985
FXUS63 KABR 071113
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
513 AM CST Sun Dec 7 2025

.KEY MESSAGES...

- A band of light snow moves west to east today. Less than an inch
of accumulation is expected with this system.

- Northwest winds Tuesday afternoon into late Tuesday evening could
gust in excess of 55 mph.

- Some of the coldest air of this winter season could be settling
over the area by the end of the week, including high temperatures
around or slightly above 0F and low temperatures down into the
single digits below to teens below zero and wind chill values Friday
morning as low as -20F to -35F.

&&

.UPDATE...
Issued at 512 AM CST Sun Dec 7 2025

Aviation discussion below has been updated in accordance with the
12Z TAF issuance.

&&

.SHORT TERM /TODAY THROUGH MONDAY AFTERNOON/...
Issued at 306 AM CST Sun Dec 7 2025

Only a short break in precipitation is expected as the next round
moves in central and north central South Dakota beginning this
morning. This precip will be supported by a jet streak aloft, which
will traverse eastward through the day this afternoon and evening,
bringing the precip with it. Snow is expected to be the main
precipitation type through the event, but there is minor potential
for a transition to freezing rain this evening. This would occur due
to the upper-levels de-saturating, potentially to the point at which
temperatures in the saturated layer could be warm enough to support
liquid accumulation aloft. Luckily model guidance shows this would
be on the very back end of the system as precip is moving out,
meaning that the greatest source of lift will be out of the area and
precip rates would be lower. With this being such a marginal
possibility, no significant freezing rain potential has been added
to the gridded forecast, but also would not be surprised to see it
if all the variables come together perfectly. Precipitation is
expected to exit northeastern South Dakota around midnight tonight
at the latest.

In total with this system, only a few hundredths of liquid
equivalent are expected, translating to less than an inch of snow
across the area. Looking at the latest NBM 90th percentile as a
reasonable "worst case" value, QPF values sit around a tenth of an
inch. This would translate to between 1"-2" in accumulation. It is
worth noting that under a similar pattern yesterday, snow ratios
were quite high, so it is possible that we once again will
overachieve and come closer to that 90th percentile snowfall.

Monday offers a bit of a reprieve from the snow, and conditions are
expected to be dry through the day. Another shortwave supporting a
low pressure center will come off the upper-level ridge, but this
time it will stay to the north of the Aberdeen CWA. The track of the
low will allow temperatures to warm up a bit, particularly over
central South Dakota. Highs tomorrow are expected to reach the 40s
in that area (about 10 degrees above normal for mid-December), with
highs decreasing down to the low-30s as you move into northeastern
South Dakota. Areas west of the James River are expected to see
highs above freezing, so partial to full melting of the snowpack
will likely occur.

&&

.LONG TERM /MONDAY EVENING THROUGH SATURDAY/...
Issued at 306 AM CST Sun Dec 7 2025

When the period opens Monday night, in the middle of a low level WAA
event. Much above normal temperatures are expected to persist into
Tuesday, with precipitation developing/working west to east across
the CWA, particularly north of U.S. Highway 212. Surface
temperatures may be at or below freezing to start Tuesday morning,
but within a few hours of sun-rise Tuesday, surface temperatures on
an efficient westerly mixing layer wind should be warming things up
to above freezing while precipitation potential persists. So, the
forecast contains a few hours of freezing rain mention before
transitioning to rain potential for the rest of the day.

The clipper system bringing the warm air and precipitation chances
on Tuesday will sweep a strong cold frontal passage through the CWA
Tuesday afternoon through late Tuesday evening. The combination of
already quite strong winds at 0.5km with strong low level CAA and a
strong pressure rise/tendency heading into early Tuesday evening
supports the potential for headlineable winds. Still too soon to
issue a wind headline for Tuesday afternoon/night. But, it is being
monitored closely. Not for a blowing snow concern, given all the
melting and rain that will have fallen during the day on Tuesday,
crusting any remaining snowcover. But, strength of winds may make
for rather hazardous traveling conditions. If there is any post cold
frontal falling snow to be had across northeast South Dakota Tuesday
night, that area could actually see some blowing snow/reduced
visibility late Tuesday night into early Wednesday morning.

Still more chances for precipitation showing up, potentially
Wednesday night into Thursday morning and again by Saturday. Staring
to approach 2 standard deviations below normal for 850hpa
standardized temperature anomalies in the ENS S.A. data table for
Friday. Ensemble-powered forecast low temperatures Thursday night
are below zero (0F to ~ -12F) and high temperatures Friday range
from ~ -3F to 12F, with Friday night lows dipping down below zero (~
-2F to -15F) again. Wind chill values are forecast to fall to
between -20F to -35F heading into Friday morning while winds are
forecast to be 10 to 20 mph sustained with gusts up to 30 mph
possible. Simply brutal conditions, that are being monitored for a
potential "cold weather" headline.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 512 AM CST Sun Dec 7 2025

Terminals KABR,KATY,KPIR,KMBG

Another round of snow will move into central and north central South
Dakota this morning, expanding east through the day today. Snowfall
rates are expected to remain fairly low, but will still be enough to
reduce visibility at times. Generally MVFR visibilities can be
expected where snow is present, with an occasional dip down to IFR
visibilities. The same can be said for ceilings, as the main cloud
deck will be MVFR with occasional IFR conditions. Snowfall will move
out of central/north central South Dakota by this evening and out of
northeastern South Dakota tonight. There is some potential for
lingering light snow on the back end of the system, so have left a
PROB30 group in the TAFs for the ending of the precipitation. MVFR
ceilings will also linger on the back end of the system, moving out
from west to east near the end of the TAF period Monday morning.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&

$$

UPDATE...BC
SHORT TERM...BC
LONG TERM...10
AVIATION...BC