sd discuss
Office: FSD
FXUS63 KFSD 052106
AFDFSD
Area Forecast Discussion
National Weather Service Sioux Falls SD
306 PM CST Fri Dec 5 2025
.KEY MESSAGES...
- A quick-moving winter system will bring mainly 3-6" of snow
for areas along and east of the James River Saturday into
Saturday night. Locally higher amounts over 6 inches looks
possible mainly in and around the Iowa Great Lakes into the
Jackson, Minnesota area.
- Snowfall rates could be as high as 1-1.5" an hour in the
heaviest snow especially Saturday afternoon and early evening,
which would cause visibility reductions and quickly
accumulating snowfall. Be sure to use extra caution on the
roads and prepare for potential travel delays.
- Cold wind chills move in once again Saturday night, with wind
chills down to the -5 to -15 degree range by Sunday morning.
- Near to below normal temperatures will continue into the new
week with the next chances for precipitation possible on
Tuesday.
&&
.DISCUSSION...
Issued at 302 PM CST Fri Dec 5 2025
It was a much warmer day out there today compared to yesterday,
with highs into the 30s area-wide. Spotty snow and rain showers
continue to push across the area, but we should dry out heading
into tonight. Temperatures will drop tonight behind a weak
frontal boundary into the lower 10s to lower 20s, so a chilly
night is ahead. This will set the stage for our next snowmaker
set to impact the area during the day Saturday into Saturday
evening. A band of snow looks to develop off to our west around
daybreak Saturday and push eastward into our area. Snow should
begin around sunrise west of the James River, by the late
morning/early afternoon time frame for the I-29 corridor, and
then spread into the rest of northwest Iowa and southwest
Minnesota through the afternoon. Due to the later start time
expected for the I-29 corridor, did move the start time up for
the Winter Weather Advisory there to begin at 9 am Saturday.
Snow should wrap up from west to east through the evening hours.
This is slightly slower than what guidance was showing
overnight, so opted to extend the Winter Weather Advisory for
northwest Iowa and southwest Minnesota until midnight Saturday
night/Sunday morning.
Unlike our last winter storm, which was more of a slowly
developing system, this one will be quick moving with higher
snowfall rates, potentially up to an inch to inch and a half per
hour at times especially in the afternoon and early evening
hours. This means snow will accumulate quickly after it begins
and visibility will be reduced. Speaking of accumulations, we
look to generally see around 3-6" along and east of the James
River. West of there, amounts looks to be in the 1-3" range. The
highest snowfall totals will be in and around the Iowa Great
Lakes to the Jackson, MN area, where locally 6-7 inches of snow
will be possible. Opted to not upgrade to a Winter Storm Warning
for these areas for two reasons. One, amounts of at least 6
inches or more are expected to remain isolated at this time, and
without excessive wind to blow things around, we won't be
anywhere near whiteout concerns or anything like that. Second,
guidance has been a bit inconsistent on where the heaviest
snowfall rates will end up, with some guidance indicating this
heavier band setting up either along the I-90 corridor in
southwest Minnesota, or over portions of northwest Iowa, or
even into central Iowa (out of our county warning area). Future
upgrades may be necessary if guidance either starts to signal
more widespread 6+ inch totals or if guidance comes into better
agreement, so keep up to date with the latest forecast! Either
way, extra caution should be used on the roadways on Saturday.
From there, we get colder, with temperatures Saturday night dropping
to the single digits on either side of zero. Wind chills look to be
in the negative 5 to negative 15 degree range by Sunday morning.
Highs on Sunday only look to be mostly in the single digits to low-
10s, perhaps slightly warmer where less snowpack is expected (south-
central SD). Temperatures look to moderate heading into the next
work week, with temperatures rising above freezing across the entire
area by Tuesday. Another storm system will move in Tuesday into
Tuesday night. With the warmer temperatures in place, there's a
chance this system starts out as all rain, with perhaps a changeover
to snow on the backside of the system. Details remain uncertain as
it will come down to the track of the system, which this many days
out is highly uncertain. Either way, temperatures look to cool off
below normal again after this system moves through.
