152
FXUS63 KFSD 081946
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
246 PM CDT Sun Jun 8 2025

.KEY MESSAGES...

- Gusty west-northwest winds with occasional gusts up to 45 mph
  will continue through this evening. A Wind Advisory is in
  effect for the James River Valley into southeastern South
  Dakota through 7 pm.

- Isolated to scattered showers for parts of the area tonight.
  Only very light rainfall accumulation is expected.

- Wildfire smoke aloft will return to the area on Monday,
  possibly reaching the surface on Monday afternoon.

- Below normal temperatures to start the week, but warmer air
  builds in mid-late week. Highs mainly in the 80s from Tuesday
  onward, with some 90s possible (greatest chance south of I-90
  on Wednesday). Sporadic rain/thunderstorm chances return late
  this week, but low confidence in timing and location.

&&

.DISCUSSION...
Issued at 245 PM CDT Sun Jun 8 2025

A mild and windy day in progress across the area with current
temperatures primarily in the 70s. Winds have outperformed almost
all guidance today, consistently gusting around 35 to 45 mph. As a
result, a Wind Advisory is in effect trough the James River Valley
and southeastern SD through mid evening. That being said, model
soundings do indicate an overall downward trend in the strongest
wind gusts in the late afternoon. The wildfire smoke which reduced
surface visibilities earlier in the day has now pushed off to the
southeast, with current observations indicating visibilities of 8
miles or greater.

For tonight, an upper level closed low over northern MN shifts into
western WI by Monday morning - with the surface reflection cold
front sweeping across our area overnight. This will bring isolated
to scattered showers through the northeastern half of the CWA (east
central SD/southwestern MN/parts of northwest IA). Even so, any
precipitation amounts are expected to be light - only a couple
hundredths at best. Overnight lows will be seasonably cool, in the
upper 40s to lower 50s.

Any showers will exit the area by Monday morning as the upper level
low moves into the Great Lakes region. Unfortunately, latest
guidance suggests that smoke will return to the area in the
northwesterly flow on the backside of this low. Much of this smoke
will remain aloft, though there are hints that some could begin to
reach the surface by late Monday afternoon. Monday will continue to
be breezy, though not as windy as today with winds at the top of the
mixed layer running closer to 25 kts. With cold air advection behind
the overnight frontal passage, temperatures will remain below normal
with highs in the upper 60s to mid 70s.

A pretty significant jump in temperatures will come on Tuesday and
Wednesday as an upper level ridge over the western CONUS shifts to
the east. As 850 mb temperatures climb into the mid teens to lower
20s C on Tuesday, highs will climb well into the 80s - nearing 90
degrees through the James River Valley and westward. There will be
lower confidence in temperatures for Wednesday however, as a cold
front drop southward on Tuesday night - becoming nearly stationary
across our area on Wednesday. Where this front eventually ends up
will play a part in how warm temperatures get. As a result of more
uncertainty and a larger individual members ensemble spread,
probabilities for exceeding 90 degrees on Wednesday are little lower
with the latest 12Z runs - at 30-60% (highest in the south). That
being said, again depending on where the front settles across the
area this could be the warmest day of the week for areas generally
south of Interstate 90 - with a potential for lower to mid 90s.

The aforementioned front could be the impetus for shower and
thunderstorm development on Wednesday evening through Friday - this
as the front meanders over our area and a series of upper level
shortwaves track through the flattening upper level ridge.
Confidence in timing and exact location of showers and storms
remains low, dependent on frontal position and timing/location of
aforementioned waves. Midweek will be the time period to watch for
potentially strong to severe storms with CIPS analogs and CSU
machine leaning models indicating some risk of severe weather during
this time frame (Wednesday/Thursday). This unsettled weather pattern
could persist even into next weekend. While temperatures look to
remain above normal through the period - they will notch down a few
degrees over midweek highs.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1145 AM CDT Sun Jun 8 2025

MVFR visibilities in smoke will continue to improve through the
afternoon. Northwesterly winds will gust 25 to 35 kt through the
day, with isolated gusts around 40 kts. Isolated to scattered
showers could brush KHON and KFSD later tonight, with ceilings
lowering into the MVFR range north of Interstate 90.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory until 7 PM CDT this evening for SDZ038-052-053-
     057>059.
     Wind Advisory until 7 PM CDT this evening for SDZ054-060>071.
MN...None.
IA...None.
NE...None.

&&

$$

DISCUSSION...JM
AVIATION...JM