textproduct: Sioux Falls

KEY MESSAGES

- Periods of rain return tonight into mid week, heaviest tonight into Monday. Accumulative amounts of 0.75" to 1.25" inches are expected for most areas through Wednesday night. Slightly higher amounts will be possible west of a Gregory to Mitchell to De Smet line. Locally heavy rain may lead to ponding of water.

- Breezy to gusty winds are expected on both Monday and Tuesday with gusts between 30 to 40 mph. Locally higher gusts (around 45 mph) will be possible across south central South Dakota.

- A brief funnel or two could be possible by Tuesday morning though confidence is low (<30%).

DISCUSSION

Issued at 218 PM CST Sun Nov 1 2026

CURRENTS & TONIGHT: Taking a look across the area, a dreary start to November continues as areas of low stratus and mid-level clouds sit over the area. While some thinning and southeast surface winds may help temperatures sneak into the upper 50s to mid 60s this afternoon, should see holes fill back in by this evening as warm air advection (WAA) strengthens. Similar to last night, decided the dynamics at play will likely slow cooling overnight so used a blend of the CONSshort and NBM to slightly increase temperatures to the mid to upper 50s. From here, the focus will then shifts towards the increasing rain chances (70%-100%) this evening and overnight. Looking aloft, a strengthening nocturnal LLJ along with increasing lift ahead of the approaching wave will likely spur bands of light showers starting this evening. Lastly, the SPG will continue to tighten heading into Monday morning leading to gusts between 30-40 mph throughout the day. With this the stage is set for Monday's Colorado Low.

MONDAY-WEDNESDAY: Looking into the new week, we're still on track for widespread rain on Monday as the developing Colorado Low lifts into central and eastern SoDAK from the Nebraska Panhandle. From here, not much has changed on the forecast front. Bands of light to moderate showers will develop during the morning hours giving us most of our accumulations. Still can't rule out a few isolated thunderstorms mainly across areas along and east of Highway-81 as about 300-500 J/kg of instability develops. A dry slot will gradually progress across the area from late morning to early evening potentially switching us over to drizzle or just mostly dry conditions temporarily. Next round of precipitation comes by Tuesday morning as the 850mb cold front and surface low progress through the area. Depending on how and if things develop around the surface low during this time, we might have to be on the look out for a few funnels given the enhanced stretching potential with the low and lower LCLs. This is particularly evident in the NAM and RAP13 NST which has scattered values in the 0.5 to 1.5 range.

A tight SPG will continue to promote breezy to strong surface winds on Tuesday with northwesterly winds behind the front producing gusts between 30-40 mph with isolated higher across southcentral SD. Otherwise, should see light showers hang around for most of Tuesday and into potentially Wednesday as the mid-level low continues to gradually rotate eastwards into Minnesota. Shifting gears to overall amounts, some lingering uncertainty remain on where the heaviest accumulations will occur. However, guidance has shown consistent enough signals for a widespread 0.75" to 1.25" inches through at least Tuesday. Nonetheless, there still could be an area of slightly higher amounts (1"-2"+) potentially west of a Gregory to Mitchell to De Smet line depending on how the low tracks through the region. Impact-wise, lower precipitation rates will keep the flooding concerns on the lower side through the period though localized ponding will be possible in the area of heaviest accumulation and low-lying spots. Lastly, the increased precipitation chances will trend conditions cooler through Wednesday. As a result, highs are expected to tumble from the 60s to low 70s on Monday to mid 40s to low 50s by Wednesday.

THURSDAY ONWARDS: Heading into the later parts of the week, quieter conditions return by Thursday as mid-level ridging progresses through the region. Next potential rain chances return by Saturday as a quick and compact wave dives across the northern plains. Otherwise, daily temperatures will continue to hover in a more seasonable range with highs mainly in the low to mid 50s and overnight lows in the upper 30s to low 40s.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 619 PM CST Sun Nov 1 2026

Currently a mix of VFR and MVFR ceilings across the entire region. Expect ceilings to gradually decrease as continued moisture and warm air advection work to thicken and lower the stratus already in place. Overnight and into Monday morning widespread IFR and LIFR conditions are expected as soundings indicate the boundary layer saturating down to near the surface. Though winds will likely remain too strong for true fog formation, ensemble guidance indicates a 20- 40% probability that visibility may fall to 2 miles or less at times.

With the lowered ceilings come light to moderate rain showers. Current radar shows echoes forming over central South Dakota. These will progress east through the overnight. A few stronger storms may produce lightning and brief heavy down pours. No severe weather is expected at this time as the better dynamics exist farther south over Nebraska and Kansas. But we will monitor for changes in risks. Around mid-day a dry slot looks to pivot through the region. This will reduce storms down to a light rain/drizzle if not cause them to cease for a time. This may allow ceilings to improve back up to MVFR in places. As moisture wraps around the low, rain will increase again from west to east near the end of the period.

Winds are southeasterly and beginning to increase. Overnight gusts of 15-25 kts are expected to gradually increase. Around daybreak winds will be gusting 25-30 kts with the strongest gusts east of the James River Valley and west of I-29. Gusty winds will prevail for the remainder of the period.

FSD WATCHES/WARNINGS/ADVISORIES

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