&&
.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1139 AM CST Fri Dec 5 2025
Scattered rain and snow showers (with some freezing rain and sleet
mixed in) continues to move from northwest to southeast across the
area. Guidance is doing a poor job handling the precipitation, but
it does look to remain hit or miss in nature heading into the
afternoon. So there will be chances for precipitation (mainly a
rain/snow mix) at the terminals through the afternoon and early
evening. We'll get a period of dry weather overnight before our next
round of precipitation arrives, which is expected to be
all snow at this time. A band of snow looks to develop over
central South Dakota around daybreak tomorrow morning and move
eastward through the morning, reaching the terminals during the
last few hours of the period. MVFR visibilities are expected
with the snow initially, but heavier snow rates will likely
arrive just after this TAF period.
CIGS will be a mix of IFR and MVFR through the period, with some
scattering out of the lower cloud deck at KSUX around midnight
tonight before filling back in tomorrow morning. Expect IFR CIGS
when tomorrow's round of snow arrives at the terminals. Winds this
afternoon will be out of the northwest around 8-12 kts, higher in
south-central South Dakota up to 12-18 kts. Winds turn light and
variable tonight and look to pick up again through tomorrow morning
out of the east-southeast.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory from 9 AM to 9 PM CST Saturday for
SDZ040-055-056-061-062-066-067-069>071.
Winter Weather Advisory from 6 AM to 6 PM CST Saturday for
SDZ038-039-052>054-058>060-064-065-068.
MN...Winter Weather Advisory from noon Saturday to midnight CST
Saturday night for MNZ071-072-080-081-089-090-097-098.
IA...Winter Weather Advisory from noon Saturday to midnight CST
Saturday night for IAZ001>003-012>014-020>022-031-032.
NE...Winter Weather Advisory from 9 AM to 9 PM CST Saturday for
NEZ013-014.
&&
$$
DISCUSSION...Samet
AVIATION...Samet
Office: UNR
FXUS63 KUNR 052305
AFDUNR
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
405 PM MST Fri Dec 5 2025
.KEY MESSAGES...
- Chances for light snow return Saturday/Sunday.
- Warm and windy conditions early next week.
- More chances for precipitation latter half of next week.
&&
.DISCUSSION...(This Evening Through Friday)
Issued at 157 PM MST Fri Dec 5 2025
An upper air analysis shows northwest flow continuing over the
northern plains today. Surface chart depicts weak frontal boundary
stretching from southeastern MT down into southeastern SD.
Temperatures currently sit in the mid 30s to low 40s, with light
to breezy northwesterly winds. Radar shows some very light spotty
returns running southeast along or near the boundary, though
webcams show nothing coming down.
Surface high pressure moves in behind the boundary this evening,
bringing in a brief dry period before the next disturbance.
Isentropic forcing will increase ahead of the low over south
central SD, then quickly move southeast of the CWA. Northerly flow
behind the low will reinforce the colder air and will be the
focus for precip Saturday and Saturday night. The main forcing and
areas for accumulating snow will be in northwestern SD and the
enhanced upslope northern Black Hills regions for Saturday and
Sunday. Some areas in the northwestern SD plains could see 1-3
inches, while the northern Black Hills seeing slightly higher
amounts in the 2-5 inch range. Minor impacts in the hills maybe
possible, however likely not enough to warrant a headline.
Early next week upper high over the southwestern Pacific
strengthens, promoting weak ridging over the western CONUS. This
will result in a warming trend for Monday/Tuesday. Warmest day of
next week will be Tuesday, with highs reaching into the upper 40s
over northwestern SD, to the upper 50s near I-90 and south. There
is some model divergence for the latter half of next week, but
there is a signal for more active weather and cooler temperatures
returning.
&&
.AVIATION...(For the 00Z TAFS Through 00Z Saturday Evening)
Issued At 403 PM MST Fri Dec 5 2025
MVFR/LCL IFR conditions with -SN will develop from west to east
after 06z tonight and continue into tomorrow morning. Winds will
shift from the south to the northwest after 12z with gusts of up
to 25kt.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&
$$
DISCUSSION/KEY MESSAGES...Dye
AVIATION...Wong
Office: ABR
FXUS63 KABR 051903
AFDABR
Area Forecast Discussion
National Weather Service Aberdeen SD
103 PM CST Fri Dec 5 2025
.KEY MESSAGES...
