181
FXUS63 KFSD 021947
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
147 PM CST Fri Jan 2 2026

.KEY MESSAGES...

- Wintry mix risks remain focused along or south of the
  Missouri River this afternoon, with flurries elsewhere.

- A light wintry mix of freezing drizzle or snow may develop
  along and east of of I-29 into the overnight hours.
  Accumulations expected to remain light, but isolated slick
  spots possible.

- A small risk for fog tonight (west of the James River), and
  Sunday morning (east of the James River). Patchy dense fog
  possible.

- Other than a couple of nuisance precipitation chances Sunday
  night and Tuesday, a quiet and seasonally warm forecast is
  ahead for next week.

&&

.DISCUSSION...
Issued at 133 PM CST Fri Jan 2 2026

THIS AFTERNOON: Compact area of vorticity sliding east and
slightly southeast through Nebraska has struggled to pivot
northward or strongly influence conditions north of the
Missouri River. This is partially due to a lingering mid-lvl dry
layer in place. However, we have received a report or two of
very light icing along the Missouri Valley, so will continue
advisory already in place. In SW Minnesota, a small bit of
clearing along and east of the Ridge is leading to convective
snow showers downstream towards the SD/MN border.

TONIGHT: The aforementioned area of vorticity will continue to
drift southeast early this evening, with weak isentropic lift
leading to a light wintry mix to snow along the MO river into NW
Iowa early this evening. Any ice or snow accumulation will be
light. As low-lvl moisture layer thickens this evening, we`re
seeing broad signs for weak to modest warm advection through the
layer developing and persisting into the overnight hours mostly
along and east of I-29. Soundings suggest a period of light
freezing drizzle into the overnight hours, with saturation and
lift below 750 mb. Between 750 and 600 mb is a stubborn dry
layer, with further saturation above 600mb suggesting that
seeder/feeder mechanisms could also lead to a bit of light snow
mixing in. Overall, given spread dew point depressions at the
surface, any accumulation should remain very light. Further
west, CAMs suggest a 30 to 40 percent probability for fog to
redevelop west of the James River.

SATURDAY: Quite a bit of cloud cover will start the day on Saturday.
with light winds leading to a slower erosion of low-lvl stratus
through the day. That said, we should see some clearing from
west to east in the afternoon with highs climbing into the upper
30s near the Missouri River to the mid-20s over the Buffalo
Ridge. Some guidance suggests that as warm advection streams
east Sunday night and inversion steepens we could see a bit of
fog development by Sunday morning.

SUNDAY: Mid-lvl vorticity traveling through the Dakotas will
increase mid-lvl clouds through the day.  With the return of breezy
southwesterly winds and 850 mb temperatures near 14C, temperatures
will surge into the 40s in most locations.  Lingering stratus and
timing of the shift towards a SW surface wind will really determine
just how much warm air moves east.

MONDAY-THURSDAY: Any light precipitation that may develop with a
passing wave Sunday night will be quickly pushed east at the start
of the new work week. The vast majority of the week will feature
zonal mid-lvl flow through the CONUS, suggesting a prolonged
stretch of above normal temperatures. Highs most days will
climb into the 40s, with very warm days focused near Wednesday
and Thursday. While most of the week will remain dry, a weak
system moving through the Dakotas Tuesday could bring a very
light wintry mix to the northern portions of the CWA. There are
some rumblings of a system coming through the region next
Thursday/Friday though ensemble spread is extremely high, so
buying into any one deterministic model as the solution should
be avoided.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1107 AM CST Fri Jan 2 2026

MVFR to IFR ceilings continue move through the Tri-State area as
a compact shortwave crosses Nebraska. Infiltrating dry air in
the mid-lvls continues to limit precipitation development, but
some better focus will develop along the Missouri River by mid-
afternoon.

Warm advection spreads across the area after dark, but
especially focuses along and east of I-29. Soundings suggest a
mixture of very light snow (seeder-feeder), and freezing
drizzle (warm advection) for a handful of hours as ceilings drop
once again. Precipitation chances will slide east by 3am.

Winds remain light into Saturday morning, leaving an overcast
IFR or lower ceiling in place.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory until 6 PM CST this evening for SDZ050-
     063-068.
MN...None.
IA...None.
NE...None.

&&

$$

DISCUSSION...Dux
AVIATION...Dux