547
FXUS63 KFSD 100214
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
914 PM CDT Thu Jul 9 2026

.KEY MESSAGES...

- Diminishing thunderstorms arrive late tonight, and could
  linger into daybreak Friday. Severe storms not anticipated.

- Outside of a very localized risk for thunderstorms late
  Friday afternoon over SW Minnesota and the Ridge areas of
  South Dakota, a dry forecast into next week is anticipated.

- Temperatures through the upcoming 7 days will trend warmer,
  with widespread highs in the 90s to near 100 through much of
  next week. 1-2 days may feature heat advisory conditions. The
  cumulative nature of the heat could lead to heat illness.

&&

.UPDATE...
Issued at 913 PM CDT Thu Jul 9 2026

Storms over western South Dakota continue to move southeast. As they
approach the western edge of our CWA they will encounter an
increasingly more stable environment. The best instability flows
along with the wave and moves to the southeast into central
Nebraska, and the storms are expected to follow along that gradient.
A few isolated, weakening storms may cross the Missouri River into
south central South Dakota. These are not anticipated to be severe
but could produce some small hail and wind gusts to 45 mph. Any
storms that make it across the river will quickly dissipate. We will
continue to see mid to upper level clouds flow in off the anvils of
these storms resulting in partly to mostly cloudy skies overnight
and into Friday. Lows tonight will be around average for this time
of year, in the low to mid 60s.

Early Friday morning another area of thunderstorms may develop along
a surface boundary in eastern North Dakota that will advance south
into eastern South Dakota and southwest Minnesota. An area of low to
moderate instability will fuel these storms. But lack of shear
will keep them more of a pulse type storm than supercellular.
Hail to the size of a quarter and wind gusts will be the primary
threats. Storms will rapidly dissipate by mid morning, however
the weak boundary/MCV may linger into the afternoon. Through the
rest of Friday clouds will gradually thin becoming mostly sunny
in the afternoon. Light and variable winds will become
southerly but remain light. By Friday evening the previously
mentioned lingering boundary/MCV will work as a focus for
another round of pulsy, possibly strong thunderstorms. Storms
expected mainly east of I-29 with threats of hail to the size of
a quarter and wind gusts to 60 mph.

&&

.DISCUSSION...
Issued at 143 PM CDT Thu Jul 9 2026

THIS AFTERNOON:  Quiet conditions are likely this afternoon as winds
remain light and variable.

TONIGHT:  Scattered convection that forms over the western High
Plains will begin to roll eastward through the evening hours as a
shortwave moves into the region. The majority of instability remains
bottled up over the West River areas through the evening, and as
convection slides eastward it`s likely to diminish quickly by
time it reaches the CWA. A few gusty winds with decaying showers
could still be possible into south central SD. The remnant area
of vorticity may drift into northern Nebraska, and could keep a
low risk for convection through daybreak in the MO River
valley.

FRIDAY:  A secondary area of convection may form over central ND
late tonight, and slowly drift into northeastern SD by mid-morning
Friday.  A potential MCV could linger into Friday afternoon over the
SD portions of the Buffalo Ridge, and with that area on the edge of
the low-lvl EML, can`t rule out isolated to scattered convection
forming after 4-5pm. From a parameter perspective, MLCAPE
values remain near 2000 J/KG, but effective shear is very weak,
suggesting only pulse strong storms with wind and brief hail
could be possible into SW Minnesota during the evening. As
instability pulls northward in the evening the severe weather
risk should diminish quickly. Elsewhere, a breezy southwest wind
will push highs into the upper 80s to lower 90s.

THIS WEEKEND: Mid-lvl heights begin to rise quickly as we head into
the weekend, which will begin a stead upwards rise in temperatures.
One thing to note in recent guidance is that surface winds Saturday
and Sunday remain more from the southeast and rather light, which
could hold down the extreme climb in highs suggested a few days ago.
We`ll also see a bit more mix down of dry air as soundings have also
trended a bit drier, this will allow afternoon dew points to fall
and keep heat index values below critical limits.

MONDAY-THURSDAY: A dry and hot week is expected in the region as a
600+ DM 500 mb ridge centers itself over the CWA.  The placement of
the ridge prevent any storm development, but allow temperatures to
climb through the 90s most days. Confidence is high that we`ll see
temperatures in the middle to upper 90s in most locations, with some
areas reaching 100 along and west of the James River valley. The EC
ensemble supports this idea with 60%+ probabilities along the James
River valley Monday-Thursday.  With afternoon dew points mixing down
at least into the upper 50s to lower 60s, this should prevent
widespread heat index readings over 100 degrees. While the day to
day numbers may not be extreme, the cumulative effect of the heat
could lead to health related strain by mid-late week.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 606 PM CDT Thu Jul 9 2026

VFR conditions are expected for the period. Winds will be light and
variable. Thunderstorms over western and central South Dakota are
forming mid to upper level cloud shields that will flow into the
region this evening and overnight. Storms are expected to weaken as
they enter our western CWA. While severe weather is not
anticipated a few isolated showers and storms are possible.
Confidence is too low that storms will impact any TAF sites to
be included at this time. Clouds dissipate through the day
Friday.

&&

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

&&

$$

UPDATE...AJP
DISCUSSION...Dux
AVIATION...AJP