Brookings, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

437
FXUS63 KFSD 112002
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
302 PM CDT Sat Apr 11 2026

.KEY MESSAGES...

- Elevated to critical fire danger is expected on Sunday. A Red
  Flag Warning has been issued for locations along and west of
  the James River where confidence is highest in critical fire
  danger conditions being met. The Warning is in effect from
  noon to 7 pm Sunday.

- Showers and storms remain in the forecast for the weekend.
  Chances for storms remains low (15-30%) with locations across
  northwest Iowa having the highest chances for seeing rain. A
  strong to severe storm is possible.

- Monday brings the best chances (30-60%) for strong to severe storms.
  However, there remain uncertainty regarding the location in
  where storms develop. Continue to check the forecast for the
  latest updates.

- Chances (30-50%) for showers and storms look to persist through
  the rest of the week. Details remain uncertain at this time.

&&

.DISCUSSION...
Issued at 300 PM CDT Sat Apr 11 2026

Warm advective rain showers have pushed off to the east this
afternoon. However, moist low levels has kept low level stratus
around. This has kept high temperatures in the mid 40s to mid 60s,
warmest across south central South Dakota. This is due to winds
taking on a south/southwest component across south central South
Dakota, resulting in clearing the stratus across this area. Breezy
winds will be persistent though and last through the overnight
hours. With breezy winds and stratus in place, only have low
temperatures falling to the 50s across the area. There remains the
possibility of a rouge storm or two late tonight. Should a storm
develop, it would be across parts of northwest Iowa. This seems
unlikely (15% chance) as of now as warm air advection (WAA)
strengthen aloft without advecting sufficient moisture with it. This
will lead to an increasing cap above the moist stable later. If a
storm can form, then it would have the potential to be strong to
severe given sufficient

Low level winds will turn westerly for the day tomorrow and remain
breezy. High temperatures look to significantly warm into the upper
70s and and low 80s across the area. With drier westerly flow in
place, humidity levels will drop, resulting in critical fire danger
being reached. More details can be found in the fire weather
discussion below. The westerly winds will advect drier air into the
area throughout the day. However, guidance is persistent in showing
this drier air shoving the better low level moisture all the way
down to portions of northwest Iowa. This moisture boundary would be
the location for a rouge storm to develop on. However, a weak
shortwave trough will already be east of the area, promoting
subsidence on its backside. Thus, Sunday looks to be mostly dry
though there remains the outside chance (15-30%) that a few showers
or storms develop along and southeast of this boundary. Any fire
danger will come to an end during the evening hours as the boundary
layer stabilizes. WAA will restrengthen aloft ahead of an incoming
exit region of an upper level jet tied to a shortwave trough.
Moisture looks scarce above 900mb and with the WAA strengthening the
low level inversion. Again, the potential for any showers remains
low at 15% or less through the night. If a storm is able to form, it
could be strong to severe. Low temperatures will fall to the 40s and
50s overnight.

Monday looks to have the highest chances for strong to severe storms
as medium range guidance is in decent agreement in a shortwave
trough pushing through the Northern Plains. The mass response to
this wave will result in southerly return flow and moisten dew
points across the forecast area. With mid level lapse rates to above
8C/KM aloft. This will result in the potential for large buoyancy.
There remains some uncertainty though as some of the guidance shows
the bulk of the moisture getting advected to the east of the area.
This possibility would happen if the surface low races east of the
area and and introduces westerly surface winds on its back side. If
the incoming shortwave is slower aloft, then the surface low will
not quickly race off to the east and thus leave a broader warm
sector across the area. The other component to potential severe
weather is the cap. Latest guidance continues to support a strong
cap above the warm sector. At this time, the longer range CAMs such
as the RRFS, NAM3km, and FV3 do show convection firing along the
warm front. But, this front is just north of the area. With the mean
wind remaining out of the southwest, these storms would quickly push
off to the northeast. Latest REFS also suggests this solution as
well as convergence is strongest along the warm front north of the
forecast area. As of now, only the deterministic Euro, Euro
ensemble, and AIFS (AI Euro) show the warm front remaining draped
across I-90 and thus producing convection Monday afternoon. Think
the current SPC Day 3 outlook remains valid given this remaining
uncertainty.

The warm sector looks get shoved further south and east of the
forecast area on Tuesday. While the main wave will eject out of the
Rockies on this day, keeping severe storm chances around. If the
boundary remains off to the south and east, then storms chances
would be lower. If the boundary remains across the forecast area,
then storm chances would increase across the area. Tough to say which
solution is correct at this time but something to keep an eye on
over the next few days. The upper level pattern diverges towards the
middle and end of next week but additional chances for showers and
storms remain possible. Aside from rain chances, high temperatures
look to remain above average in the 70s and 80s through Friday.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1228 PM CDT Sat Apr 11 2026

MVFR/IFR stratus blankets the entire area early this afternoon.
Visibilities remain vastly VFR beneath the stratus. Should see the
stratus erode on its western flank and bring sunshine to locations
in south central South Dakota. However, the bulk of the area will
continue to see the stratus remain in place for the rest of the
daylight hours. A few light showers and drizzle remain possible. The
low level jet (LLJ) will strengthen tonight, bringing low level wind
shear (LLWS) to the entire area. There remains the possibility for
an isolated storm to two to develop late tonight across northwest
Iowa. Confidence is too low to include in a TAF at this time but
will keep an eye on this potential. The low level stratus will clear
the entire area through the overnight hours as winds take on a more
westerly component. Should see the stratus completely clear the area
by about mid morning tomorrow. This will leave breezy westerly winds
to finish out the TAF period.

&&

.FIRE WEATHER...
Issued at 300 PM CDT Sat Apr 11 2026

Temperatures are expected to warm to the the upper 70s and low 80s
across the area tomorrow. Dew points will lower to the 30s and 40s
for most locations outside of northwest Iowa. This will result in
humidity values down to 15-35%, lowest across south central South
Dakota. Winds will be strongest in the morning but remain breezy
with gusts up to 30 mph through the daylight hours. There remains
some uncertainty regarding the dryness of available fuels across the
area due to today`s morning showers and lingering drizzle. Although
low level winds are expected to turn westerly by tomorrow morning,
pushing today`s low level stratus out of the area. Confidence is
higher in this possibility (~60%+ chance). However, if the stratus
does not clear as quickly as currently expected, then temperatures
will be cooler and thus humidity will be higher. As of now, have
issued a Red Flag Warning for locations along and west of the James
River where confidence is highest in critical fire danger conditions
being met. The Warning is in effect from noon to 7 pm. Expansions to
the Warning is possible.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Red Flag Warning from noon to 7 PM CDT Sunday for SDZ050-052-
     053-057>060-063>065-068-069.
MN...None.
IA...None.
NE...None.

&&

$$

DISCUSSION...Meyers
AVIATION...Meyers
FIRE WEATHER...Meyers