Sioux City, Iowa 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

645
FXUS63 KFSD 060328
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
1028 PM CDT Sat Jul 5 2025

.KEY MESSAGES...

- Additional showers/storms are possible Sunday (west of James
  River Valley) and Monday night-Tuesday. Some stronger storms
  are possible, but details are uncertain.

- Seasonal temperatures in the upper 70s and 80s are expected
  through the first half of the week, warming some by the middle
  of the week.

&&

.DISCUSSION...
Issued at 203 PM CDT Sat Jul 5 2025

Rest of Afternoon and Evening: Scattered showers and weaker
thunderstorms continue to drop south through the afternoon and early
evening hours. Poor mid level lapse rates and unsubstantial DCAPE
keep the severe threat very low but lightning will still be a concern
for those with outdoor activities. The other thing we`ve been
monitoring is a good overlap of surface vorticity and 0-3 km MLCAPE,
along with NST parameter values of 1-4 allowing for some
potential of a weak funnel cloud or landspout until closer to
the sunset hours. This atmospheric potential has been confirmed
with recent reports in southern Minnesota.

Tonight: Precip activity should quickly exit south of the Hwy 20
corridor by sunset with decreasing cloud cover, light winds,
and benign weather through the overnight.

Sunday: Expectation is still that a decaying MCS may try to approach
our western coverage area by daybreak Sunday although likely will
encounter difficulty making it much past the MO River with a
lack of instability. This may however keep some shower chances
in the forecast near/west of the James River along with
associated cloud cover. With a northerly wind ushering in lower
dewpoints, conditions will be more comfortable with temperatures
in the mid 70s to mid 80s.

Monday and Tuesday: Fairly robust wave moves through the zonal flow
along the International Border later Monday/Monday night. This will
likely be our next focus for thunderstorm chances with shear and
instability profiles supportive of at least some potential for
strong to severe thunderstorms, perhaps favoring the MO River Valley
where the sharper theta-e gradient currently looks to reside. SPC
currently delineates most of our coverage area in a level 1 out of 5
risk.

Wednesday through Friday: Models agree that ridging develops across
the Rockies and slides east by mid week. Agreement then fades
although it appears this ridging will quickly be interrupted by some
sort of wave late in the work week. Still time to refine the details
so just lower end chance level (30-40%) storm chances right now but
this will also be a period to monitor for additional severe weather
per ML and AI probabilities. Within the ridging, temperatures likely
warm back into the mid 80s to 90s, before retreating behind the
previously mentioned wave.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1027 PM CDT Sat Jul 5 2025

VFR conditions are expected to prevail for this period. A few light
rain showers linger in portions of northwestern Nebraska and
northwestern Iowa. These will continue to diminish and move out of
the area over the next couple of hours. Clouds will gradually
diminish after. Winds will become light and variable and remain so
for the majority of the period.

Mostly clear skies for areas east of the James River Valley. West of
the James clouds will build in again early Sunday morning as a weak
system skirts our western boarders. Currently, the only site at risk
for rain Sunday morning is KHON, but confidence is low in this
occurring.

&&

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

&&

$$

DISCUSSION...Kalin
AVIATION...AJP