495
FXUS63 KFSD 132325
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
525 PM CST Sat Dec 13 2025

.KEY MESSAGES...

- A brief influx of arctic air will lead to cold temperatures
  and even colder wind chills (as low as -25 to -30F) tonight
  into Sunday morning.

- Quieter conditions with mild temperatures return next week,
  though fresh snowpack may impact how quickly temperatures warm
  early in the week.

- Wednesday night into Thursday will be the next system with the
  potential for impacts across the area. More of a wind threat
  than precipitation threat but if any snow can fall with the
  cold surge, blowing snow will be possible.

&&

.DISCUSSION...
Issued at 159 PM CST Sat Dec 13 2025

Arctic high pressure builds south tonight which will allow for
lighter winds over fresh snowpack. This should lead to lows mainly
from -10 to -20. When coupled with the light winds, wind chill
values will average about -15 to -30, resulting in a cold weather
advisory for parts of the area.

High pressure quickly shifts east on Sunday which will bring a bit
warmer temperatures, but much breezier conditions. With the fresh
snow cover it is likely we will not mix down as strong of winds as
possible, but suspect gusts will be in the 20 to 30 mph range. With
these stronger winds and the fluffy snowpack, expect some patchy
blowing and drifting during the day into the evening on Sunday.

Milder air builds into the area Monday and while much of the warmth
will not be realized at the surface due to the recent fresh snow
cover, temperatures will still climb back to around normal. Areas
west of the James River with less snow cover will see temperatures
climb into the low to mid 40s.

A fairly strong upper level jet moves through the area on Tuesday
but will be fighting plenty of dry air so at this time
precipitation looks very unlikely. Mid level clouds and saturation
in the DGZ look likely, but the DGZ is also very elevated and will
not be able to fight through the lower level dry air. Ahead of this
wave on Tuesday much warmer air will surge into the area and highs
from the mid 30s in northwest IA to around 50 over snow free areas
is expected.

Shortwave ridging on Wednesday ahead of a very strong wave expected
Thursday will bring another mild day to the area. Assuming snow
cover has diminished with the milder temperatures Monday and
Tuesday, widespread 40s are expected with highs in the 50s west of
the James River.

Strong low pressure moves into the area on Thursday and is expected
to deepen near the ND/Canadian border, then drift east with a strong
wave expected to dive southeast behind this deepening low pressure.
The west/northwest winds ahead of this Thursday will potentially see
gusts around 50 mph, then the strong wave on the backside will turn
winds more northerly with a potentially very strong and compact push
of cold air and a continued threat for 50+ mph winds.  Plenty of
warming ahead of this cold surge that any blowing snow will be
relegated to anything that can get squeezed out of the cold surge as
low and mid level temperatures crash into the DGZ. Not out of the
question for a short duration, 3-9 hour, low visibility situation
with snow and blowing snow. But again, any existing snowpack will
likely not be blowable after multiple mild days.

Some disagreement comes in for Friday and Saturday, so confidence a
little lower. Models leaning slightly towards a warm surge Friday,
then colder air filtering in behind for the weekend.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 524 PM CST Sat Dec 13 2025

Conditions remain vastly VFR early this evening as there remains a
little MVFR stratus just barely touching K9V9. Clear skies and light
and variable winds will persist for the evening and overnight hours.
Winds will pick up out of the south tomorrow and strengthen with
gusts up to 20-30 knots. The breezy winds may lead to patchy blowing
snow as well to finish out the TAF period.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Cold Weather Advisory until 10 AM CST Sunday for SDZ038>040-
     053>056-059>062-065>067.
MN...Cold Weather Advisory until 10 AM CST Sunday for MNZ071-072-
     080-081-089-090-097-098.
IA...Cold Weather Advisory until 10 AM CST Sunday for IAZ001>003-
     012>014-021-022-032.
NE...None.

&&

$$

DISCUSSION...08
AVIATION...Meyers