sd discuss
Office: FSD
FXUS63 KFSD 070946
AFDFSD
Area Forecast Discussion
National Weather Service Sioux Falls SD
346 AM CST Sun Dec 7 2025
.KEY MESSAGES...
- Winds chills as cold as -20 degrees will continue through
mid-morning mainly across southwestern MN.
- Additional chances for light snow are expected this afternoon
and evening with accumulations of an inch or less expected.
- A parade of waves will move through the region during the
week ahead, bringing snow risks on both Tuesday and Thursday.
The most impactful snow system to watch may be on Thursday.
- Confidence is growing that winds Tuesday night into Wednesday
may break or exceed the 40 mph mark. We'll need to monitor the
snow pack and air temps closely to monitor blowing snow
potential.
&&
.DISCUSSION...
Issued at 342 AM CST Sun Dec 7 2025
TODAY & TONIGHT: Another cold day ahead! Taking a look across the
area, any lingering flurries continue to gradually dissipate this
morning as a surface high approaches from the northwest. From here,
a cold start to the morning is expected as a fresh snowpack and
lingering cold air advection (CAA) help most areas start on either
side of zero temperature-wise. Combine this with marginally breezy
northeasterly winds and the setup is primed for even colder winds
through mid-morning with values as low as 20 degrees below zero.
While this will mostly affect southwestern MN, make sure to bundle
up if you have any morning activities. Otherwise, quieter conditions
will persist for the first half of the day as temperatures peak in
the positive single digits to low 20s. Looking aloft, a quick mid-
level wave will closely follow the departing surface high leading to
additional chances for light snow during the afternoon to evening
hours. However, unlike with our previous system; amounts will likely
be on the lighter side with additional accumulations of 1 inch or
less expected. Lastly, as temperatures fall into the single digits
to teens overnight; could see the return of below zero wind chills
in southwestern MN to start the day on Monday.
MONDAY-WEDNESDAY: Looking into the new week, quieter conditions
temporarily return by Monday as northwesterly flow continues aloft.
With the return of southerly surface winds and increasing mid-level
warm air advection (WAA), temperatures will rebound towards the 30s
to low 40s for the day with the warmest conditions across southcentral
SD. Looking aloft, the wave train will continue across the northern
plains as northwesterly flow ushers in multiple waves through Wednesday.
The first clipper wave will dives across parts of northern MN by Monday
afternoon passing just north of us. A second and more robust clipper
wave will dive across portion eastern ND and central MN by Tuesday.
While most of the better dynamics will likely stay north of us, areas
north of I-90 will likely get enough of lift from the base of the
trough to get increased precipitation chances (30%-50%). However,
with temperatures trending more mild with highs in the upper 30s
to low 50s for the day; most of this should fall as rain.
Nonetheless, can't rule out an eventual transition to light snow on
the backside of the system as temperatures fall overnight. One thing
worth noting is the tightening SPG with the clipper will likely lead
to strong winds with gusts of 40+ mph from Tuesday night into
Wednesday. Depending on how the previous systems have affected our
snowpack, we could see areas of blowing/drifting snow developing
through Wednesday morning. Nonetheless, this will be something to
watch moving forward. From here, a third mid-level wave will swing
through by Wednesday morning along with its associated cold front.
While there won't likely be much precipitation associated with this
system, the strong blast of arctic air will decrease our temperatures
going forward with highs mainly in the teens to 20s for most areas.
Lastly, while some key details are uncertain; mid-range guidance
is starting to pick up on the potential for additional snow from
Wednesday night into Thursday as another quick clipper swings
through the area. With this in mind, make sure to monitor your
local forecast as this would the period to monitor the most.
THURSDAY ONWARDS: Heading into the extended period, its more rinse
and repeat. Periods of snow will continue for most of the day on
Thursday before tapering off. A surface high moves through the area
by Friday to replace the previously mentioned system. By Saturday
and Sunday another approaching clipper brings the potential for more
snow across the area. Lastly, temperatures will hover near to just
below normal with the coldest conditions expected on Friday and
Saturday as highs peaking the single digits to mid teens.
&&
.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1054 PM CST Sat Dec 6 2025
Light snow lingers for portions of east central South Dakota and
southwestern Minnesota. Snow will continue to dissipate becoming
very light flurries that may continue through midnight. There has
been brief instances of freezing rain/drizzle as snow is
dissipating. However, confidence of impacts to any one site is low,
and have left mention out of the TAF.
