South Sioux City, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

829
FXUS63 KFSD 141127
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
527 AM CST Sat Feb 14 2026

.KEY MESSAGES...

- Near-record to record temperatures continue into the middle
  of next week. Average departures from normal will run +25 to
  +35 degrees.

- Fire weather concerns grow by Sunday and Monday as breezy
  southerly winds develop. Most areas at "high" grassland fire
  danger index levels, with locally "very high" conditions
  possible. A Fire Weather Watch has been issued for Gregory
  County SD Sunday afternoon.

- Outside of a few sprinkles and/or flurries near south of I-90
  today, dry weather expected until at least late Tuesday into
  Wednesday.

- Rain/snow chances (greater than 50%) remain focused north of
  I-90 into Wednesday, while a secondary system brings broad
  20-40% risks for light snow Thursday into Friday.

&&

.UPDATE...
Issued at 235 AM CST Sat Feb 14 2026

Tumbling temperatures last evening have leveled off as mid to
high level clouds increase across the area. Have maintained the
potential for isolated sprinkles/flurries this morning, but will
continue to evaluate as latest forecast soundings still depict a
deep dry sub-cloud layer.

Sunday looks a little more mixy with efficient south-southwest
low level flow, and given our ability to overachieve with even
lighter winds, have nudged the NBM toward slightly warmer and
especially drier/breezier guidance by mixing in some HRRR/RAP,
which have a tendency to excel in these patterns. This does
bring relative humidity/wind gusts close to critical levels
across our far southwest CWA, so issued a Fire Weather Watch for
Gregory County from Noon-6 PM CST Sunday. Wind gusts are more
uncertain farther to the northeast, but will monitor trends in
the models to see if this watch needs to be expanded with later
forecasts.

No significant changes to the mid-late week precipitation
chances. Seeing a slight northward trend for the first system
in the 13/00Z ensembles, though still moderate (50-70%) chances
for rain and/or snow across at least the northern half of our
forecast area Tuesday night-early Wednesday. Enough spread in
the timing/track of the late week wave that we still carry a
broad 20-40% chance for mainly light snow Thursday-Friday.

&&

.DISCUSSION...
Issued at 1200 PM CST Fri Feb 13 2026

THIS Afternoon: After temperatures fell into the teens thanks to
strong radiational cooling this morning, we`ve rebounded nicely this
afternoon into the 50s again.  More amazingly is the degree of
warmth we`re seeing despite nearly light to variable winds. While
925-850 mb temperatures are near the 90th percentile of climatology,
we`re seeing a strong surface response from dry and snow-less ground
cover.  In many locations, we`re also now thawing the first layers
of top-soil with a thaw down past 4" in quite a few locations.

TONIGHT: We`re likely to see a very warm night tonight as southerly
winds stay mixy in response to surface warm frontal development in
the Tri-State area. Short term models are showing a narrow channel
of 850:700 mb warm advection focused along I-90 overnight, which may
serve to increase mid-lvl clouds.

SATURDAY: A subtle mid-lvl wave passing along I-90 early Saturday
morning could bring just enough lift to produce virga or even a few
pockets of sprinkles to light rain into mid-morning.  Soundings show
the base of this activity near 5-6K ft AGL, but also maintain a very
dry layer below the cloud deck.  Once this wave passes, we should
again see another very warm day in the afternoon with highs in the
50s to 60s. Have blended a bit more HRRR/RAP into the NBM for highs
which will see more of the area into the 60s.

SUNDAY: Another very warm day is likely Sunday with temperatures
potentially rising another 1-3 degrees over Saturday.  Southwesterly
surface flow increases through the day as lee-side troughing
deepens.  The arrival of 925:850 mb winds approaching 30 to 40 knots
will promote both a strong warming signal but also a mix-down of dry
air signal.  NBM 25/75th Td spreads grow to 7-10 degrees in the
afternoon and evening, indicating the potential further mixdown of
dry air indicated by higher resolution guidance.  In coordination
with neighbors have nudged down afternoon dew points towards the
25th percentile. While not significant, the increase in afternoon
winds and lowering of dew points will lead to widespread "high" GFDI
values with pockets of "very high" GFDI values also possible.

