366
FXUS63 KFSD 162330
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
630 PM CDT Wed Jul 16 2025

.KEY MESSAGES...

- There is a low chance for light rain showers/sprinkles late
  this afternoon, mainly north of I-90. Any accumulation will be
  a couple hundredths at best.

- Decreasing clouds this evening and overnight with partly
  sunny, dry, and cool conditions on Thursday with afternoon
  highs in the low to mid 70s.

- Shower and thunderstorm chances of 30 to 60 percent return
  Friday and Friday night.

- Near daily 20-30 percent precipitation chances this weekend
  into early next week, although predictability is low.
  Temperatures will rise to near or above 90 degrees in many
  locations by next Tuesday.

&&

.DISCUSSION...
Issued at 236 PM CDT Wed Jul 16 2025

Late this afternoon, a few stray light rain showers/sprinkles
are possible mainly north of I-90. Any accumulation should be no
more than a couple hundredths. Clouds will then be slow to move
out late evening and overnight, but model soundings suggest
increasing sun through the day on Thursday as surface high
pressure settles across the region. Temperatures will be a bit
warmer than today, but still a solid 10 degrees below mid-July
normals with highs in the low to mid 70s.

Southerly surface return flow increases Thursday night into
Friday as high pressure slides eastward. This will allow for
increasing temperatures/moisture with afternoon dewpoints back
into the upper 60s to low 70s. As a result, MUCAPE soars upwards
of 3000 J/kg depending on the model, but very strong heating in
the 5-10 kft agl layer also results in a stout cap. 12Z model
suite suggests a weak wave in quasi-zonal flow aloft Friday
afternoon/evening, which may be enough to break the cap, or at
least result in some elevated thunderstorms. For now, increasing
POPs through the day on Friday, peaking in the 30-60 percent
range in the evening seems reasonable.

Precipitation predictability this weekend into early next week
remains quite low given messy synoptic pattern. 500 hPa heights
build through this period, but periodic ill-resolved short-waves
may be enough for near daily convective chances. Questions
abound concerning timing/coverage of any thunderstorms, so will
keep with the idea of broad-brushed 20-40 POPs. This pattern,
however, does favor increasing temperatures. GFS/ECMWF ensembles
show a 50-70 percent chance for afternoon highs to rise above
90 degrees for much of the southern and western portions of the
forecast area by Tuesday.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 625 PM CDT Wed Jul 16 2025

Mostly MVFR conditions will continue into Thursday. Taking a
look at satellite imagery, a blanket of stratus continues to
sit over the area late this afternoon promoting MVFR ceilings.
While these conditions will likely persist into the overnight
hours, expect the stratus shield to gradually erode by Thursday
morning with VFR ceilings return for the rest of the day as a
surface high arrives. Otherwise, light northerly winds overnight
will veer through Thursday morning becoming more southwesterly
by Thursday afternoon. Lastly, could see some patchy areas of
fog develop overnight as winds lighten up. However, confidence
in this is low at this time.

&&

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

&&

$$

DISCUSSION...Rogers
AVIATION...05