textproduct: Sioux Falls

KEY MESSAGES

- Periods of scattered showers with isolated thunderstorms will return this weekend. Isolated strong to severe storms are possible over mainly northwest Iowa early Sunday morning, with quarter sized hail as the main threat.

- Elevated to potentially critical fire concerns will return by Sunday as unseasonable warmth arrives along with breezy westerly winds. This along with RH values as low as 18-30% will lead to high to very high fire danger with the focus being west of I-29.

- Renewed chances for showers and storms return on Monday and Tuesday with the potential for a few stronger to severe storms. However, some details remain uncertain.

DISCUSSION

Issued at 230 PM CDT Fri Apr 10 2026

It's a fairly pleasant and sunny Friday afternoon across the area! Changes are on the way though; it will get warmer... but also a bit stormier. Warm air advection (WAA) increases tonight, helping to bring some showers into the area early Saturday morning. These showers will move into the Missouri River Valley at first and lift northeastward into Saturday morning. A few rumbles of thunder will be possible with this activity, but severe weather is not expected. With the return of southerly flow and cloud cover associated with the aforementioned showers, expect a much milder night tonight with lows in the upper 30s to low 40s.

Warm air advection showers will be ongoing Saturday morning especially east of I-29. These showers will push off to our east into north central Iowa and south central Minnesota through the early afternoon. Saturday will be warmer and breezy, but with showers around and increasing moisture due to continued southerly flow, the fire weather danger will be low. The only place where we could see elevated fire weather concerns Saturday afternoon would be over south central South Dakota where clouds decrease the quickest and thus it will be a bit warmer out that way. Off to our west, an upper wave will be moving across the Rockies and sending impulses our way. Additional showers and storms may develop overnight Saturday into Sunday as the low level jet strengthens, allowing for around 1000-1500 J/kg of instability to move across the area. Any storms will be elevated given the capped low levels, leading to large hail up to the size of quarters as the main threat if a storm can become severe. The better chances of an isolated severe storm will be over northwest Iowa early Sunday morning, right where the Storm Prediction has the area in a Level 1 out of 5 Marginal risk for severe weather.

A shortwave trough will move across the northern Plains on Sunday and in response, a low pressure system will move across the Red River Valley into southern Canada. West-southewesterly flow will return to area in the wake of this system and bring a punch of much drier air into the area, especially west of I-29. This is where relative humidity (RH) values will drop below 30%, with RH values as low as 18-20% possible in south central South Dakota. It will be breezy and warm, with wind gusts around 30 mph and highs into the 80s. All this will lead to elevated to potentially critical fire weather concerns for areas west of I-29, so Sunday will be a day to avoid outdoor burning. Winds look to decrease through the late afternoon, so this could limit the extent of the fire weather threat into Sunday evening, but keep in mind it will still be dry and warm.

The active weather pattern continues into Monday as a deep trough over the central West Coast begins to move eastward. Monday looks to have the better chances for severe weather compared to Sunday morning, though uncertainty remains especially with the location of storm development. The 10.12Z ECMWF has storms developing over our area, while the 10.12Z runs of the NAM and RRFS have storms not developing until east of the area. This is at least in part due to timing and placement differences in the position of a surface low, with the ECMWF slower with this and the NAM and RRFS being faster. These finer details will need to be ironed out before we could start looking into individual severe threats, though a slower solution would favor surface based storms while a faster solution would favor elevated thunderstorms. The parent trough will eject across the area on Tuesday, and this could potentially lead to another threat of stronger storms as yet another low pressure system moves across the region. A few showers may linger into Wednesday, but models diverge significantly from there. With no big pushes of cold air advection following any of these systems, we look to remain warm into much of next week with highs possibly staying the 70s even into Wednesday and Thursday of next week.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1216 PM CDT Fri Apr 10 2026

VFR conditions expected this afternoon and evening. Heading into the early morning hours on Saturday, CIGS will drop to MVFR and locally IFR levels starting along the Missouri River Valley and spreading northeastward through Saturday morning. This will come with scattered showers moving through the area, which could also drop visibility at times down to MVFR levels. Can't entirely rule out a rumble of thunder with this activity from roughly KSUX to KSLB, but chances are low (<20%).

Winds will begin increasing this afternoon in south central South Dakota, gusting to around 20 kts out of the southeast. These higher gusts will begin to spread eastward through the night, with increasing winds area-wide by the late morning/early afternoon Saturday. This is when we could see southeasterly gusts upwards of 25-30 kts as the period ends.

FSD WATCHES/WARNINGS/ADVISORIES

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