468
FXUS63 KFSD 281846
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
146 PM CDT Sun Sep 28 2025

.KEY MESSAGES...

- Well above normal temperatures will continue through the
  upcoming week and into next weekend. A record or two may fall
  Monday and potentially Thursday/Friday.

- Dry conditions are also expected to continue through most of
  the week ahead. A few daybreak sprinkles/showers could be
  possible through the first half of the week, but chances
  remain >20%.

- Dry and occasionally breezy afternoon conditions over the next
  6 or 7 days could lead to low end fire weather concerns as
  fire fuels continue to dry out.

- Next reasonable risk for widespread rain arrives at some
  point next weekend, with a cooldown in temperatures to finish
  the weekend.

&&

.DISCUSSION...
Issued at 144 PM CDT Sun Sep 28 2025

THIS AFTERNOON: Another warm, dry, and breezy afternoon continues as
temperatures continue to rise into the 80s.  Southerly winds are
beginning to pull in slightly higher moisture into the region, with
the best moisture convergence into central South Dakota. With RH
values falling into the 20s, a slight increase in fire danger has
developed.

TONIGHT:  Winds weaken through the region, with upper cirrus
increasing through the night.  With southwesterly increases in the
LLJ developing after midnight, would not rule out high based ACCAS
field after 4am in central South Dakota.  Fairly dry sub-cloud layer
should limit any development to sprinkles.  Further east,
temperatures will be warmer than on Sunday morning, but still fall
into the 50s.

MONDAY: Concerns remain fairly minimal through the middle of the
week despite a broad increase in southwesterly low and mid-lvl flow
throughout the Plains.  The passage of a warm front Monday, along
with pocket of very warm low-lvl air will push highs near the 90
degree mark.  The recent dry spell may allow for sharper low-lvl
lapse rates and push high temperatures even higher in a few areas.
While most will fall just short of record highs, the record high at
Sioux Falls (FSD) is 90 degrees (set in 1897). This could certainly
be reached.  Afternoon wind gusts may break the 25 mph mark west of
the James River where low fire danger may develop in the afternoon.

TUESDAY-THURSDAY: Low-lvl warm pocket moves north of the area by
Tuesday which will cool highs slightly.  The southernly low-lvl flow
will push dew points into the 50s each day leaving minimum RH values
only on the lower to middle 30% range.  Winds at this point do not
signal any higher level widespread fire danger risk given remaining
greenness of fine fuels, but very localized pockets of low-moderate
risk especially west of the James River.   One thing of note that
with the nocturnal LLJ increase each night, isolated showers could
develop each morning, but placement and probability continues to
remain to low to indicate ATTM.

FRIDAY-SUNDAY: A frontal boundary stretches through the Dakotas by
the end of the week and beginning of the weekend. A narrow thermal
ridge builds over the CWA by Friday with deeper mixing allowing
highs to climb back near the 90 degree mark.  Once again, the Sioux
Falls record of 89 degrees (set in 1897) could be in jeopardy.
Precipitation chances finally return to a more widespread area for
next weekend as this aforementioned front slides into the Tri-State
area late Saturday and Sunday.  Ensemble probabilities of 0.10" rise
to around 30-40%, but coverage of rain and overall quantity of
rain remains very much in doubt.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1126 AM CDT Sun Sep 28 2025

VFR conditions continue into Monday morning. Occasional gusts to
20+ mph will subside this evening, with high based ACCAS cloud
field lifting through central South Dakota after 3am.

Winds will gradually increase from the south Monday morning as a
bit more mid-high level clouds remain in the region.

&&

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

&&

$$

DISCUSSION...Dux
AVIATION...Dux