sd discuss
Office: FSD
FXUS63 KFSD 061457
AFDFSD
Area Forecast Discussion
National Weather Service Sioux Falls SD
857 AM CST Sat Dec 6 2025
.KEY MESSAGES...
- A quick-moving winter system will bring mainly 3-6" of snow
for most areas along and east of the James River today.
Locally higher amounts over 6 inches will be possible around
the Iowa Great Lakes into the Jackson and Worthington,
Minnesota areas.
- Snowfall rates as high as 1-1.5" inches per hour within the
heaviest band axis during the afternoon to evening hours will
lead to rapid accumulations along and east of I-29. Visibility
reductions and hazardous road conditions will lead to minor to
moderate travel impacts at times affecting the evening commute.
- Cold wind chills will return each night through Monday with
values as cold as 20 below possible.
- An active pattern aloft will lead to multiple precipitation
chances through the work week. Continue to monitor the
forecast moving forward.
&&
.UPDATE...
Issued at 847 AM CST Sat Dec 6 2025
Radar echoes continuing to expand this morning and frontal band
currently remains in it's infancy stage. 12Z guidance continues
to confirm thoughts that as PV begins to pivot into South
Central South Dakota and Northern Nebraska, warm advection and
frontogenesis will intensify along a NW to SE axis through the
Tri-State area.
Soundings nearby the frontal band show persistent instability
sitting AOA the 700 mb layer, with MUCAPE anywhere from 10-30
J/KG residing along the MO River valley. Several of the 12Z CAMS
are picking up on this instability with simulated reflectivity
showing the convective elements feeding northeast by early
afternoon. Thus, have introduced a low end probability for
thunder along but especially south of I-90 for a few hours.
Totals generally remain on track with the previous forecast, but
have increased QPF slightly along what looks to be the favored
frontal zone. With the potential instability release, expecting
snowfall rates of 1.5" or more per hour in a handful of
counties. The increase of QPF will result in a corridor of 5 to
8" snow potential. Will extend the WSW a couple counties
westward, based on both snow amount, but also rapid worsening of
conditions this afternoon.
&&
.DISCUSSION...
Issued at 255 AM CST Sat Dec 6 2025
TODAY & TONIGHT: A dreary and cooler day ahead! Taking a look across
the area, mainly overcast skies continue this morning with most
areas sitting in the mid to upper 20s. Don't expect much change
during the day as overcast skies and slight breezy southeasterly
winds keep temperatures locked into the 20s to low 30s with the
warmest conditions along the Missouri River Valley. Taking a
look aloft, the forecast remains on track as a quick mid-level
wave dives across portions of South Dakota, Nebraska, and
Minnesota today bringing our next chances for snow. By daybreak,
should see light returns over central SD become more widespread
across southeastern SD as increasing dPVA and mid-level frontal
forcing interact with the WAA regime ahead of the surface
trough. From here, an enhanced area of snowfall should to begin
to take shape by late morning just south of the I-90 corridor in
southeastern SD and this should be the main driver of our
accumulations going forward. As this developing band of snowfall
gradually pivots southeastwards, HREF guidance continue to show
moderate to high confidence (60%-80%) in 1" in/hr or greater
snowfall rates which should lead to moderate to heavy
accumulations at times especially across far southeastern SD,
northwestern IA, and portions of southwestern MN.
With all of this in mind and collaboration with our neighbors,
decided to upgrade portions of our Winter Weather Advisory in
northwestern IA and southwestern MN into a Winter Storm Warning
where confidence was highest in 6+ inches of accumulations. While 3-
6 inches of accumulations continues to look like the most
likely range for most areas east of the James River, can't rule
out additional upgrades in far southeastern SD and southwestern
MN if the axis of heaviest snowfall shifts northwards or
southwards. Otherwise, should see most of the snow taper off by
late evening. Shifting gears to impacts, falling snow and rapid
accumulations will lead reductions in visibility and hazardous
travel mainly in the afternoon to evening hours. As a result,
minor to moderate travel impacts are expected especially in the
areas with the highest accumulations so be prepared to post-pone
travel plans where necessary! Looking into the rest of the
night, a fresh snowpack and lighter surface winds will lead to
much colder conditions overnight with lows being on either side
of zero. Nonetheless, wind chill will likely be even colder with
values as low as 20 below possible mainly across southwestern
MN.
