AFOS product AFDFSD
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Displaying AFOS PIL: AFDFSD
Product Timestamp: 2025-12-11 09:40 UTC

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FXUS63 KFSD 110940
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
340 AM CST Thu Dec 11 2025

.KEY MESSAGES...

- Flurries to light snow this morning will transition to a 
  wintry mix of freezing rain, snow, and sleet mainly west of a 
  De Smet-Sioux Falls-Cherokee, IA line. Ice accumulations will 
  range from a glaze to a 0.15" of an inch with the highest 
  accumulations west of the James River Valley. 

- Mainly light snow will occur east of the previously mentioned
  line with 1-3 inches of fresh snow expected. The highest
  accumulations will likely occur across southwestern MN.

- The combination of slippery road conditions and accumulating 
  snowfall will lead to minor travel impacts especially during 
  the morning commute.

- Confidence continues to increase in accumulation snowfall on
  Saturday especially along the Missouri River Valley. Overall
  amounts continue to trend towards the 1-3 inch range. 

- An influx of arctic air over the weekend will lead to cold
  temperatures and even colder winds chills especially by Sunday
  morning. Wind chill values as low as -30 degrees will be
  possible.

&&

.DISCUSSION...
Issued at 330 AM CST Thu Dec 11 2025

TODAY & TONIGHT: A wintry day ahead! Taking a look across the area, 
we're continuing to see areas of flurries to light snow streaming 
into areas west of the James River Valley this morning. The forecast 
remains on track for areas of light snow to transition to a wintry 
mix of freezing rain, sleet, and snow as 800:900 mb temperatures 
warm with the approaching surface warm front. While the defining 
line between snow and wintry mix likely sits west of a De Smet to 
Sioux Falls to Cherokee, IA line; we'll continue to see precipitation
coverage expand to the southeast over the course of the morning
with the mid-level wave. With accumulative ice amounts expected
to range from between a glaze to 0.15" of an inch with the highest
amounts west of the James River Valley, slippery road conditions
are expected in the areas of highest accumulation. With this in
mind, minor travel impacts are expected during the morning 
commute so make sure to slow down and drive to the conditions!

Shifting gears here, mainly light snow will continue east of the 
previously mentioned line with the potential for sleet mixing in 
nearest the line itself. Looking aloft, snowfall rates could see a 
slight uptick by late morning mainly across southwestern MN as 
increasing dPVA and mid-level frontogenesis lead to a narrow 
corridor of enhanced snowfall. Within this area, snowfall rates 
between 0.25" to 0.50" in/hr will be possible at times according to 
the HREF. With this in mind, where the highest rates develop will 
likely carry our highest accumulations for this event. Nonetheless, 
snowfall accumulations 1-3 inches are expected with the highest 
accumulations in southwestern MN. With all this in mind, a Winter
Weather Advisory remains in effect from 6 am through 6 pm for 
most areas besides along the Missouri River Valley. Lastly, with
the progressive nature of this system; conditions should begin 
to clear from northwest to southeast over the course of the evening.

THE WEEKEND: Heading into the weekend, mostly quiet conditions are 
expected for most of the day on Friday. However, this will be short-
lived as another mid-level clipper swings through the area from 
Friday night into Saturday bringing renewed chances for snow. 
Looking at deterministic guidance, most guidance continues to point to 
1-3 inch amounts so far with the focus being across the Missouri 
River Valley. With that being said, uncertainty with the track could 
still shift the highest amounts northwards or southwards over the 
next couple of days so continue to monitor you local forecast as the 
details could change! Otherwise, the other concern continues to be 
on the colder temperatures and even colder wind chills. As an influx 
of arctic air and a fresh snowpack helps temperatures plummet into 
the single digits to teens over the weekend, we'll likely see sub-
zero wind chills return to the area each night through Sunday. 
Sunday morning continues to look like the peak of the coldest 
conditions with values between 20 to 30 below zero expected. We'll 
likely need a cold weather headline these or colder values occur.

NEXT WEEK: Looking into the new week, quieter conditions likely 
return from Monday onwards as an upper-level ridge resets our 
overall pattern to quasi-zonal flow. While there will be a few waves 
that push through between Monday and Wednesday, highs will likely 
hover near to just above freezing. With this in mind, this will be 
a welcomed change from the wave train moving forward. 

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1020 PM CST Wed Dec 10 2025

VFR conditions have moved into most areas of the Tri-State area
late this evening. However, these conditions won't last long as
initial wave of warm advection light snow is trying to develop
over central South Dakota.   

Through daybreak flurries may redevelop and move eastward, as
ceilings gradually lower. More intense forcing and rapidly
worsening conditions develop after daybreak in central South 
Dakota, spreading east towards I-90 by mid-morning and eastward 
through the mid-day hours. MVFR to IFR conditions are likely, 
and in moderate snow, visibility may drop below 1/2 mile at 
times. A narrow corridor of sleet may also develop along a Huron
to Sioux Falls line at times, and have indicated the greatest 
potential for this weather type around mid-day. 

Low ceilings and weak lift persist into the evening, with some
potential for freezing drizzle to develop into the evening.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory until 6 PM CST this evening for SDZ039-
     040-054>056-060>062-065>067.
     Winter Weather Advisory until 3 PM CST this afternoon for 
     SDZ038-052-053-057>059.
MN...Winter Weather Advisory until 6 PM CST this evening for MNZ071-
     072-080-081-089-090-097-098.
IA...Winter Weather Advisory until 6 PM CST this evening for 
     IAZ001>003-012>014-021-022.
NE...None.

&&

$$

DISCUSSION...05
AVIATION...Dux