802 
FXUS63 KFSD 310316
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
1016 PM CDT Wed Jul 30 2025

.KEY MESSAGES...

- Below normal temperatures settle in through early next week.

- Some smoke mainly aloft will be possible the remainder of the
  week.

- Sunday should be the next chance for a few severe storms but 
  for now this threat appears to remain isolated. 

- Tuesday night appears to be the next chance for severe storms
  after Sunday with what looks to be a bit better chance for 
  scattered severe storms. However, uncertainty remains in the 
  coverage and severity with this potential activity.

&&

.DISCUSSION...
Issued at 222 PM CDT Wed Jul 30 2025

Today should be the final day of the deeper moisture that has been 
aiding in producing almost daily thunderstorms across the area. A 
weak MCV will continue to weaken in southeast SD this afternoon. 
This should be the focus for a few showers and thunderstorms. The hi-
res models that have this suggest the an storms that develop should 
be mainly south of I-90. That area has had quite a bit of rain the 
past week. Storm motion looks pretty slow and model soundings have 
relatively weak CAPE (500-1000 J/kg) with the freezing level around 
12-13 kft, so likely some efficient rainers. The HRRR and ARW seem 
to be handling things best thus far. The Nam 3KM and NSSL have 
convection in northwest IA from 12-15z this morning which is not 
happening so they are being ruled out. The models handling the MCV 
better are producing a small area of 1-3", possibly up to 4" which 
would fall over a short period of time with the focused area south 
of I-90 in far southeast SD then into northwest IA. For now the 
better chances will be between Sioux Falls and Sioux City, but will 
monitor for any changes in this subtle, weakly forced environment. 
Along with the threat for pockets of heavy rain will be a few funnel 
clouds. Winds in the lowest few thousand feet are very light and a 
weak boundary is also in place in far southern SD and northwest IA 
along with very low LFC/LCL. All of this hints that a few funnels 
are likely during the initial updraft phase but for now production 
of a tornado looks unlikely.

Any shower and thunderstorms activity should pretty much follow the 
diurnal cycle with most activity done by 10 pm to midnight. Through 
the night drier and more stable northeast flow will bring quieter 
weather Thursday into Friday with seasonally cool temperatures. 
Highs will be in the 70s to around 80 with lows in the 50s to near 
60.

On Friday night troughiness to the west develops and swings a mid 
level wave into central SD. The LLJ increases with a focus more to 
the west of the area, but this forcing does creep towards the James 
Valley. Overall instability looks pretty low so only very isolates 
severe is expected. 

Saturday into Saturday night continues to indicate a decent LLJ into 
the area with troughiness and a mid level wave rotating through. 
This will keep chances for showers and thunderstorms in place, but 
the severe threat continues to look very isolated.

Sunday will continue the chances for showers and thunderstorms with 
a slight increase in the threat for a few severe storms. The upper 
level troughiness begins to slip eastward with a bit stronger 
northwest flow aloft providing a bump in shear. Will continue to 
monitor trends with upcoming model runs.

Thunderstorm chances continue into early next week. There may be a 
lull Monday night into Tuesday, but by Tuesday afternoon into 
Tuesday night a stronger jet/wave moves onto the Northern Plains 
and could bring the next better chance for scattered severe storms.

Temperatures Tuesday into Wednesday will climb back to around
normal.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1013 PM CDT Wed Jul 30 2025

Light rain continues to move southeast and away from the area.
In the wake of this rainfall, scattered MVFR fog or smoke
continues to linger and drift southeast under a scattered to
broken mid-lvl deck.

Clouds will linger through the night with a continuation of
fog/smoke into Thursday. It's not impossible to see a brief high
MVFR stratus deck try to filter south through daybreak as well.

Thursday will feature northeast winds, with afternoon CU
developing. A non-zero chance for a diurnal shower is possible,
though too low to indicate in current TAF. Slight visibility
reductions from smoke continue. 


&&

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

&&

$$

DISCUSSION...08
AVIATION...Dux