694 
FXUS63 KFSD 110234
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
834 PM CST Wed Dec 10 2025

.KEY MESSAGES...

-  Winter weather advisory for mixed precipitation expanded for
   areas mainly near and north of I-90 and near and west of 
   I-29. A band of snow will likely transition to a period of 
   freezing rain through the morning into the early afternoon 
   Thursday. Still some disagreement on location and amounts so 
   further expansion and contraction of the advisory is 
   possible.

-  A band of snow will be possible on Saturday. For now the 
   better chances appear to be near and south of I-90. Overall 
   looking like 1- 3 inch amounts.

-  Confidence continues to increase in arctic air bringing near
   advisory level wind chills to the region by this weekend.

-  Depending upon how much snow falls through Saturday, a 
   milder pattern sets up for early next week.

&&

.UPDATE...
Issued at 826 PM CST Wed Dec 10 2025

Quick look of the 00Z model guidance supports a slightly slower
arrival of warm air on Thursday. The HRRR seems to be lifting
the wave and warm advection too far northeast. This may place 
the transition zone a bit more along a line from Huron to Sioux 
City. Additionally, the intensity of the WAA is not quite as 
strong, suggesting a narrow corridor of a bit more sleet and 
potentially forcing more of the freezing rain risks along and 
west of the James River Valley. 

The resultant modifications in the p-type probability forecast
suggests a bit more snow/sleet in areas from Madison to Sioux
Falls to Cherokee with accumulation of 0.5 to 1.5". Snow amounts
may trend upwards in areas of SW MN and NW IA as well, with
potential for 3" in some areas. 


&&

.DISCUSSION...
Issued at 208 PM CST Wed Dec 10 2025

A fairly strong wave will drop southeast through strong northwest 
flow aloft late tonight into Thursday. Given thermal profiles across 
the area concerns continue for a combination of freezing rain and 
snow, especially near and west of I-29 and near and north of I-90. 
Across southwest MN the majority of the precipitation would be snow 
and for now those amounts would likely be 1-3". Also of concern with 
this will be the precipitation increasing through the morning and 
possibly beginning near the morning rush, although locations closer 
to I-29 should see a start time closer to 8-10 am. Currently it 
looks like precipitation will start as mainly snow, then transition 
to freezing rain after a period. The impacts from any freezing rain 
will be dependent upon how much snow falls first. For now snow 
amounts before the freezing rain look to be fairly minimal so 
believe that there will be some minor to moderate impacts from the 
freezing rain, especially with the now bare roads and no snow or 
slush to absorb some of this liquid precipitation as it is freezing. 
So went ahead and expanded the advisory south to I-90 and east just 
into MN and far northwest IA. Areas east of this advisory will see 
more snow than freezing rain and amounts for now do not warrant an 
advisory. Will also need to monitor potential for a light icing 
south of I-90 Thursday morning into the afternoon but for now 
confidence not high enough in this area for an advisory.

By late afternoon this lift will shift southeast and colder air will 
filter southward. This should shut down precipitation from northwest 
to southeast. Model soundings do indicate some saturation in the 
lowest few thousand feet so will need to monitor for the potential of 
a little light freezing drizzle as this system exits.

Otherwise a jet digs into northern MN and drags further cold air 
into the region on Friday. This will bring a cold Friday to the 
region with highs in the teens and wind chills dropping below zero 
in many locations Friday afternoon.

The next chance for snow will come Friday night into Saturday. While 
the wave is much weaker, thermally we are primed for snow 
production. The DGZ basically runs from near the surface to about 
600 mb. With somewhat weaker winds in the lower 2000 feet or so this 
could prove to be a fairly efficient snow maker. 

Cold air funnel in behind this system and Saturday night into Sunday 
looks very cold. Could potentially see cold weather advisories 
across the area during this time.

Sunday night into the middle of next week will see a pattern chance 
with ridging building, then flat westerly flow expected, supporting 
milder flow aloft and at the surface. Will have to keep an eye out 
for a system Wednesday into Thursday.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 507 PM CST Wed Dec 10 2025

MVFR ceilings slowly crawl eastward this evening, taking a few
lingering flurries with it. 

Clouds won't clear however, as ceilings begin to lower from west
to east ahead of the next wave moving into the Plains. Very high
based snow may develop over central South Dakota by midnight,
with stronger surge of moisture and lift producing a winter mix
moving eastward during the day on Thursday. A layered mess of
snow, then freezing rain and sleet will develop through the
Tri-State area, with the mix of wintry types on the southwestern
side of the precipitation band. Ceilings and visibility may
occasionally fall to IFR or lower levels into mid-afternoon.

Current TAFS do not indicate sleet due to type simplicity, but
aviation interests should be aware of it's increased risk from
mid-morning to mid-afternoon. Ice accumulations up to one tenth
will be possible, with mixed snow and sleet accumulations of a
dusting to an inch or two.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory from 8 AM to 6 PM CST Thursday for 
     SDZ039-040-054>056-060>062-065>067.
     Winter Weather Advisory from 3 AM to 3 PM CST Thursday for 
     SDZ038-052-053-057>059.
MN...Winter Weather Advisory from 8 AM to 6 PM CST Thursday for 
     MNZ071-097-098.
IA...Winter Weather Advisory from 8 AM to 6 PM CST Thursday for 
     IAZ001.
NE...None.

&&

$$

UPDATE...Dux
DISCUSSION...08
AVIATION...Dux