textproduct: Aberdeen

KEY MESSAGES

- Light rain moves as far east as parts of the James and Big Sioux Valleys tonight. Rain tapers off from north to south on Monday. There will be a brief break on Tuesday before rain returns Tuesday night and continues off and on through the work week.

- Temperatures will remain near to slightly below seasonal averages through Tuesday before climbing above normal toward the middle of the week.

DISCUSSION

Issued at 1237 PM CDT Sun Sep 20 2026

Easterly sfc flow is almost staving off movement of the rain past the Missouri River this afternoon. There is a pocket of drier air at the midlevels that is helping to hold the rain west river even with ample llm in place. All of that effort will be for nought as the upper low slowly makes its way east through South Dakota tonight. As it sinks south and east Monday, the precip will exit with it.

Once again, the NBM is likely too high with its overnight lows given the cloud cover and rain expected. All hi-res models keep lows in the low to mid 50s (except in west central MN where some scattering is possible), but did not blend toward them today in deference to neighbors and because of the chance for scattered cloud cover in the northeast. Expect clearing through the afternoon Monday from north to south as the system exits.

Return flow winds shift back to the southeast and south on Tuesday ushering in some warmer air. Skies should be mostly clear which will also help push temperatures above average. That said, models have shifted the upper level trends a bit for Tuesday moderating the upper ridgeand leaving some remnant shortwave energy around which could increase clouds, especially along the Coteau. There's now also a llj developing Tuesday night so can't rule out a shower or two early Wednesday. A 30 kt llj spreads over the region Wednesday afternoon and increases Wednesday night. There is some shortwave energy around, though it doesn't align perfectly. But, the ample mid level moisture should still allow for some showers and thunderstorms to develop. A 700 mb low could help amplify the precip probs through Friday night.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1237 PM CDT Sun Sep 20 2026

Terminals KABR,KATY,KPIR,KMBG

MVFR/IFR cigs will prevail with brief VFR breaks through Monday morning. Rains progresses east tonight affecting KMBG and KPIR with MVFR/IFR vsby at times before exiting from north to south Monday morning.

ABR WATCHES/WARNINGS/ADVISORIES

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