textproduct: Sioux Falls

KEY MESSAGES

- After a brief break through the late afternoon, scattered showers will gradually spread eastwards overnight. Widespread accumulations are expected through Monday night with most areas west of I-29 seeing accumulative amounts of 1+ inches. Locally higher amounts will be possible west of the James River Valley.

- An active pattern aloft will lead to additional rain chances on Wednesday and potentially over the weekend. Monitor your local forecast if you have any outdoor plans

- Near to slightly above normal temperatures will return from Wednesday onwards with daily highs in the low to upper 60s with a few low 70s at times.

DISCUSSION

Issued at 155 PM CDT Sun Oct 25 2026

CURRENTS-MONDAY: Another dreary and wet day continues! Taking a look across the area, we're continuing to enjoy a brief break this afternoon as the rain shield lifts into northeastern SD and central SD. While these conditions will likely persist through late afternoon, should see a shift eastwards during the evening hours locking us into intermittent showers for most of the night. From here, should see rain coverage continue to expand into Monday morning as a developing mid-level low lifts out of the Nebraska panhandle into central and eastern SoDAK. Given the better lift and strengthening warm air advection (WAA) with the wave, pockets of moderate (and at times heavy) rain likely develop throughout the day mainly west of I-29. Otherwise, this will be a longer duration rainfall event (24-30 hours) so flooding concerns are not expecting. However, localized ponding in urban and low-lying areas will be possible at times especially where the heaviest accumulations develops.

Looking at overall amounts, most deterministic and ensemble guidance continues to show high agreement in areas along west of a Yankton to Sioux Falls to Windom, MN line being the focus for 1+ inches amounts during the period with some low to moderate potential (30%-50%) for locally higher (up to 2 inches) west of the James River Valley. As this activity continues to gradually lift northeastwards, could also see some convectively enhanced showers develop by Monday evening mainly along and east of I-29 as the dry slot lifts through portions of the area and some weak instability develops. Conditions should gradually clear from southwest to northeast starting as early as Monday evening. Lastly, a large temperature gradient will set up across the region on Monday due to the increased precipitation chances. As a result, daily highs will vary between the mid 40s to mid 50s in the wettest areas (west of the line) and mid 50s to low 60s in the driest areas (lower Missouri River Valley and northwestern IA).

TUESDAY & WEDNESDAY: Looking into Tuesday, any lingering showers should continue to taper off northeastwards during the morning hours bringing the return of quieter conditions. Cloud cover should gradually decrease west of I-29 as southerly surface winds return. This combined with a bit of lingering WAA will help temperatures slightly recover with highs expected to be in the low 60s to low 70s. A tightening SPG could also lead to some marginal breeziness in the afternoon with gusts between 20-30 mph expected. By Wednesday, could see the return of some scattered showers during the afternoon hours as a quick shortwave drags a cold front through the Northern Plains. However, any resulting accumulations would be light with most ensemble guidance showing low to moderate confidence (30%-50%) in measurable precipitation mainly east of I-29. Lastly, we'll see similar temperatures to Tuesday with highs peaking in the low 60s to low 70s.

THURSDAY ONWARDS: Heading into the extended period, quasi-zonal flow will return through about Friday before Upper-level ridging returns to the plains. Some medium to long-range deterministic guidance continues to latch on to some additional precipitation chances between Friday and Saturday. However, there are some timing discrepancies among guidance. We'll just continue to watch this period for now especially since its a big holiday for the kiddos. Otherwise, we'll continue to lean slightly above normal temperature- wise through Sunday with highs mainly in the 60s with some low 70s across northwestern IA at times.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 631 PM CDT Sun Oct 25 2026

Some light showers persist west of the James River early this evening. Conditions are currently mostly VFR with a few locations reporting ceilings down to MVFR levels. Expect these current showers to push eastwards and expand in coverage through the rest of the evening hours. Rain will persist through the night and the entirety of the daylight hours on Monday. Ceilings will lower to MVFR/IFR/LIFR levels in the rain, with the lowest ceilings occurring along and west of the James River. Visibilities look to lower to MVFR thresholds in the rain. Could see further reductions in visibility down to IFR levels in the heaviest rain. Winds will pick up out of the east tomorrow morning with gusts strengthening to 15- 25 knots. The breezy winds and rain will finish out the TAF period.

FSD WATCHES/WARNINGS/ADVISORIES

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