576
FXUS63 KFSD 272128
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
328 PM CST Thu Nov 27 2025

.KEY MESSAGES...

- The rest of Thanksgiving Day will be dry and chilly with highs
  remaining largely below freezing.

- Snow remains on track to begin pushing into the area Friday
  morning and persisting through Saturday. A Winter Weather
  Advisory has been issued for most locations along and west of
  I-29. A Winter Storm Warning has been issued for most
  locations east of the interstate. Generally 3-6 inches is
  expected in the Advisory and 6 to 10 inches in the Warning.

- This system will cause disruptions to post-Thanksgiving Day
  travel, so be sure to keep up to date with the latest
  forecast and be prepared to adjust your travel plans.

- Much colder temperatures are expected for the bulk of next
  week with the potential for lows down to the single digits
  and wind chills below 0F.

&&

.DISCUSSION...
Issued at 327 PM CST Thu Nov 27 2025

Low level stratus continue to blanket part of the area this
afternoon. The stratus is expected to continue to sink southwards
which could bring a return of sunshine to locations along and north
of highway-14, especially along its southwest Minnesota portion. The
stratus has kept high temperatures cool though, only up to the 20s
with a few locations along highway-20 cracking 30F. Clouds will
increase in coverage aloft tonight as the wave responsible for the
upcoming snow pushes into the pacific northwest. At the surface,
winds will turn out of the southeast by Friday morning. Despite the
southerly component to the wind and cloud cover, low temperatures
will fall to the teens overnight.

Snow begins to fall across parts of central and south central South
Dakota just before daybreak on Friday. This initial snow will be
driven by a developing low level jet (LLJ) which will strengthen
warm air advection (WAA) aloft. This will also tighten the thermal
gradient, leading to an elevated frontogenetic (FGEN) zone. Some
instability looks to reside just above the front, signaling that
this band will be a more narrow and a slightly stronger band. Could
see a small delay in snow reaching the surface due to top down
saturation but don`t think that it will last long given the forcing
in place. The band of snow will push eastwards throughout the
morning hours. The band will be strongest in the morning as omega
(upward motion) will be strongest though latest guidance is
persistent in keeping the maximum value of omega just below the
dendritic growth zone (DGZ). That said, there will still be some
overlap to promote sufficient snow growth. As the band slides
eastwards, it will expand in coverage during the afternoon hours on
Friday. Latest guidance shows that saturation in the DGZ will be
lost along and around highway-20 Friday afternoon and evening. This
will result in a change over from snow to light freezing drizzle.
This freezing drizzle looks to be quite light though with amounts on
the order of a light glaze expected. Southeasterly winds will pick
up during the day as well but the strongest winds with gusts up to
about 30 mph mainly across central and south central South Dakota.
The winds could result in some blowing snow though there may be a
bit of an offset between the strongest winds and falling snow as the
bulk of the snow looks to be east there by Friday afternoon. The
previously mentioned WAA looks to weaken Friday night as the LLJ
weakens as the base of the mid level wave pushes into the forecast
area. Snow will transition to a light to perhaps moderate rate at
this time. Some of the convective allowing models (CAMs) show dry
air working into locations west of I-29, potentially shutting off
snow for a bit. Have kept PoPs in place given that low level thermal
profiles remain saturated through the night which can continue light
snowfall. The bulk of the accumulating snow during this period of
time will fall east of I-29.

Snow persists through the day on Saturday though at a lighter rate.
The main upper level trough will finally swing through the area,
resulting in slightly better forcing come the morning hours on
Saturday. This will cool thermal profiles enough to resaturate
profiles west of I-29, increasing snowfall rates a bit. The base of
this wave will push through the area during the afternoon hours on
Saturday. This will slowly decrease snow from west/northwest to
east/southeast through Saturday afternoon and evening. Snow will
finally be east of the area come Saturday night. In terms of totals,
the forecast remains generally on track with locations east of I-29
getting between 6 to 10 inches of snow, highest along and east of
highway-60. Lighter amounts between 3 and 6 inches is expected along
and west of I-29. As such, have issued a Winter Weather Advisory for
locations along and west of I-29, including Lincoln and Lyon
counties in southwest Minnesota. A Winter Storm Warning has been
issued For the majority of locations east of I-29.

Sunday will be the first dry day with the upper level trough well
east of the area. This will be the first of a stretch of below
average temperature days with highs only warming to the teens. Highs
look to warm a bit more to the 20s for the majority of next week
with lows falling to the teens and single digits. Although next week
does not look all that breezy, any wind will result in cold wind
chills with values dropping below 0F at times. With broad northwest
flow aloft, dry conditions look to prevail for Sunday through the
middle of next week at this time.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1135 AM CST Thu Nov 27 2025

Latest satellite shows a broad stretch of MVFR/IFR stratus across
the area late this morning along and north of highway-18. This batch
of stratus will continue to sink southwards through the afternoon
and into the evening hours. Ceilings will return to VFR levels in
its wake. Light northwest winds will persist through the rest of
today before turning out of the southeast tomorrow morning. Snow
will be beginning to fall across south central South Dakota tomorrow
morning within a band. This band will push eastwards through the
rest of the morning hours and should reach KHON and KSUX by the end
of the TAF period. Ceilings look to remain mostly VFR though could
drop to MVFR thresholds depending on low level humidity.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Winter Storm Warning from noon Friday to midnight CST Saturday
     night for SDZ071.
     Winter Weather Advisory from noon Friday to midnight CST
     Saturday night for SDZ040-055-056-062-067.
     Winter Weather Advisory from 9 AM Friday to noon CST Saturday
     for SDZ038-039-053-054-059>061-065-066-069-070.
     Winter Weather Advisory from 6 AM Friday to noon CST Saturday
     for SDZ052-057-058-063-064-068.
MN...Winter Storm Warning from noon Friday to midnight CST Saturday
     night for MNZ080-081-089-090-097-098.
     Winter Weather Advisory from noon Friday to midnight CST
     Saturday night for MNZ071-072.
IA...Winter Storm Warning from noon Friday to midnight CST Saturday
     night for IAZ001>003-012>014-020>022-031-032.
NE...Winter Storm Warning from noon Friday to midnight CST Saturday
     night for NEZ014.
     Winter Weather Advisory from 9 AM Friday to noon CST Saturday
     for NEZ013.

&&

$$

DISCUSSION...Meyers
AVIATION...Meyers