SUNDAY ONWARDS: Looking ahead, a surface high will move in to
replace the departing system on Sunday. Unfortunately, so will
another mid-level wave. With this in mind, additional light
accumulations will be possible from Sunday night into Monday mainly
along and north of I-90. The cold air plunge will continue as well
with highs mainly in the single digits to low 20s. From here, the
active pattern aloft will continue for the rest of the week. By
Tuesday, a decently strong clipper wave will dive across the
northern plains bringing our next chances for precipitation.
However, increasing warm air advection (WAA) and southerly surface
winds ahead of this system will likely keep most of the
precipitation as rain or a rain/snow mix given temperatures in the
upper 30s to upper 40s. As long-range guidance starts to diverge
between Wednesday to Thursday, it looks like another clipper will
fly through the northern plains. However, there are still subtle
differences in the timing and placement of features. Lastly,
temperatures will continue to trend colder from Wednesday onwards
with highs mainly in the teens to low 20s.
&&
.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 540 AM CST Sat Dec 6 2025
A mix of VFR and MVFR conditions this morning will transition to
MVFR conditions and lower for the rest of the TAF period.
Looking at satellite imagery, MVFR stratus continues to blanket
the area this morning with upper level clouds moving overhead.
From here, areas of light snow across southcentral SD will
progress into our area throughout the day with light to moderate
accumulations expected. Falling snow could lead to periods of
IFR/LIFR vsbys along with IFR cigs from the lingering stratus.
Otherwise, southeasterly winds will back with the approaching
surface wave becoming more northerly to end the TAF period.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory until 9 PM CST this evening for SDZ040-
055-056-069>071.
Winter Weather Advisory until 6 PM CST this evening for SDZ038-
039-052>054-058>060-064-065-068.
Winter Storm Warning until 9 PM CST this evening for SDZ061-
062-066-067.
MN...Winter Storm Warning from noon today to midnight CST tonight
for MNZ089-090-098.
Winter Weather Advisory from noon today to midnight CST
tonight for MNZ071-072-080-081-097.
IA...Winter Storm Warning from noon today to midnight CST tonight
for IAZ001>003-012>014-021-022.
Winter Weather Advisory from noon today to midnight CST
tonight for IAZ020-031-032.
NE...Winter Weather Advisory until 9 PM CST this evening for NEZ013-
014.
&&
$$
UPDATE...Dux
DISCUSSION...05
AVIATION...05
Office: UNR
FXUS63 KUNR 061702
AFDUNR
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1002 AM MST Sat Dec 6 2025
.KEY MESSAGES...
- Chances for light snow today through Sunday morning.
- Warm and windy conditions early next week.
- More chances for precipitation for latter half of next week.
&&
.DISCUSSION...(Today Through Friday)
Issued at 309 AM MST Sat Dec 6 2025
Upper air analysis shows northwest flow continuing over the western
half of the CONUS, as it has been doing for some days now. A series
of embedded waves are crossing the northern Rockies into the
northern High Plains. At the surface, low pressure is developing
across southern MT through eastern WY, with breezy S/SE winds
responding across the western SD plains. KUDX radar shows light snow
gradually moving into the forecast area. The surface low will cross
SW/SCentral SD this morning as it strengthens, drawing colder air
back in from the NE. Light snow will continue today...mainly across
NW/central SD and the northern Black Hills. However, snow amounts
are expected to be light...an inch or less across most areas. Highs
will range from the mid 20s over NW SD to the lower 40s over far SW
SD. Snow will gradually dissipate this evening, but the next wave
and a warm front, will bring back more light snow to the area late
tonight through Sunday morning. Again, this could bring an inch
or so of snow, especially over NW SD and the northern Black Hills.
