462
FXUS63 KFSD 280807
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
307 AM CDT Fri Jun 28 2024

.KEY MESSAGES...

- Rivers across the area have crested or are presently at crest.
  Expect rivers to slowly trend downward, even with any rain early
  this morning.

- A small threat for severe weather exists this afternoon over
  parts of northwest IA. An isolated strong storm will also be
  possible in central SD this evening.

- Below normal temperatures continue today into Monday, with the
  coolest temperatures Saturday through Monday.

- Stronger westerly flow aloft develops Monday through the end of
  the week which should bring a bit busier pattern next week.


&&

.DISCUSSION...
Issued at 305 AM CDT Fri Jun 28 2024

Showers and thunderstorms will roll across the area this morning,
but severe weather is unlikely as the convection moves into more
stable air. Two more pieces of energy move through the area today.
One will be over mainly northeast NE into northwest IA early this
afternoon. Any severe weather will remain isolated and somewhat
limited as the timing of the lower level front moves through fairly
quickly. Another piece of energy is the stronger upper level low
pressure which will dip into northern SD tonight and swing through a
stronger cold front. Some very isolated stronger thunderstorms will
be possible with the surge of colder air and wind would be the main
threat. Instability is not overly high at around 500 J/kg but very
strong mid and upper level winds could support some stronger wind
gusts at the surface. Temperatures will warm a touch ahead of this
colder surge with highs from the upper 70s to lower 80s.

High pressure slides through the area this weekend bringing well
below normal temperatures Saturday and Sunday. Highs Saturday will
be in the upper 60s to lower 70s with highs Sunday in the lower to
mid 70s. Low temperatures on Sunday morning may fall into the 45 to
50 degree range in some locations.

While temperatures remain below normal on Monday, they will rebound
back into the mid 70s to lower 80s in most locations, a touch warmer
in central SD. This is in response to a trough digging into the
Northern Rockies. Instability does try to rebound into the area, but
similar to yesterday we may see mainly sub severe showers and
thunderstorms late Sunday night into Monday, then a better chance
for severe weather Monday night as instability tries to build up the
Western High Plains into the area. Scattered showers and
thunderstorms remain Tuesday with the next better chance for storms
Thursday. Temperatures will likely rebound back closer to normal but
may come up just a touch short in many locations.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1115 PM CDT Thu Jun 27 2024

Area of showers with isolated thunder over northwest Iowa at
the start of the period will slowly shift east through daybreak.
Main focus will be on line of strong to severe storms in central
SD which will push east through areas near/north of I-90 through
the overnight into Friday morning. Expect this line to gradually
weaken as it progresses farther east, but may still be producing
40+kt gusts as it approaches the James River/KHON. Will carry a
few hours of thunder at KHON and KFSD as this line moves through
prior to 12Z Friday. Additional storms may develop ahead of a
cold front across northwest Iowa Friday late morning/afternoon
with a low (30%) probability for KSUX.

Stout southerly low level jet will produce areas of low level
wind shear through daybreak, though still seeing occasional
surface gusts to around 25kt as well. Cold front will bring a
wind shift to west and northwest winds as it progresses east
across the area on Friday.

&&

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

&&

$$

DISCUSSION...08
AVIATION...JH