textproduct: Sioux Falls

KEY MESSAGES

- Widespread rain continues this morning. Scattered showers and isolated storms expected this afternoon and evening. More widespread rain returns from west to east late tonight into mid week.

- Severe weather is not anticipated. However, there is a low risk of funnels and possibly a landspout east of US Highway 81 Monday afternoon into the early evening.

- Gusty winds are expected through Tuesday night with widespread gusts of 30-45 mph. Gusts around 50 mph possible Monday with showers and storms.

- By the time rain ends Wednesday afternoon, widespread totals of 0.50 to 1.00 inches are expected. Totals may approach or exceed 2 inches along and north of a Gregory to Mitchell to Marshall line.

UPDATE

Issued at 247 AM CST Mon Nov 2 2026

Given the handful of topics to cover in this update, have broken this discussion down by changes and weather concerns over the next 24-36 hours.

CURRENT CONDITIONS: Rain, moderate at times, continues to lift north this morning. Radar shows the heaviest across SD west of Winner toward north central SD. Through roughly 2:30 AM, rainfall amounts since midnight are around an inch or less, highest toward Huron and Mitchell. Winds are gusting out of the southeast around 20-35 mph and sustained 15-25 mph. Seeing some drizzle across the eastern portions of the area.

FORECAST CHANGES: Minor adjustments to pops through Tuesday morning to account for more recent hi-res guidance. Made adjustments to the winds and wind gusts as well, mainly impacting gusts through the morning Tuesday.

TODAY'S SEVERE RISK: Severe weather risk remains low today, and focused across the eastern two-thirds of the forecast area. High shear/low CAPE environment remains in place most of the day and into the evening ahead of the cold front, where the eastern portions of the forecast area remain relatively close to the triple point of the northern surface low. Stratus over the area looks to limit heating potential and southern convection may limit some of the later day moisture return.

That said, concern exists with funnels and possibly a landspout this afternoon into the early evening with convection near the front. Confidence is low in development. Increasing surface convergence near the front, increasing stretching potential, and localized PVA all aid in a favorable environment for at least funnel formation with lower LCLs. 0-3km CAPE from both the RAP and the HRRR is 75 J/kg or more, with lapse rates through the same layer around 6.5 deg C/km supporting an isolated threat. Greatest risk looks to be from 1 PM CST to roughly 5 PM CST (sunset) along and east of US Highway 81, with the threat moving east ahead of the cold front.

HEAVY RAIN/FLOODING RISK: Ensemble probability and deterministic guidance continued to shift the highest precipitation axis to the north and west, with the highest totals along/north of a Gregory to Mitchell to Marshall line. Additional (post 6 AM CST Monday) rainfall amounts through mid week generally 0.5" to 1", with amounts over an inch near/north of that Gregory-Mitchell-Marshall line. Could see some localized issues and rises on smaller tributaries, especially if heavier rain falls over areas that saw heavier rainfall Friday night and early Saturday. Otherwise, main concern remains ponding of water in poor drainage and low lying areas. Widespread flash flooding is not expected.

STRONG WINDS: Contemplated a Wind Advisory for portions of the forecast area today and into Tuesday morning. However, most of the hi-res guidance shows 45+ mph gusts today into this evening with the showers and isolated thunderstorms, remaining fairly progressive over the area. HREF ensemble mean is generally 40-50 mph as the rain tracks east through early afternoon, with most sites only seeing the stronger gusts for an hour or two. If trends change as some of the 02.06z guidance comes in, will re-evaluate. Thunderstorms or stronger showers may also mix down some stronger winds around 50-55 mph through this evening. Wind gusts may approach 45 mph across south central SD later today and again late tonight into early Tuesday morning.

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 /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1127 PM CST Sun Nov 1 2026

A mix of VFR down to LIFR ceilings will prevail for the first half of this period. Ceilings will continue to degrade to mainly IFR with periods of LIFR under showers and thunderstorms. Soundings indicate stratus will slowly lower as the boundary layer saturates, 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.

Light to moderate rain showers currently located west of I-29 will continue to move northeast through the overnight. A few stronger storms may produce lightning and brief heavy down pours. Severe weather is not anticipated. A dry slot pivots through the region beginning around mid-day over south central South Dakota. Showers and storms will lessen in intensity to light rain/sprinkles to drizzle, if not ceasing all together at times. During the afternoon ceilings are likely to improve back to MVFR before another round of wrap around showers moves in Monday evening.

Southeasterly winds are expected to increase overnight. By mid- morning winds will be gusting 25-35 kts with the strongest gusts east of the James River Valley and west of I-29. Gusty winds decrease temporarily ahead of the approaching cold front Monday evening.

FSD WATCHES/WARNINGS/ADVISORIES

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