287
FXUS63 KFSD 150538
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
1238 AM CDT Mon Jun 15 2026

.KEY MESSAGES...

- Near to below normal temperatures will continue well into
  next week with highs mainly in the 70s to 80s expected.

- Scattered showers will return to the area by Monday afternoon.
  While severe weather is not expected, an occasional stroke of
  lightning and strong wind gusts up to 40-50 mph will be
  possible.

- More concrete shower and thunderstorm chances (50%-80%) will
  return Tuesday night into Wednesday. At this time severe
  weather is not anticipated but once again gusty winds to 50
  mph with these showers and isolated storms will be possible.

&&

.UPDATE...
Issued at 839 PM CDT Sun Jun 14 2026

Light and variable winds overnight along with clear skies will allow
for effective radiational cooling. As such overnight lows are
projected to fall into the upper 40s to low 50s. West winds will
begin to increase shortly after sunrise Monday as a mid-level
wave moving in from the northwest compresses the SPG. Afternoon
gusts of 20-30 mph are expected for areas west of I-29. Slightly
lower gusts of 15-25 mph to the east. Breezy winds continue
into the early part of the evening.

Monday late afternoon the aforementioned wave and surface cold front
begin to work into the central South Dakota region, turning winds to
the northwest. As it does so chances for scattered rain showers and
isolated thunderstorms increase (30-35% probability) in the late
afternoon to overnight hours. The area most likely to see
storms is northeast of a rough line from Chamberlain to Sioux
City. Though a few isolated sprinkles are possible to the
southwest. Severe weather is not anticipated, but there is
enough instability for several lightning strikes. Strong wind
gusts of 40-50 mph are also possible thanks to a deep, very dry
inverted V sounding. Moisture is a bit scant with only a shallow
layer between 700-600 mb. Coupled with the deep dry layer it is
likely that accumulation totals will be low, a trace to a
couple hundredths. Showers may linger into early Tuesday morning
over southwest Minnesota. The rest of Tuesday looks to be dry
with decreasing clouds. Highs will climb into the 70s and 80s.

Tuesday night into Wednesday brings the next chances for more
widespread showers and thunderstorms. Please see the Discussion
below for further details.

&&

.DISCUSSION...
Issued at 1246 PM CDT Sun Jun 14 2026

Northwest winds will diminish this evening with light winds expected
through the night. This should allow for solid radiational cooling,
with Monday morning temperatures bottoming out in the 40s in most
spots.

A quick moving system will move through the area on Monday which
will bring about gusty winds again, with a few gusts around 30 mph
possible. Model soundings continue to indicate weak surface based
instability, mainly late afternoon into the evening. This will bring
about the threat for a few showers, possibly an isolated
thunderstorm. While severe weather is not expected, a nice inverted
v sounding suggests some stronger winds gusts, likely 40 to 50 mph.
The better chances for these gusty winds should be near and
northeast of a Huron to Spencer IA line.

The models continue to bring through the next system of interest
Tuesday night into Wednesday. Warm advection increases Tuesday night
ahead of the wave with mid level lapse rates increasing to about 7.5
degrees C. This may lead to some elevated showers or a very isolated
thunderstorm. Weak instability still appears to be a limiting factor
for development. By Wednesday afternoon this system is blowing by
and severe chances appear to be pretty low. However, similar to
Monday some weak surface based instability with a dry sub cloud
layer and a strong westerly unidirectional wind could lead to gusty
winds with any afternoon or evening shower that could develop,
possibly gusts of 50 to 55 mph.

Thursday and Friday look generally dry and pleasant with highs
Thursday into the 70s and Friday mostly in the 80s.

The chance for showers and thunderstorms returns for the weekend but
for now confidence is low to moderate on location and timing. Some
hints that the better chances may reside across Nebraska. Otherwise
temperatures remain seasonally mild.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1238 AM CDT Mon Jun 15 2026

VFR conditions are expected for the period. Winds are light and
variable, becoming west after sunrise and increasing into the
afternoon. Gusts of 20-28 kts are expected for areas along and west
of I-29 and into southwest Minnesota. Northwest Iowa will see
slightly lighter gusts at 15-20 kts. Winds decrease through the
evening, remaining slightly breezy at 15 kts or so through the end
of the period.

Clear skies will become scattered to broken early Monday morning as
a mid-level wave and associated surface front move in from the
northwest. With it come chances for evening scattered showers and
isolated thunderstorms. Severe weather is not anticipated, however a
very dry subcloud layer could result in strong wind gusts of 40-50
kts under any stronger storms. The main storm activity should remain
along and north of I-90, but some guidance hints at a few showers as
far south as the SD/NE border and into northwest Iowa. Showers
should be pushing east of the region around the end of the
period.

&&

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

&&

$$

UPDATE...AJP
DISCUSSION...08
AVIATION...AJP