Yankton, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

158
FXUS63 KFSD 070347
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
947 PM CST Fri Mar 6 2026

.KEY MESSAGES...

- Thunderstorms will diminish very early Saturday morning.

- A wintry mix will continue along and east of I-29 into early
  Saturday, as a secondary band of light snow also arrives from
  the West. Additional amounts will be less than 1" and a glaze
  of ice.

- Expect icy roads throughout the region Saturday morning due to
  freezing of standing water on roads.

- Above normal temperatures will dominate the week ahead with
  occasional low precipitation chances.

&&

.UPDATE...
Issued at 940 PM CST Fri Mar 6 2026

Scattered convection continues to wane as instability drifts off
the east. Lingering convection may still produce very small
hail, but moreso light icing as surface temperatures are falling
near freezing.

Further northwest, we continue to see persistent freezing
drizzle which transitions towards a snow/sleet/freezing rain mix
as you approach stronger 700 mb frontogenesis. Most icing has
been on elevated surfaces, however as temperatures fall into the
middle 20s, the pavement and other surfaces are also now icing.
Into central South Dakota, snow has prevailed for the past 2
hours, with minor accumulations of a dusting to 2-3" by time the
snow ends after midnight in areas from Huron down to
Chamberlain.

For the rest of tonight, we`ll continue to see the western edge of
precipitation slide eastward bringing a wintry mix which will change
to snow. This eastward motion should increase over the next 2-4
hours as vorticity in western Kansas and Nebraska increases it`s
forward speed. A faster eastward progression will also lower
additional snow totals to a dusting to half inch in most areas.
Precipitation will end by daybreak, which may allow the advisory
to be ended early. HOWEVER, expect to wake up to a considerable
amount of slick spots through the region Saturday.

No changes made to the Saturday forecast as winds turn westerly
and skies gradually clear through the day. Low-lvl warm
advection will spread a large area of warm air aloft through the
Plains with favorable westerly surface winds pushing highs into
the 50s and even 60s. Any icing or snow that falls tonight
should be a distant memory by the afternoon.

A peak at Sunday reveals an even warmer day as westerly winds
and strong warm advection surge high temperatures well into the
60s and even 70s. Depending on how quickly surface fuels dry out
after a damp day, fire danger may elevate slightly.

&&

.DISCUSSION...
Issued at 1246 PM CST Fri Mar 6 2026

Model soundings continue to hang on to the warm layer aloft, leading
to mainly liquid precipitation in most locations through late
afternoon into early evening. The exception will be near and west of
the James Valley where the warm layer aloft is cold enough that
mainly snow is expected. For the majority of the afternoon most
locations will see mainly drizzle with a deep saturated layer in the
low levels and the higher dgz too dry to support precipitation
production. By late afternoon the main wave will lift northeast and
bring in slightly higher lapse rates which allows for some weak
instability at the top of the moist layer and should allow for bands
of precipitation to develop. With the warm layer aloft in place and
near to below freezing temperatures at the surface freezing rain
will be the main precipitation type, although some sleet will be
possible as colder air starts to settle in mid to late evening. By
late evening as the wave is shifting east, the warm layer cools and
most precipitation should gradually transition from mixed to snow.

Away from the wintry precipitation, spotty showers and thunderstorms
will be possible in mainly northwest IA this afternoon into the
evening and could produce very isolated small hail and wind gusts to
50 mph. The challenge to produce any severe weather will be a fairly
elevated freezing level, about 9000 kft, and CAPE values only
running about 300-500 J/kg.

Much drier air pours in later tonight into Saturday morning which
will bring an end to the precipitation potential. A fast moving
ridge of high pressure will move through Saturday, which will bring
southwest flow to the area through the afternoon. This should allow
for mild temperatures with some 50s west of I-29 and 40s near and
east of I-29.

Westerly flow remains in place Saturday night into Sunday night,
which will lead to some very mild conditions. Highs on Sunday should
be well into the 60s in most locations, with a few 70s possible.

Faster westerly flow aloft remains in place through the week, which
should lead to some ups and downs in temperatures with mainly dry
conditions. There will be some minor chances for precipitation with
Monday night into Tuesday the better chance. Overall highs will
generally be from about 45 to 55 Monday through Friday, with Thursday
seeing the best chance to get back into the 60s.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 505 PM CST Fri Mar 6 2026

MVFR to IFR conditions continue through the area as expansive
drizzle, freezing drizzle, sleet, and even snow have developed.
Very isolated lightning strikes may continue to the I-29
corridor through mid-late evening. The aforementioned
precipitation, concentrated mostly west of I-29 currently, will
continue to move east into the overnight hours. Further
southeast, showers and a few thunderstorms may develop over
northwest Iowa with light fog persisting.

Have delayed ending of precipitation slightly after midnight
with snow moving out of the area by 6am. MVFR ceilings will take
a big longer to erode, but should clear most areas by mid-day.

One concern for aviation partners tonight will be potential for
flash freezing as temperatures fall. Northwest winds gusting to
25 mph may help dry pavement somewhat, but still anticipating
icing to develop.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory until 9 AM CST Saturday for SDZ040-055-
     056-060>062-065>071.
     Winter Weather Advisory until 3 AM CST Saturday for SDZ038-039-
     050-052>054-057>059-063-064.
MN...Winter Weather Advisory until 9 AM CST Saturday for MNZ071-072-
     080-081-089-090-097-098.
IA...Winter Weather Advisory until 9 AM CST Saturday for IAZ001>003-
     012>014.
NE...None.

&&

$$

UPDATE...Dux
DISCUSSION...08
AVIATION...Dux