textproduct: Sioux Falls

KEY MESSAGES

- Dry through Mid-Week With rain returning Wednesday night into Thursday: Near normal temperatures likely through Wednesday. Scattered rain by Thursday with a 40-70% probability of greater than 0.10" of rain.

- Turning Colder: Temperatures Thursday and Friday fall below normal with highs in the 50s and low 60s. Frost potential on Saturday morning.

- Warming trend possible Sunday into early next week.

DISCUSSION

Issued at 108 PM CDT Mon Oct 12 2026

A fast moving wave will exit the area late this afternoon into the evening. A few sprinkles or patchy drizzle will be possible, but impacts will be minimal. Otherwise the challenge will be stratus development with dissipation through the afternoon into the evening and then further redevelopment overnight into Tuesday morning. Even with a few locations possibly falling into the upper 30s, a north wind of 5 to 10 mph and cloud cover will likely limit any frost development.

Another wave will move through NE on Tuesday and could bring a stray showers into parts of northeast NE and northwest IA, but once again, amounts will be light and impacts minimal. With some cloud cover and a cool northerly breeze, temperatures will remain around normal.

Wednesday will be mild and dry as upper level ridging builds ahead of the next stronger wave. High pressure at the surface will see lighter winds and temperatures around normal.

The next stronger wave moves into the area Wednesday night into Thursday. Warm advection increases in the lower levels ahead of this wave Wednesday night which will bring the potential for some rainfall. The stronger warm advection is more likely across NE and expect the better rainfall amounts to remain there as well. Instability looks very weak so thunderstorms are unlikely. Currently the better chance for a more meaningful rainfall (0.25" to 0.50") is south of I-90 on Thursday during the day. The latest GEFS and EC Ensemble are indicating a 20-40 percent chance for more than a half an inch of rain south of I-90.

Saturday morning will see cool surface high pressure settle south, bringing a chance for frost across the area. Some hints that southerly return flow may set up through the night so confidence on frost development remains a bit low.

A warming trend is looking more likely Sunday into early next week as faster westerly flow aloft transitions to upper level ridging through mid week. This will allow for a well mixed environment Sunday and Monday, with southerly flow becoming more dominant mid to late week. Some hints that a cool front may slip south on Monday, but the effects on temperatures would not be real strong. This is still 6-10 days out, so lots of room for changes, but for now looking like a good chance for near to above normal temperatures Sunday through the middle of next week.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1250 PM CDT Mon Oct 12 2026

VFR conditions prevail east of I-90 to start the period, while IFR/LIFR persist to the west, separated by a frontal gradient. The front continues a slow eastward push bringing MVFR across eastern areas. Localized IFR remains possible post-front if westerly flow does not break up the cloud deck. Winds will remain variable along the boundary before shifting to a broad northerly flow across the CWA by the end of the period.

FSD WATCHES/WARNINGS/ADVISORIES

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