Area Forecast Discussion

KEY MESSAGES

- Low clouds will persist into Monday and may result in periods of reduced visibility along higher terrain.

- Steadier showers move in tonight and Sunday as far east as the James Valley before tapering off from north to south on Monday.

- Temperatures will remain below seasonal normals the next few days before returning to near normal readings Tuesday and Wednesday.

DISCUSSION

Issued at 1237 PM CDT Sat Sep 19 2026

An upper low will slowly translate from the Montana Rockies into Minnesota over the next couple of days. For now, it continues to eject shortwaves into the northern Plains while sfc high pressure is transitioning over southern Canada and the northern Great Lakes. This has placed this forecast area in a region of weak easterly flow, helping to bump up low and mid level moisture. The associated low clouds and drizzle or light rain are expected to persist in this regime through Monday morning. Adjusted overnight temps toward higher hi-res guidance with smaller diurnal fluctuations expected due to cloud cover. It's a known model bias to drag temps too low in this type of pattern.

As the upper low exits to the east on Tuesday and a weak upper ridge builds in, expect daytime highs to rise on southerly flow to closer to normal values. On Wednesday evening, a llj sets up with some additional shortwave energy as the upper ridge recedes. This means increasing chances for showers and thunderstorms Wednesday night.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1237 PM CDT Sat Sep 19 2026

Terminals KABR,KATY,KPIR,KMBG

MVFR/IFR cigs are expected to persist into Monday morning. Light rain will spread over central SD tonight and Sunday, reducing vsby to MVFR/IFR in heavier showers.

ABR WATCHES / WARNINGS / ADVISORIES

SD...None. MN...None.