MONDAY-TUESDAY: There still remains some disagreement with medium
range models on the track and southward progression of a frontal
boundary through the Tri-State area early Monday. The GFS/CMC both
stall this boundary, while the ECMWF push the boundary further
south.  This difference leads to a nearly 12 degrees spread in the
25/75th percentiles for high temperatures in the afternoon, with the
greatest spread north of I-90.  The GFS has shown signs of trending
closer to the EC, but so much is hinged on the amplitude and track
of upper troughing arriving from the west later on Tuesday.  For
now, will maintain the deterministic NBM, but temperatures should
still shift 5+ degrees either side of the current forecast.

PoPs have increased Tuesday into Tuesday night as the mid-lvl trough
approaches.   Strong divergence on the left exit of an approaching
jet should allow the trough to deepen slightly as it moves into the
Plains.  That said, there still remains intensity differences in the
upper wave with the CMC/GFS stronger and further southeast.
Regardless of solution, precipitation chances increase on the warm
advection wing Tuesday afternoon with probabilities for measurable
QPF now >60% in areas mostly north of I-90 and to the northeast into
west central Minnesota. Precipitation types remain strongly favored
towards rain.

WEDNESDAY-FRIDAY: The evolving mid-lvl flow pattern will continue to
lead to a slightly more interesting weather setup for the middle and
end of next week. After the departure of the Tuesday/Wednesday
system temperatures may cool slightly, but still remain above
normal. With a long wave trough across the western half of the CONUS
this will leave the region more susceptible to additional trough
ejection and deepening further east. One such wave to watch will be
arriving in the Plains around Thursday and Friday.  From an ensemble
perspective, ECE/GEFS/CMC and various AI based solutions remain all
over the board, resulting in low probabilities of measurable
precipitation over a very large area. While confidence in
temperatures hovering near the seasonal normals remains slightly
higher, this could complicate the ptype of any system that
approaches. Additionally, we`ll likely develop several days with
slightly stronger wind depending on trough deepening.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 527 AM CST Sat Feb 14 2026

VFR conditions and variable winds generally below 12kt will
prevail through this TAF period. Cloud bases around 10kft AGL or
below may produce very spotty sprinkles prior to sunset, but
impacts to aviation are not expected.

&&

.FIRE WEATHER...
Issued at 235 AM CST Sat Feb 14 2026

A very dry pattern, snow-free ground which has begun to thaw
through the upper few inches, and deep south-southwest flow
will promote efficient mixing on Sunday. This should yield a
very warm day with temperatures/dew points/gusts favoring the
warmer/drier/breezier side of ensemble guidance.

This should lead to elevated to near critical fire weather
conditions, especially toward south-central South Dakota where
slightly stronger southwest winds are favored. With a potential
for afternoon relative humidity as low as 20 percent, along with
southwest winds gusting near to above 25 MPH, have issued a
Fire Weather Watch for Gregory County SD from Noon-6 PM CST
Sunday.

Elsewhere across the forecast area, wind gusts and RH reaching
critical levels is more uncertain, though values do look close
as far east as I-29. Will continue to monitor the forecast
trends for possible expansion of the watch.

&&

.CLIMATE...
Issued at 1200 PM CST Fri Feb 13 2026

The forecast over the next 4 to 5 days will feature near record
to record highs and near record warm low temperatures:

Record high temperatures:

February 14: KFSD: 66/1954 KSUX: 62/1934 KHON: 60/1999 KMHE: 65/1954
February 15: KFSD: 63/1921 KSUX: 67/1921 KHON: 66/1921 KMHE: 66/1921
February 16: KFSD: 64/1981 KSUX: 66/1981 KHON: 62/2017 KMHE: 63/2017

Record warm low temperatures:

February 14: KFSD: 35/2002 KSUX: 37/2002 KHON: 32/2002
February 16: KFSD: 35/1998 KSUX: 37/1998 KHON: 36/2011
February 17: KFSD: 33/1992 KSUX: 37/1930 KHON: 35/1981
February 18: KFSD: 38/1994 KSUX: 39/1971 KHON: 35/1994

Additionally climate perspectives indicate that the current forecast
through Monday the 16th would push the mean monthly temperature
departure at Sioux Falls (+15 degrees), Sioux City (+15 degrees),
and Huron (+18 degrees) as the warmest February on record through
that date.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Fire Weather Watch Sunday afternoon for SDZ050.
MN...None.
IA...None.
NE...None.

&&

$$

UPDATE...JH
DISCUSSION...Dux
AVIATION...JH
FIRE WEATHER...JH
CLIMATE...Dux