesday, which could
bring light precipitation back to the region. Details are uncertain.
Regardless, below to near average temperatures continue through mid
week.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1138 AM CST Thu Dec 4 2025

An area of stratus will continue to slowly erode and move eastward
across the area through the afternoon, with the return of VFR
conditions expected at KFSD and KSUX by the late afternoon to early
evening. Tonight, some guidance shows the potential for fog
development, but left it out of the TAFs for now. Trends will be
monitored, but right now it looks like winds should stay elevated
enough to prevent widespread fog development. Our next system moves
in late tonight into tomorrow morning, brining the potential for
snow mixed in with some light freezing rain at times. Kept it as
snow in the TAFs for now as that is the most likely precipitation
type, but can`t rule out some light freezing rain (<25% chance at
the terminals). The best chance of snow will be north of I-90
especially into southwest Minnesota late tonight into tomorrow
morning. Heavy snow is not expected at this time, but any
snowfall could lead to MVFR visibilities.

Winds will gust to around 25-30 kts this afternoon (up to around 35
kts along the Buffalo Ridge) out of the south-southwest. Winds will
diminish overnight, though still could see a few gusts up to around
20 kts in southwest Minnesota and adjacent northwest Iowa late
tonight. Winds will turn more west-northwesterly heading into
tomorrow morning, picking up to around 8-12 kts by the end of the
period.

&&

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

&&

$$

DISCUSSION...SG
AVIATION...Samet