Sioux City, Iowa 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

598
FXUS63 KFSD 041828
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
128 PM CDT Mon May 4 2026

.KEY MESSAGES...

- A few sprinkles to light showers will continue through this
  evening especially across the Highway-20 corridor with mainly
  light accumulations expected.

- Patchy areas of frost will be possible tonight mainly across
  the Highway-14 corridor. Additional chances for scattered
  areas of frost/freeze conditions are expected by midweek.
  However, some uncertainty remains. Make sure to cover/bring in
  any sensitive vegetation!

- After below normal temperatures through midweek, near to
  above normal temperatures will continue into the weekend with
  highs mainly in the 60s to 70s.

&&

.DISCUSSION...
Issued at 126 PM CDT Mon May 4 2026

CURRENTS & TONIGHT: Another mild and breezy day persists! Taking a
look across the area, the breeziness continues behind this morning`s
cold front with most observations showing northerly wind with gusts
between 25-35 mph along with temperatures mainly in the 50s to 60s.
With deeper mixing and lower dew points, near-critical RH values
continue with values in the 25-30 percent range. While the
combination of the ingredients above have led to locally elevated
fire concerns; decided to hold off on any fire-related headlines
mainly due to greening fuels. Otherwise, can`t completely rule out a
few scattered sprinkles along and south of the Highway-20 corridor
this evening. Nonetheless, with limited saturation according to
sounding; expect any accumulations to very light at best. Lastly, as
cloud cover thins and surface winds lighten overnight; an influx of
cooler air will lead to temperatures mainly in the low to upper 30s
for the night. With this in mind, could see some patchy frost
develop mainly along the Highway-14 corridor overnight. While the
extent is still in question mainly due to a higher dew point
depression, decided to also hold off on an frost/freeze headlines at
this time.

TUESDAY-THURSDAY: Looking into the midweek, we`ll continue to sit in
northerly flow aloft as a predominantly troughy pattern continues
aloft. With lingering mid-level cold air advection (CAA) and
predominantly northwesterly flow in place at the surface, expect
temperatures to temporarily decrease through at least Wednesday with
highs mainly in the low to upper 50s. With lows expected to be near
to below freezing (26-32 degrees) each night, additional chances for
more widespread frost/freeze development are expected especially by
Wednesday. However, with an 8-10 degree dew point depression and
variable cloud cover at times; there are still some questions as to
extent of the frost/freeze. Nonetheless, we should be about to hit a
turning point by Thursday as increasing mid-level warm air advection
(WAA) and the return of southwesterly to westerly winds help highs
climb back into the 60s. Lastly, any precipitation chances continue
to look rather limited for the period.

THE WEEKEND: Heading into the extended period, an active pattern
will once again return as northwesterly flow helps usher in multiple
waves through our area. The strongest of which looks to arrive
between Saturday to Sunday. While there is still some variability
among long-range guidance, this still looks like our best chances
(30%-40%) for areas along and south of I-90 to see rain. This is
further agreed upon within ensemble guidance with most members
showing a 20%-40% chance of 0.10" of an inch or greater of QPF.
While not a drought buster by any means, any potential rain chances
are encouraged at this point. Lastly, we`ll continue our warming
trend into the weekend with highs mainly in the 60s to low 70s.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1222 PM CDT Mon May 4 2026

VFR conditions will persist this TAF period. Besides some
approaching VFR stratus and a few sprinkles to light showers at
KSUX this evening, not expecting much avaition-wise. Otherwise,
northerly surface winds will continue to be breezy through this
evening with gusts between 25-35 mph. Lastly, winds will
gradually decrease after sunset.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.

&&

$$

DISCUSSION...05
AVIATION...05