textproduct: Sioux Falls

KEY MESSAGES

- Warm and predominantly dry conditions continue through the rest of the work week. However, chances for rain (20-50%) are possible from late Thursday into Friday mainly east of I-29.

- Warm, dry, and breezy conditions look to lead to elevated fire danger concerns on Saturday.

- Better rain chances (20-50%) and cooler temperatures look to return early next week, but confidence in details remains low.

UPDATE

Issued at 902 PM CDT Wed Oct 7 2026

No major changes to the forecast for tonight. Mid to high level clouds are streaming in a bit faster than expected, but this shouldn't have a huge effect on the going temperature forecast for tonight. Blended in the RAP for morning lows Thursday and this raised the temperature by maybe one degree in a few spots but left most areas unchanged. So still looking at lows Thursday morning in the middle 40s to lower 50s.

Soundings show some saturation within the DGZ as clouds continue to filter in late tonight, with the RAP even showing some elevated instability within this layer. Current thinking is that this will result in some virga if anything as there is a dry sub cloud layer that is rather steep, but can't entirely rule out a sprinkle or two along the Highway 14 corridor into southwest Minnesota late tonight into early tomorrow morning (<20% chance).

DISCUSSION

Issued at 153 PM CDT Wed Oct 7 2026

Quiet conditions persist across the area early this afternoon. High temperatures have warmed to upper 60s and 70s with mainly clear skies and light to marginally breezy winds. The pleasant conditions will persist for the rest of the afternoon so get there and enjoy it! Low temperatures will bottom out in the 40s to just about 50F overnight.

The daylight hours on Thursday will see a continuation of warm and quiet conditions with highs warming back to the upper 60s and 70s. Winds will turn to out of the south but still remain light to marginally breezy with gusts up to about 20 mph or so. The next chance for light rain looks to return to the area Thursday evening and night as a weak shortwave trough pushes into the area and strengthens low level warm air advection (WAA). The WAA will steepen mid level lapse rates just enough to result in minor instability on the order of 200-500 J/kg of CAPE. With enough elevated moisture and lift in place, scattered showers with an isolated storm or two is on the table. Chances (20-50%) for rain will persist through the night with the highest values residing east of I-29. Rainfall amounts are expected to be light at a few hundredths to up to about a tenth of an inch.

Friday will be another dry day across the area with high temperatures further warming to the upper 70s and 80s across the area. The warm highs will be accompanied by marginally breezy southerly winds. Low temperatures will also be on the warm side due the southerly winds, with lows only falling to the 60s. This is supported by the ensembles as they show an 80-100% chance for low temperatures to remain at and above 60F. With such warm overnight lows in place, they could rival record warm low temperatures. Something to keep an eye on going forwards.

The thermal ridge axis will push into the area aloft on Saturday, leading to the warmest high temperatures into the 80s. The southerly winds will be much stronger throughout the day with winds gusting up to 30-40 mph. This is supported by the european ensemble as it shows a 50-90% chance for gusts to exceed 30 mph. The warm conditions will be met with lower dew points, down to the 50s. This looks to result in lower humidity values down to about 30-40% across the area. The lowest humidity values look to reside along and west of the James River. Could see humidity values further over the next day or so. With stronger winds, warm temperatures, and low humidity in place, elevated fire danger looks to make a return to the area. The main uncertainty about this potential is fuels. Recent rainfall has kept grasses green so will have to see how much drier fuels get heading into Saturday. Slowly weakening southerly winds will keep warm overnight lows in place, with lows falling to the upper 50s and 60s.

A cold front looks to push through the area on Sunday, potentially resulting in cooler high temperatures and weaker northwesterly winds in its wake. However, this potential will depend on how quickly the front pushes through the area. Medium range guidance shows a large variance in how fast the front will push through the area. Will watch trends in the fronts progression to see if adjustments to the forecast is warranted.

A potentially more active pattern may return to the Northern Plains for the first half of next week. Medium range guidance continues to show a large variance in how the upper level pattern will evolve. The ensembles paint a clearer picture with an incoming longwave trough cutting off over the southwest CONUS before ejecting eastwards on Wednesday into the Plains. The ensembles show a 20-50% chance for rainfall total to exceed a tenth of an inch, with the highest values coming next Wednesday. Details can still change but this looks to support more rain chances and cooler temperatures for next week.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 622 PM CDT Wed Oct 7 2026

VFR conditions will prevail through the period. Similar to yesterday, can't rule out visibility reductions in any dust/haze kicked up from any nearby agricultural activity, but with lighter winds in place, this will remain brief and highly localized.

Can't rule out a sprinkle or two along the Highway 14 corridor late tonight into tomorrow morning, but otherwise we are dry. Winds will be mainly light and variable tonight, picking up slightly out of the southeast Thursday afternoon around 5-10 kts, though a bit higher to 12 kts in south-central South Dakota.

FSD WATCHES/WARNINGS/ADVISORIES

SD...None. MN...None. IA...None. NE...None.