A secondary area of light snow is expected to move from north
central into southeastern South Dakota. This is expected to be
very light with light winds. Due to the this have opted to use a
tempo group for KHON.
Mostly IFR to MVFR ceilings will gradually improve through the
overnight to MVFR to VFR. However, the break will be short as
another fast moving snow shower moves in from the southwest Sunday
afternoon. This will move quickly northeast through the region,
producing light snow through the end of the period. Light northerly
winds will gradually become southeasterly through the day
Sunday.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.
&&
$$
DISCUSSION...05
AVIATION...AJP
Office: UNR
FXUS63 KUNR 070459
AFDUNR
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
959 PM MST Sat Dec 6 2025
.KEY MESSAGES...
- Light snow continues tonight through tomorrow morning
- Confidence is increasing for a High Wind Event to impact much of
western South Dakota on Tuesday. Could see wind gusts up to 70
mph
- Widespread precipitation expected on Wednesday. There is a low
end chance for various precipitation types across the eastern
plains (rain/freezing rain and a rain/snow mix)
&&
.DISCUSSION...(This Evening Through Saturday)
Issued at 106 PM MST Sat Dec 6 2025
Rest of today...Embedded in the persistent NW flow aloft a fast
moving shortwave is moving through the area this afternoon. Clouds
have increased in response with much of the region now under a low
cloud, overcast sky. Lingering moisture should be enough to
squeeze out some very light snow showers/flurries across eastern
Wyoming, western South Dakota and across the Black Hills this
afternoon and into Sunday morning. Expecting very little
accumulation with the higher peaks seeing maybe one inch, with the
valleys only seeing a trace amounts of snow. Whatever snow is out
there will diminish Sunday afternoon but with the cloud cover
sticking around, temperatures won't warm too much on Sunday with
highs predominately in the upper 30s to low 40s across the Black
Hills and adjacent foothills. Expect the coldest temperatures out
across the easter plains where highs will be in the low 30s.
Monday will be the only quiet day as we wait on the arrival of a
fast moving cold front associated with a strong area of low
pressure diving south out of North Dakota.
Confidence is increasing for a High Wind Event to impact much of
western South Dakota on Tuesday. A fast moving and deepening low
pressure system will dive south through central North Dakota and
quickly race to the south throughout the day on Tuesday. Winds
aloft with this system are currently (latest model run) between
50-60 knots. The winds will be be backed by a fast moving cold
front with very strong cold air advection into the region and
rapid pressure rises will aid in mixing down these winds aloft to
the surface. Soundings are showing ~58 knot winds just above the
surface across NW South Dakota. If this pattern holds, High Wind
Watches will be issued potentially as soon as early Monday
morning. Current forecast calls for winds to approach 70 mph
across the NW corner of South Dakota with strong winds between
55-65 mph impacting the foothills and eastern Plains through much
of Tuesday afternoon. Additionally, strong WAA will have streamed
into the region ahead of this system and with the compressional
heating often associated with these dynamic and fast moving
fronts, and the downslope wind component, temperatures could reach
into the 60s before the front moves through.
Wednesday another wave moves through the region and this one may
be tricky in determining the P-type across some of the Black Hill
foothills and eastern Plains. CAA will be working in from the
east but surface winds out of the south and southeast will keep
low level temperatures warm with the arrival of the best QPF.
Aloft temperatures will be cooling so profiles are hinting at the
very slight chance for some freezing rain to impact portions of
the eastern Plains on Wednesday. These types of events require a
lot of parameters coming together, but there is a slight signal
and freezing rain does bring significant impacts, so this is
something we will be watching in the coming days.
&&
.AVIATION...(For the 06Z TAFS Through 06Z Sunday Night)
Issued At 956 PM MST Sat Dec 6 2025
Light snow and patchy freezing fog are causing widespread
MVFR/IFR and LCL LIFR conditions across northeastern WY into
western SD. These conditions should continue through the rest of
tonight into early this morning. Conditions should improve to VFR
from west to east after ~16-18z.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&
$$
DISCUSSION/KEY MESSAGES...Woodward
AVIATION...Wong
Office: ABR
FXUS63 KABR 070922
AFDABR
Area Forecast Discussion
National Weather Service Aberdeen SD
322 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.
&&
.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 /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1114 PM CST Sat Dec 6 2025
Terminals KABR,KATY,KPIR,KMBG
MVFR cigs are exiting to the south this evening. Expect MVFR cigs
to move in from west to east Sunday as another round of light snow
moves through the region.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
SHORT TERM...BC
LONG TERM...10
AVIATION...20