Lows will be in the single digits over NW SD and 20s over NE WY,
where warmer air will have worked in. Most areas will be dry by
Sunday afternoon, with highs in the 30s to lower 40s. Even warmer
air is expected on Monday as highs reach the 40s to lower 50s, along
with dry conditions. The next system then quickly pushes through
on Tuesday. Models have been showing highs even warmer than
Monday...approaching 60 in some spots. However, the ECM & GFS are
progged to bring a very strong cold front sometime in the afternoon,
which could affect highs if the timing ends up being earlier in the
day. Strong cold air advection and pressure rises could support
very strong winds, with gusts well over 60 mph. Will be keeping an
eye on this. The best chance for precip will again be over NW SD,
but would likely fall as rain, before the colder air can push in.
Active NW flow is progged to persist into the second half of the
week, with more unsettled weather, cooler temperatures, and breezy
winds.
&&
.AVIATION...(For the 18Z TAFS Through 18Z Sunday)
Issued At 1001 AM MST Sat Dec 6 2025
MVFR with local IFR conditions in -SHSN will develop this
afternoon. Though snow will end this evening, MVFR/IFR CIGS will
remain overnight and continue into the next round of snow early
Sunday morning.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&
$$
DISCUSSION/KEY MESSAGES...13
AVIATION...Smith
Office: ABR
FXUS63 KABR 061552
AFDABR
Area Forecast Discussion
National Weather Service Aberdeen SD
952 AM CST Sat Dec 6 2025
.KEY MESSAGES...
- Snow returns Saturday. 1 to 3 inches of accumulation is expected
through Saturday afternoon, with highest amounts expected in east
central South Dakota. A Winter Weather Advisory remains in effect
for parts of east central South Dakota.
- There will be periodic lower chances for precipitation (20-40%)
beginning Sunday and continuing through early next week, as more
weak weather systems have the potential to move through the region.
- Strong northwest winds of 20 to 35 mph with gusts in excess of 45
mph are a concern from late Tuesday afternoon through Wednesday
morning.
&&
.UPDATE...
Issued at 949 AM CST Sat Dec 6 2025
Band of moderate intensity snow has set up from just south of
Mobridge to Faulkton, Miller and Redfield. This feature is sitting
and pivoting with a slow motion eastwards. Increased snowfall for
under the band and added Faulk and Hand to the winter weather
advisory given snowfall rates evident on Kelo and DOT cams.
&&
.SHORT TERM /TODAY THROUGH SUNDAY AFTERNOON/...
Issued at 258 AM CST Sat Dec 6 2025
Main focus in the near-term period continues to be the incoming low
pressure center that is expected to bring precipitation to the
forecast area. Ensemble means currently show between 0.10"-0.20" of
liquid equivalent precipitation through Saturday evening. Model
soundings indicate that snow will be the dominant precip type, and
there will be little chance for anything else due to temperatures at
both the surface and aloft expected to remain below freezing through
the event. Expected snow ratios are around 15:1 based on model
soundings, which will translate to around 2" across the forecast
area. The highest totals are expected over eastern South Dakota,
where NBM 90th percentile values are around 3 inches. No changes
have been made to the Winter Weather Advisory, in effect from 9 AM
to 6 PM CST for Spink, Clark, Hamlin and Deuel counties, where the
accumulations are expected to be highest. Timing wise, the highest
QPF totals are expected Saturday morning and afternoon, before
tapering off Saturday evening.
With this system, the winds bring an additional element to the
forecast. Gusts up to 30 miles per hour are anticipated between the
James River and the Missouri River this afternoon. The timing of
these winds will most likely be after the peak precipitation time in
that area, so impacts may be marginal. However any falling snow or
potentially the fresh snow on the ground could be moved around by
the wind and potentially reduce visibility and make travel dangerous
at times. Winds will not be strong enough nor will snowfall rates be
heavy enough for any widespread blowing snow impacts, and anything
that does come together will be isolated.
