Chamberlain, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

746
FXUS63 KFSD 091105
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
605 AM CDT Mon Jun 9 2025

.KEY MESSAGES...

- Wildfire smoke aloft today may briefly surface again tonight
  into Tuesday, with some impacts to air quality possible.

- Periodic moderate (40-70%) chances for showers and storms
  Wednesday afternoon through Friday. There is some potential
  for severe storms and locally heavy rainfall Wednesday and
  Thursday, but confidence is very low in details at this time.

- Breezy and cooler than normal today, but warmer air builds in
  mid week with highs mainly in the 80s to lower 90s. Late week
  temperatures becoming more uncertain due to potential impacts
  from multiple days of convection around the region.

&&

.DISCUSSION...
Issued at 410 AM CDT Mon Jun 9 2025

TODAY-TUESDAY: Sharp upper level low spinning slowly east across
Minnesota early this morning will gradually move east across the
western Great Lakes today, before lifting into Ontario/Quebec on
Tuesday. Trailing cold front is currently dropping south across
our forecast area. Mostly cloudy skies behind the front will
dominate much of today, but the moisture is rather shallow.
Expect rain chances to be limited to spotty sprinkles at best,
mainly in portions of southwest Minnesota where the cloud layer
has a little more depth along with very weak instability. While
not as windy as yesterday, expect breezy northwest winds gusting
25 to 30 mph.

Low clouds are expected to erode with sunset, but skies could
still be hazy due to lingering wildfire smoke aloft. Latest HRRR
smoke projections do indicate potential for light concentrations
reaching the surface tonight into Tuesday, so some minor impacts
to air quality are possible. Otherwise Tuesday will feature a
switch to southwest flow and a building thermal ridge which will
help pump temperatures into the 80s, with some lower 90s near &
west of I-29.

WEDNESDAY-THURSDAY NIGHT: A more active pattern returns mid to
late week over the northern Plains, however details are still
uncertain as run-to-run consistency among the models as been
less than ideal. Past several days have seen projections for a
northern stream wave to become more dominant and track slightly
farther south Tuesday night into Wednesday. This has suppressed
the surface front farther south with time, which has impacted
not only our temperatures mid-late week (trending not as warm
north of I-90), but also the location of favored rainfall
chances and potential strong to severe storms.

While there are still some differences, the latest models show
modest agreement in placing the low level boundary near to south
of U.S. Highway 18 by late Wednesday afternoon, pushing farther
south Wednesday evening as a wave slides east from the Dakotas
into southern Minnesota. Robust instability builds south of the
front into our far southern counties late Wednesday, with MUCAPE
values 1500-2000+ J/kg. Meanwhile, mid-level westerlies increase
north of the front, leading to strengthening deep layer shear
>40kt along and north of the boundary.

Greatest instability and shear are largely displaced from the
other, but there should be a narrow corridor where instability
and shear sufficiently overlap to support at least an isolated
severe threat late Wednesday afternoon-evening. Location of this
has shifted over the past several model cycles, but the latest
ensembles focus this area between I-90 and I-80, greatest near
the Highway 20 corridor, and SPC has outlined this area in a Day
3 Marginal (Level 1 of 5) risk, with large hail and isolated
damaging winds being the primary threats. Will also have to
watch for locally heavy rainfall as Wednesday night progresses,
as a growing warm cloud depth will support more efficient rain
processes and a moderate southwesterly low level jet impinging
on the boundary could support some training storms. Again, the
exact locations of the above-highlighted features are subject to
further changes, so continue to monitor the forecast/outlooks
for the latest updates.

Uncertainty only grows as we head into Thursday. Wednesday
night convection will likely impact the location of boundaries
which could focus the potential for additional severe storms
and/or heavy rain by later Thursday/Thursday night. Some model
solutions lift the 850mb front slightly northward to somewhere
in the I-90 to Highway 14 vicinity while others are much more
aggressive in pushing the 850mb boundary as far north as I-94.
In either case, the primary surface boundary would be displaced
south of these locations, which could maintain a potential for
additional strong to severe storms and locally heavy rain later
Thursday into Thursday night in some portion of our CWA.

FRIDAY ONWARD: Yet another wave sliding across the northern
Plains will support rain chances into Friday, but the upcoming
weekend looks to favor drier conditions with some warming as
upper ridging works back into the area.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 605 AM CDT Mon Jun 9 2025

MVFR ceilings this morning will gradually improve through the
afternoon, with VFR conditions then expected through the end of
the TAF period.

Areas of light surface smoke are forecast by this afternoon
into Tuesday morning. Isolated MVFR visibility is possible, but
expect most areas to remain 6SM or better.

Northwest winds will be breezy today, with occasional gusts to
around 25-30kt through 10/00Z.

&&

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

&&

$$

DISCUSSION...JH
AVIATION...JH