517
FXUS63 KFSD 131718
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
1218 PM CDT Thu Jun 13 2024

.KEY MESSAGES...

- Scattered showers and thundershowers will continue to move
  across the area through the early afternoon mainly north of
  I-90. Accumulations up to a tenth are expected for most areas
  with isolated pockets of up to a quarter inch possible.

- Near to above normal temperatures will continue into the new
  week with daily highs expected to peak the upper 70s to 80s.

- Confidence continues to increase in more widespread rain
  chances (60%-80%) returning by Saturday with periodic chances
  for additional rain continuing into the early parts of the
  next week.

&&

.DISCUSSION...
Issued at 315 AM CDT Thu Jun 13 2024

The Short Term (Today & Tonight):

A slightly cooler day will be on tap for the day. Taking a look
across the area, mostly clear conditions continue as most areas
sitting in 60s to low 70s this morning. Looking to the northwestern
portions of South Dakota, a few light to moderate showers with some
embedded thunder have begun to develop along an Aberdeen to Mobridge
to Buffalo line in response to a subtle shortwave moving across the
state this morning. The general consensus among deterministic
guidance has this developing line of showers and thundershowers
pegged to gradually drifting southeastwards into the Hwy-14
corridor around daybreak (09-12z) and areas north of I-90 by
mid-morning (12z-15z) before most of the activity exits our area
by the early afternoon. While we`re not expecting widespread
development with this activity, 200-400 J/kg of MUCAPE along
with ample shear aloft, could help create some heavier pockets
of showers within the developing line.

With this in mind, the general expectation is for up to a tenth of
accumulation for most areas north of I-90 with a few isolated
pockets of up to a quarter inch possible underneath heavier
pockets of convection. Otherwise, the combination of
strengthening mid-level cold air advection (CAA) and northerly
to northwesterly surface winds will keep our temperatures in
check for the day as highs peak in the low to mid 80s across the
area. Lastly, clearer and quieter conditions will return by
this afternoon as a surface high slides into our area from the
northwest. With lingering CAA aloft and winds expected to
decouple overnight, expect our lows to drop back into the low to
upper 50s for the night.

The Long Term (Friday-Wednesday):

Heading into the start of the weekend, heights will continue to rise
on Friday as the upper-level component of the ridge moves into the
region from the west providing a temporary return to quieter
conditions during the morning hours. Light and variable winds will
become more southeasterly by the afternoon and increase with gusts
up to 25 mph possible especially west of Hwy-81. Effective mixing
and southeasterly surface winds will help keep our temperatures
slightly above normal our seasonal normals as highs peak in the low
to mid 80s for the day. Our attention will then pivot to the
Colorado Rockies as a subtle shortwave and a mid-level trough lifts
northeastwards into our area from as early as Friday afternoon
through the day on Saturday bringing us our next widespread
precipitation chances (60%-80%). While there are still a few
lingering questions regarding the progression of the second wave,
the consensus among ensemble guidance has low to medium confidence
in at least an inch of QPF across portions of the area. Otherwise,
expect most of the activity to exit the region by Sunday morning as
quieter conditions return. Lastly, our highs will take a temporary
dip into the mid 70s to low 80s by Saturday but should rebound
nicely by Sunday as highs peak back in the upper 80s to low 90s.

Looking into the new week, long-range deterministic guidance begins
to diverge in potential solutions as Upper-level ridging strengthens
over the eastern CONUS shifting our area to southwesterly flow
aloft. Some deterministic guidance does show some decent potential
for periodic rain chances on Monday and Wednesday. However, with
variance in the placement of the inverted trough and subsequent
shortwaves among long-range guidance its too early to tell how
things will pan out. As a result, left the default NBM in for the
extended. Lastly, temperatures will continue to trend near to above
normal through Wednesday with highs expected to be largely in 80s
with a few low 90s possible across northwestern IA on Monday and
Tuesday.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1217 PM CDT Thu Jun 13 2024

A small strip of showers and thunderstorms is sliding eastwards
along the I-90 corridor east of Mitchell, which may bring some brief
MVFR conditions before exiting off to our east. The rest of the day
will see cloud coverage decreasing, with winds similarly decreasing.
With winds light and variable overnight, patchy fog may develop
during the overnight hours in low-lying areas along with river
valleys. Have left mention out of the this set of TAFs, but that`s
something to keep an eye on with future TAF updates.

&&

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

&&

$$

DISCUSSION...Gumbs
AVIATION...APT