215 
FXUS63 KFSD 251949
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
249 PM CDT Thu Sep 25 2025

.KEY MESSAGES...

- Multiple days of above normal temperatures with little to no 
  precipitation expected through the middle of next week.

- Very patchy radiational fog will be possible on Friday 
  morning with low lying areas the most likely as well as parts 
  of northwest IA.

&&

.DISCUSSION...
Issued at 215 AM CDT Thu Sep 25 2025

A surface ridge of high pressure will move east of the area tonight 
as low pressure develops over northern parts of the Western High 
Plains. This will allow for another cool morning on Friday with 
lighter winds much of the night, especially east of I-29. This will 
once again allow for some patchy fog. The impacts from this fog 
should be very localized. Otherwise, as we continue to see little to 
no precipitation and above normal temperatures the diurnal spread of 
temperatures is increasing a bit, thus forecast lows have been 
coming in a bit cooler and highs a bit warmer with the dry or drying 
ground.

With this in mind, as southerly flow increases ahead of a wave 
moving through southern Canada a strong warm nose will push into the 
area. The 850 mb temperature will be in the upper teens C in 
northwest iowa and the lower 20s C in central SD. This supports 
highs near 90 in central SD and lower to mid 80s in northwest IA. 
Those temperatures are about 10 to 15 degrees above normal.

Friday night a cool front will settle into the area and bring high 
temperatures a little closer to the seasonal normals. Highs will 
generally be in the 70s with a few lower 80s in and near northwest 
IA. The atmosphere continues to look too dry to support any showers 
or thunderstorms with the frontal passage.

Saturday night into Sunday an upper level ridge will build, bringing 
back the much above normal temperatures. Upper level high pressure 
locks into place across the mid Mississippi Valley, keeping any jet 
energy mainly west of the immediate area. This supports much above 
normal temperatures through at least mid week, with some hints that 
this ridge will break down by Thursday or Friday next week. Not 
currently thinking a major cool down as the ridge breaks down, but 
temperatures would settle back closer to normal.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1155 AM CDT Thu Sep 25 2025

VFR through the period. Southerly winds will increase on Friday
morning, bringing a few gusts around 20 mph west of I-29 towards
the end of the TAF period.

&&

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

&&

$$

DISCUSSION...08
AVIATION...08