- Snow returns Saturday. 1 to 4 inches of accumulation is
expected, with highest amounts south of Highway 212 in east central
SD.
- There will be periodic lower chances for precipitation (20-40%)
through early next week, as more weak weather systems have the
potential to move through the region.
&&
.DISCUSSION...
Issued at 103 PM CST Fri Dec 5 2025
The pattern will remain active through the middle to end of the
upcoming week. The region will mostly stay in an upper trough but
will continue to have numerous shortwaves rotating through the upper-
level flow. These shortwaves will bring periods of light snow and
potentially mixed precipitation through next Thursday.
Most of today's precipitation has exited the region, however there is
still a mix of light snow and freezing drizzle in west central MN
early this afternoon. Colder air has also backdoored into the
northeast, causing temperatures to fall about 5 degrees since this
morning. Surface low moves through NE on Saturday. This combined
with a shortwave over SD will produce some light snow starting early
in the morning across central SD and moving east through the day. A
Winter Weather Advisory has been issued for portions of east central
SD where higher QPF has pushed farther north in latest model runs.
Generally expecting 2-4 inches south of HWY 212, with lower amounts
farther north and west. Snow showers may linger well into the
evening on the backside of the surface low.
Arctic high pressure builds into eastern SD Saturday night into
Sunday when highs may only be in the single digits east of the James
Valley. Return flow behind the high as well as an upper ridge
building east into the Plains will see temperatures rebound into
Monday as highs climb into the 40s in central SD. The warmer air
Sunday night along with a passing shortwave could result in some
additional light snow. On Tuesday, low pressure remains to the north
with main impacts across ND and MN. Will need to keep an eye on this
one as any southerly drift in the track of the low could
significantly change expectations. Wednesday night into Thursday has
the potential for more warm air advection banding with the low
pressure heading over SD and NE.
From Saturday evening through the end of the period, the over-
arching flow pattern theme remains "positive PNA". Northwest flow is
still lining up transient clipper-like shortwaves over the region,
each one separated from the next by roughly 24 hours.
With the active pattern of low pressure systems working through, the
low level thermal advection pattern will be pretty busy. Weak low
level CAA is happening Saturday night into Sunday morning, but low
level WAA is expected to kick in by late in the day Sunday and
persist into Monday. Warm air is forecast to stick around Monday
night into Tuesday before the next system's strong cold frontal
passage knocks temperatures back down to near to below normal for
the middle of next week.
The probabilities of seeing a 0.10in or more of water equivalent in
any given 24 hour period in the out periods is low (less than 10
percent). Likewise, the chances of seeing 0.01in or more of freezing
rain/ice accumulation or 3 inches or more of snow are low. That
being said, the clipper system moving through North Dakota into
Minnesota Tuesday/Wednesday will need to be watched closely for any
shifts further south in track/placement, as this system holds the
chance of producing headline-able conditions. But for now, model
output/ensembles are still maintaining that the bulk of this system
will track through the region north of this CWA.
Looking a little bit more closely at the wind potential
Tuesday/Wednesday, it appears that a corridor of fairly strong winds
(off the surface) will be overspreading the CWA while it's within
the warm sector of the clipper system. Current model progs suggest
that it's not until at or after 21Z Tuesday that strong winds aloft
will be able to be mixed down to the ground, as that is roughly what
time the system's cold frontal passage is slated to begin sweeping
through the CWA, first across north central South Dakota, but then
quickly following through central and northeast South Dakota and
west central Minnesota, especially at or after 00Z Wednesday when
strong low level CAA, pressure rises and winds just a half kilometer
off the ground will be working in tandem to present a strong wind
concern. Not too confident about a blowing snow concern, though, if
the CWA has been at or above the freezing mark for nearly 48 hours.
Thinking there may not be much blowable snow left after warm
boundary layer conditions like that.
&&
.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1115 AM CST Fri Dec 5 2025
Terminals KABR,KATY,KPIR,KMBG
IFR/MVFR cigs will prevail through the next 24 hours. Any
lingering precip should taper off in the next hour. However,
another round of snow will develop early Sat morning.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory from 9 AM to 6 PM CST Saturday for
SDZ018-019-022-023.
MN...None.
&&
$$
DISCUSSION...20
AVIATION...20