Behind Saturday's system, another clipper comes down into the
forecast area Sunday and will bring additional snow to northern
South Dakota. Only a few hundredths of liquid equivalent are
expected, mainly during the daytime hours. This will translate to
about a half an inch in additional accumulation, with fairly broad
coverage across north central and northeastern South Dakota. NBM
90th percentile (as a proxy for a "worst-case" scenario) for this
event only reaches pockets of 1" in additional accumulations, so it
is safe to say this will be a fairly low-impact snow event on
Sunday.
&&
.LONG TERM /SUNDAY EVENING THROUGH FRIDAY/...
Issued at 258 AM CST Sat Dec 6 2025
When the period opens Sunday evening, light snow is expected to be
still falling across the eastern half of the CWA, working its way
east into Minnesota. The flow pattern compared to 24 hours ago has
not changed, a positive PNA pattern of upper ridge over the western
CONUS and upper trof over the eastern CONUS, placing this CWA in
northwest flow aloft. Models maintain that several transient areas
of clipper-like low pressure will move through the northern plains
in this upper level steering flow.
Initial low level WAA setting up over the CWA on Monday is fairly
strong, lingering into Tuesday before a strong cold front sweeps
through. High temperatures on Monday warm up into the 30s and 40s
across much of the CWA, despite snow on the ground. Tuesday could be
even warmer, with highs in the upper 30s to lower 50s thought
possible prior to Tuesday's strong cold frontal passage. Strong
winds at 0.5km and higher are not expected to be felt at the surface
during the warm up on Monday. When the second surge of strong winds
in the warm sector kick in on Tuesday, there is expected to be a
period in the mid to late afternoon through the overnight hours
Tuesday night when sustained winds could exceed 40 mph and gusts
could exceed 58 mph. ENS EFI wind gusts signal is beginning to latch
on to the potential for strong wind now for Tuesday afternoon/night.
Will continue to monitor wind forecast trends, but a High Wind Watch
may be needed within the next couple of days for Tuesday/Tuesday
night. In addition to the potential for strong winds, there is some
potential for rain on Tuesday (20-40 percent chance of a quarter
inch or more of water equivalent precipitation north of a line from
Leola to Milbank. The potential for a little bit of freezing or
frozen precipitation p-type also clings to the far
northern/northeastern forecast zones Tuesday into Tuesday night,
although, still seeing a signal for the heaviest, most
meaningful/hazardous precipitation potential to reside across North
Dakota into Minnesota right now for Tuesday/Tuesday night. Arctic
cold air floods into the region from the north for Wednesday through
the end of the period. Additional chances for precipitation (snow p-
type) show up Wednesday night into Thursday.
&&
.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 505 AM CST Sat Dec 6 2025
Terminals KABR,KATY,KPIR,KMBG
The main aviation concern today will be the incoming low pressure
center bringing snow to the region. Snowfall rates are generally
expected to be light, but will still likely drop visibility down to
MVFR and even IFR status at times. Similar drops in the ceiling can
be expected, and in all likelihood the airspace will be jumping
between MVFR and IFR conditions through the day. The addition of
wind adds another complication, because when coupled with the
falling snow, it may reduce visibility even further. The strongest
gusts will be between the Missouri River and the James River, up to
25 knots in the afternoon. Where winds are strongest, there may be
isolated areas of drifting or blowing snow, which could potentially
drop visibility as low as LIFR status at times. Snowfall will be
heaviest this afternoon, with eastern South Dakota expected to see
the highest snowfall rates. Snow will taper off this evening, but a
few light lingering showers may persist past sundown. MVFR ceilings
are expected to stick around after the snowfall moves out and
through nearly the rest of the TAF period, eventually lifting back
to VFR overnight.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory until 2 PM CST this afternoon for SDZ017-
037.
Winter Weather Advisory until 6 PM CST this evening for SDZ018-
019-022-023.
MN...None.
&&
$$
UPDATE...07
SHORT TERM...BC
LONG TERM...10
AVIATION...BC
