573
FXUS63 KABR 261830 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1230 PM CST Fri Dec 26 2025

.KEY MESSAGES...

- Areas of fog will remain possible through this evening across
  northern portions of the region. Dense fog and temperatures
  below freezing could create pockets of freezing fog with icy
  roads.

- Above normal temperatures will continue through the daytime
  hours Saturday, before falling mainly into the teens to single
  digits above zero Sunday morning through Monday evening.

- A prolonged period of winds out of the northwest will gust around
  40 to 50 mph late Saturday evening through the day Sunday.

&&

.UPDATE...
Issued at 1226 PM CST Fri Dec 26 2025

Aviation discussion updated below for the 18Z TAFs.

UPDATE Issued at 1017 AM CST Fri Dec 26 2025

Continue to monitor web cams and obs across the region in regards
to fog trends over central/north central SD and across northeast SD
into west central MN. Still seeing areas of dense fog in portions
of the current advisories and have actually extended the eastern
segment across northeast SD into early afternoon (while also
chopping a few counties). Adjusted grids/forecast to better
reflect satellite trends in regards to sky/wx.

&&

.DISCUSSION...
Issued at 413 AM CST Fri Dec 26 2025

Patchy to dense fog will remain possible through this evening. Dense
fog and temperatures below freezing could create pockets of freezing
fog with icy roads this morning. The light rain that fell from from
the passing surface trough is also adding to the icy sidewalks and
roadways.

The abundant low level moisture with patchy to dense fog remains a
concern, and will continue to be a concern into Saturday. Winds will
remain light today, with the surface currently ridge stretching from
northern Alberta and central Saskatchewan through central ND
shifting along the ND/SD/MN border by 18Z and across MN/IA this
afternoon. Winds will increase out of the south over central SD this
afternoon, helping to mix/erode the the thicker fog and shift it
north. The mention of freezing fog will continue from north central
to northeastern SD, especially near the ND/SD border into Saturday
as temperatures remain at or below freezing. High temperatures today
will be the 30s, except into the 40s west of the Missouri River and
over south central South Dakota. Temperatures will stay mainly in
the 30s tonight, and rise into the upper 30s and 40s Saturday
afternoon. Normal high temperatures his time of year are in the 20s,
and in the low 30s south of Pierre. The surface low over MT into
southwestern SD will move over western and central SD by daybreak
Saturday.

The end to our above normal temperatures will come Saturday night,
as a cold front sinks southeast across the area, bringing colder and
breezy conditions. Temperatures will be mainly in the teens to
single digits above zero Sunday morning through Monday evening.

Behind the cold front, winds out of the north will shift out of the
northwest. Gusts of 40 to 50 mph will be possible late Saturday
evening through the day Sunday. The 50 mph values are near the NBM
90th percentile for this event, and highest over central SD. Fire
weather concerns return to the dry/snow-free areas of mainly central
SD. We are forecasting high grassland fire danger index values
Saturday afternoon over Jones County, where winds out of the west
gust to around 20 mph and relative humidity values fall to around 45
percent. High to Very High grassland fire danger index values are
then possible Sunday afternoon over all of central South Dakota.
This is where relative humidity values will fall to 40 to 60
percent, and winds will be in that 40-50 mph range gust wise. While
we do have around a 20 percent chance of light snow Saturday night
into Sunday morning, mainly dry weather is expected to continue. Any
precipitation will diminish fire weather concerns.

Wind chill values bottom out Sunday night into Monday morning around
-10 to -20F. At this point it doesn`t look like any cold weather
headlines will be needed for this system, as wind chills stay above
the -25 to -30F advisory levels.

Temperatures look to moderate back to near to above normal briefly
Tuesday, with highs mainly in the 30s to low 40s (highest over south
central SD). Variability increases significantly as we move into
Wednesday/Day 5 and beyond. Looking at the ensemble guidance, the
GEPS is near the low end temperature-wise, with the GEFS at the high
end, with the ENS in between the two. We`ll continue to monitor the
trends over the next few days, but expect changes to the forecast
for Wednesday and beyond. Fro example, at 12Z Wednesday the
difference for Aberdeen is -15F to +6F for temperatures.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1226 PM CST Fri Dec 26 2025

Terminals KABR,KATY,KPIR,KMBG

KPIR/KATY will see VFR conditions at the start of the TAF period,
while KMBG/KABR will be dealing with some BR (KMBG) and IFR CIGs.
Early on these CIGs are mainly affecting KMBG, but are nearby KABR
and a bit uncertain if they will move in this afternoon or not.
Regardless, indications point to a return of FG/BR overnight,
along with IFR CIGs.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Dense Fog Advisory until 3 PM CST /2 PM MST/ this afternoon for
     SDZ003>005-015.

     Dense Fog Advisory until 1 PM CST this afternoon for SDZ007-008-
     011.

MN...None.
&&

$$

UPDATE...TMT
DISCUSSION...06
AVIATION...TMT