AFOS product AFDFSD
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Product Timestamp: 2025-12-10 20:09 UTC

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FXUS63 KFSD 102009
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
209 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.

&&

.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 /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1134 AM CST Wed Dec 10 2025

MVFR ceilings will gradually drift east through the day, but it
will be slow going. Model soundings do indicate the moisture in
this layer becoming more shallow so we may see some breaks by
mid to late afternoon moreso than advecting the entire mass of
stratus east. Otherwise mid level clouds will spread across the
area overnight with a mix of freezing rain and snow expected on
Thursday morning. The better chances for this mix will be near
and north of I-90. Southwest MN will see a better chance for
mainly snow by late morning while east central SD will see a
mix, with maybe more freezing rain thatn snow near and west of
highway 81.

&&

.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.

&&

$$

DISCUSSION...08
AVIATION...08