AFOS product AFDFSD
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Displaying AFOS PIL: AFDFSD
Product Timestamp: 2025-12-04 09:03 UTC

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FXUS63 KFSD 040903
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
303 AM CST Thu Dec 4 2025

.KEY MESSAGES...

- A very cold morning with wind chills as cold as -25 east of
  the James  River and to -15 west of the James River.

-  Wind gusts nearing 40 mph this afternoon over southwest
   Minnesota and nearby parts of eastern South Dakota and
   northwest Iowa will lead to patchy blowing snow. Please use 
   extra caution on the roads.

- Light precipitation is expected late tonight into Friday
  evening with minor accumulations. A mix of precipitation could
  lead to minor accumulations.

- Confidence is increasing in the potential for accumulating
  snowfall Saturday into Saturday night, as models come into
  more agreement. Chances for at least an inch of snow are high
  (over 70%). Guidance still varies on where the heaviest 
  snowfall may fall. If you have travel plans, keep an eye on 
  the forecast.

- Cold, below normal temperatures are expected to continue
  through the weekend, with signs of temperatures moderating
  closer to normal next week.

&&

.DISCUSSION...
Issued at 301 AM CST Thu Dec 4 2025

TODAY: Surface high slides east through this morning. Guidance 
continues to handle stratus poorly west of the James River, which 
has been moderating temperatures somewhat in this area. 2 AM 
temperatures are below zero for most, with wind chills in the teens 
to mid 20s below. Still may see some locations east of I-29 briefly 
drop below Cold Weather Advisory criteria, but have remained 
headline free given marginal and brief conditions. We should warm 
into the teens (east) to mid 30s (south central SD).

WAA increases today, and we'll see a tightening surface pressure 
gradient as well as increased mixing. This allows for a breezier 
day, with southerly winds gusting around 35 to 40 mph - strongest in 
our higher elevations of the Buffalo Ridge. Main concern with these 
stronger wind gusts will be the potential for blowing snow. Blowing 
snow could lead to locally reduced visibility and patchy slick spots 
so be prepared for changing conditions this afternoon and evening.

TONIGHT-FRIDAY: Raised pops and QPF from the NBM with guidance 
coming into better agreement with light precipitation thanks to a 
stronger mid level wave and a surface boundary moving through the 
area after midnight and into Friday. However, there are still some 
questions regarding how much we'll saturate the column and in the 
DGZ, so could see some light freezing rain or freezing drizzle. 
Light precipitation looks to be largely be focused along and north 
of I-90 into northwestern IA. Any accumulations through the day 
Friday and into Friday night remain light, less than half an inch. 
Lows tonight fall into the teens and 20s with highs Friday in the 
30s.

SATURDAY-SATURDAY NIGHT: Models are coming into more agreement with 
a stronger wave/trough swinging through the central Plains Saturday 
into Saturday night. The 04.00 GFS/NAM remain the furthest south 
with the precipitation, while the Canadian is further north and the 
ECMWF is in the middle. Differences seem to largely be from where 
the surface warm front and moisture advection end up. The increased 
agreement is now reflected in the ensemble data as well, with a 
significant increase in the chances for a tenth of an inch of 
precipitation from 15-35% with the 03.00z runs to 55-85% with the 
04.00z ensemble data. Similar increases can also be seen in the 
potential for more than 0.25" during the same period. Again, there 
are still varied in the location of the heaviest precipitation, but 
certainly watch the forecast if you have travel plans. Chances for 
an inch of snowfall are high (over 65%), and for 2" inches are 
moderate to high (40-70%). Chances for greater than 4" of snow are 
low (less than 30%). However, this may still change.

Much colder air returns Saturday night with lows below zero.

SUNDAY: Much colder air continues region Sunday with high pressure 
returning. Highs may not exceed the single digits east of I-29, with 
the teens elsewhere. Some guidance shows brief but light snow 
Sunday, but confidence is low in this potential. Another cold night 
Sunday night, in the single digits either side of zero.

MONDAY-MID WEEK: Northwesterly flow regime keeps a more active 
pattern in place early to mid next week. Strongest wave is currently 
progged to move through Tuesday night into Wednesday, which could 
bring light precipitation back to the region. Details are uncertain. 
Regardless, below to near average temperatures continue through mid 
week. 

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1045 PM CST Wed Dec 3 2025

Current satellite imagery continues to show MVFR stratus sitting 
along and west of the James River. Low level flow is turning 
southerly/westerly, keeping the stratus from sinking south. With 
southwest/west low level flow in place, the stratus has began a 
crawl to the east. As such, have included MVFR ceilings for KHON for 
the entire night. Will monitor the stratus's trends through the 
night in case to see if any amendments will be needed. But 
currently thinking has the stratus breaking up around daybreak. At 
the surface, high pressure is passing through the area, turning 
northwest winds ahead of it to out of the south in its wake. These 
southerly winds will persist through the morning hours and even turn 
a bit more to out of the southwest by the afternoon hours. Winds 
will strengthen much more for the afternoon time frame as well with 
gusts up to 20-35 knots expected. The strongest winds will reside 
along the Buffalo Ridge in southwest Minnesota. Winds will slowly 
wane through the rest of the period but some low level wind shear 
(LLWS) is expected for the end of the period at KSUX.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.

&&

$$

DISCUSSION...SG
AVIATION...Meyers