177
FXUS63 KFSD 070824
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
324 AM CDT Tue Oct 7 2025

.KEY MESSAGES...

- Dry conditions and mostly quiet weather is expected through
  the work week.

- Today will be the last day this week with seasonable
  temperatures before temperatures warm to above average for
  the rest of the week.

- The next chance for rain will not arrive until the weekend. As
  of now, there is only a 30-50% chance for rainfall amounts to
  exceed a tenth of an inch.

&&

.DISCUSSION...
Issued at 323 AM CDT Tue Oct 7 2025

Quiet conditions begin the day early this morning. Mid level clouds
are pushing southwards through northern and northeastern South
Dakota and could result in a sprinkle along and north of highway-14.
This mid level cloud deck will dissipate into the early afternoon
hours, leaving mainly sunny skies for the rest of today. Surface
ridging will be sliding through the forecast area at the surface,
keeping winds light. Highs will warm to the 60s across the area,
making for a solid Fall day. Overnight lows will fall to the upper
30s and 40s.

The previously mentioned surface ridging will slide east of the
Northern Plains on Wednesday, resulting in a tightening of the
surface pressure gradient. This will re-introduce breezy southerly
winds to the area. Gusts up to 20-40 mph is expected, strongest west
of I-29, especially towards south central South Dakota. High
temperatures will warm to the upper 60s and low 70s which will
result in lower humidity values. As of now, the lowest relative
humidity (RH) values look to occur east of I-29. This makes for a
separation of the strongest winds and lowest RH values. While
elevated fire danger is possible, fire danger looks to be capped at
high due to this difference. Any elevated fire danger will come to
an end during the evening hours as temperatures cool. Overnight lows
will fall to the upper 40s to 50s.

Heights build aloft for Thursday and Friday. With the Northern
Plains residing downstream of a building upper level ridge, dry
conditions are expected. This ridging will continue above average
temperatures with highs remaining in the 70s to even toughing 80F in
a few places. Marginally breezy winds are expected for Thursday
weakening for Friday. Some elevated fire danger is possible on
Thursday but this will be dependent on how low humidity levels get.

Things may begin to change heading into the weekend and into early
next week. Medium range guidance shows a longwave trough pushing
into the central CONUS through this period of time. The ensembles
also show this wave as well but are in better agreement in its
evolution than the deterministic models. What the ensembles, and
clusters as well, show is the upper level trough becomes
increasingly positively tilted as it pushes into the Northern
Plains. This evolution suggests that above average temperatures will
continue through the weekend with highs remaining in the 70s to
touching 80F. There could be chances for rain throughout the weekend
but deeper moisture looks to be difficult to come by as the euro
ensemble is the only ensemble that shows probabilities greater than
50% for exceeding a 55F dew point. That said, the NAEFS ensemble
does show precipitable water (PWAT) values up to the 90th percentile
of climatology being advected into the Northern Plains. The
ensembles show a broad 30-50% chance for exceeding a tenth of an
inch of rain, highest on Sunday. Will keep an eye on this rain
potential.

Broad upper level troughing looks to remain in place into next
Tuesday. While specific details are uncertain at this point in time,
temperatures look to cool to near seasonable levels since a cold
front will pass through the region over the weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1016 PM CDT Mon Oct 6 2025

VFR conditions expected through the period. Mid-level clouds will
move into the Highway-14 corridor early this morning, and these
could squeeze out light showers/sprinkles. Additional mid-level
clouds look to develop in the afternoon along the I-90 corridor,
with the same light shower/sprinkle potential. Not enough confidence
in areal coverage of these showers to include in the TAFs, but
visibility restrictions are not expected either way. Winds will be
mainly light and variable through the period.

&&

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

&&

$$

DISCUSSION...Meyers
AVIATION...Samet