741
FXUS63 KFSD 302311
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
611 PM CDT Mon Jun 30 2025

.KEY MESSAGES...

- Chances for isolated to scattered (30 to 50%) showers and
  storms return Wednesday and Thursday. Shower and storm
  chances continue for Independence Day and through the holiday
  weekend. Currently, highest chances (40-70%) are on Friday the
  4th and Saturday. Severe weather chances are low (<20%) at
  this time. Keep an eye on the forecast if you have outdoor or
  travel plans.

- Temperatures generally near to above normal through the next
  week. Thursday through Friday could see heat index values
  approach 100 degrees.

&&

.DISCUSSION...
Issued at 308 PM CDT Mon Jun 30 2025

Mainly quiet conditions persist this afternoon as high pressure is
pushing through the Northern Plains. With the base of an upper level
wave sitting over the forecast area, light showers remain possible
across portions of southwest Minnesota for the rest of the afternoon
hours. A stay lightning strike is possible with the showers. These
showers will wane come the evening hours, leaving quiet conditions
for the overnight hours. Low temperatures will fall to the upper 50s
to low 60s.

Tuesday will be a quiet day as surface high pressure pushes
southeast of the Northern Plains. This will set up southerly return
flow on the backside of the departing high. The southerly flow will
help push highs back to the 80s and low 90s across the area. While
the daylight hours will be dry, a weak wave will push into the area
Tuesday night. Minor instability will be in place so a few rumbles of
thunder are possible with the showers that pass through the area.
Low temperatures will be a bit warm, only falling to the 60s
overnight.

Upper level ridging will slowly push into the central US through the
Wednesday and Thursday. This looks to bring renewed chances for
showers and storms to the Northern Plains with the highest chance
for rain coming in Wednesday. The ensembles support this as they all
show modest probabilities between 30-50% for exceeding a tenth of an
inch of rain. With the ridge overhead, high temperatures will be
warming to the 80s and 90s, warmest on Thursday. Heat indices will
also be in the 80s and 90, again warmest on Thursday. A few
locations could see heat indices approach 100F on Thursday as well.

The upper level ridge axis will push east of the area on Friday,
resulting in height falls aloft. Medium range guidance also shows a
shortwave trough pushing into the Plains but varies in the
structure of this wave. Warm air advection (WAA) will be
strengthening ahead of this incoming wave. With southerly flow in
place at the surface, another day with high temperatures in the
upper 80s and 90s is likely. Heat indices will again warm to the 90s
to potentially nearing 100F. With broad synoptic lift in place via
WAA and differential positive vorticity advection (DPVA), showers
and storms are possible. The atmosphere will be generally uncapped
which should result in scattered showers and storms through the
afternoon and evening hours. As of now, the highest probabilities
for rain will come Friday evening as the base of the wave pushes
into the forecast area. The ensembles support this as they show a 40-
70% chance for rainfall amounts to exceed a tenth of an inch. Thus,
think that the evening of Independence day could be quite stormy. At
the same time, wind shear looks quite weak so the severe storm
potential is low (<20% chance).

Chances for showers and storms look to persist through Saturday
though medium range guidance shows increasing variance in the waves
evolution along with machine learning guidance. The ensembles on the
other hand show the wave flattening. The ensembles also show
decreasing rain chances, down to a 20-40% chance for exceeding a
tenth. That said, showers and storms look to stick around but with
decreasing coverage. High temperatures will cool back to near
seasonable in the 80s to up to around 90F.

Highs look to remain near seasonable in the 80s and 90s for Sunday
and Monday along with a continuation of rain chances. However, tough
to say how high the rain chances could be with medium range guidance
showing increasing variance in the upper level pattern. Thus, have
left model blended PoPs in place but will continue to monitor
trends.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 610 PM CDT Mon Jun 30 2025

Gusty northwest winds will quickly diminish through sunset and
remain fairly light through tomorrow. VFR conditions are
expected.

&&

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

&&

$$

DISCUSSION...Meyers
AVIATION...08