090
FXUS63 KFSD 222315
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
615 PM CDT Wed Jul 22 2026

.KEY MESSAGES...

- Cloud cover and rain will keep temperatures below normal
  through Thursday, before beginning to warm to near seasonable
  on Friday.

- Chances (20-60%) for rain will persist through Friday.
  Locations along and south of a Chamberlain, South Dakota to
  Beresford, South Dakota to Storm Lake, Iowa line may rainfall
  amounts between a quarter to a half an inch. Lighter amounts
  are expected north of this line.

- Temperatures will warm back to above average this weekend and
  into early next week. High temperatures will rise into the 90s
  to potentially the low 100s. Make sure to drink plenty of
  water and take breaks from the sun if you will be outdoors
  this weekend.

&&

.DISCUSSION...
Issued at 142 PM CDT Wed Jul 22 2026

Light rain showers continue to drift through part of the area this
afternoon. The abundant cloud cover has keep high temperatures on
the cooler side with highs only warming to 60s and 70s. Rainfall
amounts up to a few hundredths to a tenth or so remain mainly across
south central South Dakota. Any chance for rain will come to an end
by this evening, leaving partly cloudy to cloudy skies for the
overnight hours. Despite the cloud cover, a surface high pushing
through the area will keep light east/southeast flow going through
the overnight timeframe, allowing for low temperatures to fall to
the 50s to low 60s across the area.

Cloudy skies will persist through the day tomorrow, keeping high
temperatures near to below average again in the 70s with a few spots
reaching into the low 80s. Southerly return flow will pick up as the
previously mentioned surface high departs to the southeast. Winds
will still remain on the lighter side but a few gusts up to 20-25
mph is expected. Another shortwave trough will push through the
forecast area, resulting in showers across the area once again.
These showers look to be more widespread though remaining along and
south of I-90 for the day. Forcing will be a bit stronger with this
chance for rain along with very minor instability being present at
or below 100 J/kg. This will bring overall higher rainfall amounts
to locations along and south of a Chamberlain, South Dakota to
Beresford, South Dakota to Storm Lake, Iowa where rainfall amounts
between a quarter to a half an inch are possible (20-60%). Lighter
amounts are expected north of this line. With the very minor
instability in play, an isolated rumble of thunder is possible. This
light rain will persist into the night before pushing southeast of
the area by Friday morning.

Upper level ridging will begin to build over the central Plains on
Friday, raising high temperatures back to the upper 70s, 80s, and
low 90s. This trend will continue through the weekend as the thermal
ridge slides eastwards. High temperatures look to return to above
average with highs in the 90s to low 100s. The ensembles support
this as they show high probabilities (60-100% chance) for high
temperatures to exceed 90F along and west of I-90 over the weekend.
Their probabilities drop to a 30-40% chance for highs to break 100F
over the same area. The EFI also supports this as it shows 60-100%
of its members suggesting anomalously warm temperatures this weekend
and a shift of tails exceeding 1. Thus, will have to continue to
monitor the potential for heat headlines being needed, especially as
dew points look to remain in the 60s and 70s.

The heat looks to begin to wane on Monday as high temperatures look
to only warm to the 90s. Highs will slightly cool into the middle of
next week. With the forecast area being just on the northern
gradient of the upper level ridge, ridge riding shortwaves could
bring rain and perhaps storm chances back to the area. The ensembles
only show low probabilities ranging from 0 to 30% so confidence is
low in this potential as of now. Machine learning guidance also only
shows a half a percent to about a 5% chance for severe storms Sunday
through the middle of next week. Something to keep an eye on as we
head into another hot and humid pattern.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 612 PM CDT Wed Jul 22 2026

VFR conditions are expected for the period. Winds will be light and
variable overnight. Patchy fog is possible overnight and early
Thursday morning for areas along water ways and low areas, mostly
east of I-29. Any fog should burn off shortly after sunrise.

By mid-morning winds will be southerly and breezy, gusting 15-25 kts
for areas along and west of I-29, with the highest gusts along
and west of the James River Valley. Areas to the east will see
gusts 15 kts or less. There is a low chance (<30%) for showers
and possibly weak thunderstorms Thursday afternoon into the
overnight for areas along the central to southern Missouri
River Valley. Currently storms do not look to impact KHON or
KFSD. Periodic storms are possible for KSUX after 24.18Z.

&&

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

&&

$$

DISCUSSION...Meyers
AVIATION...AJP