Hartford, South Dakota Weather Forecast Discussion

800
FXUS63 KFSD 071939
AFDFSD
Area Forecast Discussion
National Weather Service Sioux Falls SD
239 PM CDT Sun Sep 7 2025
.KEY MESSAGES...
- Chances (~10-20%) for isolated to scattered showers and some
  storms begins tonight and persists through Monday. Some
  storms could be on the stronger side on Monday.
- Additional chances (20-30%) for showers and storms are
  possible towards the end of the week and weekend but details
  are uncertain at this time.
- Temperatures will remain near to above average in the upper
  70s and 80s for the week ahead.
- Could see smoke at the surface push east of the Missouri River
  Monday evening.
&&
.DISCUSSION...
Issued at 238 PM CDT Sun Sep 7 2025
High pressure continues to slide eastwards this afternoon. This has
slightly tightened low level pressure gradients, leading to
marginally breezy southerly winds across the area. At the same time,
high temperatures have warmed to the upper 60s to low 70s, making
for a wonderful Sunday afternoon! Things will begin to change during
the evening hours though as a weak shortwave trough strengthens warm
air advection (WAA) ahead of it. This will steepen mid level lapse
rates just enough to generate minor amounts of instability thanks to
weak moisture advection around 800mb. This looks to be just enough
to develop sprinkles to light showers generally along and east of a
Huron, South Dakota to Sioux Falls, South Dakota, to Storm Lake,
Iowa line. Should see any chance for rain push northeast of the area
before sunrise tomorrow morning. Low temperatures be much warmer
tonight thanks to persistent southerly winds, only falling down to
the 50s to possibly still sitting around 60F in south central South
Dakota.
The previously mentioned weak shortwave trough will finally push
into the area on Monday. The night`s WAA will push 850 mb
temperatures up to the teens aloft. Mixing these temperatures to the
surface will result in a return to near to slightly above average
temperatures across the area in the upper 70s and 80s. The warmest
temperatures will occur west of the James River where a few
locations could make a run at 90F. At the same time, Monday will be
a breezy day with southerly winds gusting up to 20-30 mph. Chances
for rain look to be near zero through the first half of the
afternoon as the best forcing for ascent will be east of the area.
At the same time, a weak boundary also looks to be pushing east of
the river during this same period of time. There could be just
enough convergence along the boundary to result in a shower or storm
developing on it, especially given amply instability values in
place. However, this is a low probability (~20%) at this time given
the capping that is in place. Should a storm develop on this
boundary, then it could be a stronger one thanks to the instability
in place. Don`t think it will be severe though given margin The same
chances for weak showers will persist through the overnight hours as
weak WAA remain in place. To go along with the chances for rain,
smoke will be pushing in aloft throughout the day. Surface smoke
looks to remain west of the Missouri River Valley though the
afternoon hours but could push east of the river during the evening
hours. Low temperatures will remain on the warm side, only falling
down to the upper 50s and 60s.
The previously mentioned shortwave trough will begin to push east of
the area on Tuesday. With subsidence on the back side of the wave,
Tuesday looks to be mostly dry with the exception of locations east
of I-29 where another ~20% chance for rain will linger through the
day. Highs will remain near to above average in the upper 70s and
80s.
Upper level ridging looks to build into the Northern Plains for
Wednesday through Thursday. This will keep temperatures near to
above average in the upper 70s and 80s with lows only falling to the
60s. With upper level ridging in place, dry conditions are likely.
The ridge axis will begin to slide east of the area on Friday,
allowing heights to begin falling aloft. This will result in slowly
increasing chances for rain Friday through the weekend, especially
as a stronger upper level trough over the Rocky Mountains will push
eastward. The ensembles weakly show this as they show increasing
probabilities up to a 20-30% chance for rainfall totals to exceed a
tenth of an inch. Aside from rain chances, high temperatures will
remain near to above average in the 80s.
&&
.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1215 PM CDT Sun Sep 7 2025
VFR conditions are expected for the TAF period. Light southeast
winds prevail early this afternoon with speeds of 5 to 10 knots.
Should see winds strengthen just a little bit more during the rest
of the afternoon hours. Winds will remain elevated to even
marginally breezy this evening and night as the low level jet (LLJ)
strengthens. The LLJ could result in sprinkles to very light showers
but have omitted from all TAFs at this time given remaining
uncertainty in strength and specific location of any showers. The
LLJ will also result in weak low level wind shear (LLWS) at KSUX
tonight. Breezy southerly winds will finish out the TAF period
tomorrow.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.
&&
$$
DISCUSSION...Meyers
AVIATION...Meyers

NWS FSD Office Area Forecast Discussion