textproduct: Sioux Falls

KEY MESSAGES

- Periods of scattered showers with isolated thunderstorms will return by Saturday. While a low chance for a stronger storm will be possible by Saturday evening, some lingering uncertainty continues.

- Elevated fire concerns will return by Sunday as unseasonable warmth returns along with breezy westerly winds. This along with near-critical RH values (20%-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 storms. However, some details remain uncertain.

UPDATE

Issued at 339 AM CDT Fri Apr 10 2026

Stratus continues to slip southward and fragment. The models are pretty agreeable on this trend continuing so by 12-15z most locations will out of the clouds and a sunny and pleasant Friday is expected. The latest ensemble output from the GEFS, Canadian and ECMWF continue to point to lower rainfall amounts through early next week with the 50th percentile closer to a quarter to a half an inch in most locations east of the James River. With a few thunderstorms expected s few local locations could see more of course, but the overall trends are for more scattered activity starting on Saturday.

DISCUSSION

Issued at 227 PM CDT Thu Apr 9 2026

We've seen some widely scattered showers moving across the area today, and this will continue to be the case through the early evening. Some snow or sleet may mix in north of I-90 late this afternoon/early this evening as we wet bulb down, but impacts are not expected outside of wet roads given above freezing ground temperatures. Additionally, an isolated thunderstorm cannot be ruled out over northwest Iowa during the remainder of the afternoon, but severe weather is not expected. High pressure moves across the area tonight as clouds and precipitation move off to our east. Areas that saw precipitation today could see some light fog develop as winds turn light to calm and skies clear out. Look for lows tonight in the 20s across the area, though can't rule out some spots along Highway 14 especially east of I-29 dropping into the upper teens given skies will clear there first overnight.

Quiet weather expected for Friday and it will also be warmer with highs in the mid to upper 50s across the area. Warm air advection increases Friday night, which could result in widely scattered showers heading into daybreak Saturday. As we continue to pull in moisture into the day on Saturday, additional showers and even a few thunderstorms look to develop as daytime heating occurs. Instability looks limited during the daytime hours on Saturday; however as we head into the evening, the low level jet (LLJ) looks to strengthen and will help funnel in warmer and more humid air. This could lead to around 1000 J/kg of MLCAPE and thus an isolated stronger storm with some hail is possible Saturday evening; so this will be something to keep an eye on. With all this southerly flow in place, look for highs in the 60s and 70s on Saturday, warmest in south-central South Dakota. Saturday also looks to be breezy with gusts to 35 mph; however with the surge of moisture expected within the southerly flow, relative humidity values look to be well above critical levels.

A negatively tilted trough ejects across the northern Plains on Sunday, with a surface low developing across the Red River Valley. At this point we could get some showers and an isolated storm from this mainly east of I-29, though it looks like precipitation won't become more widespread until after this system passes us to the east. With that said, it will allow for us to be in west- southwesterly flow through the day on Sunday. This will mean a very warm day with drier air moving in. Look for highs in the upper 70s to mid 80s with relative humidity values dropping into the 20-30% range west of I-29. Winds won't be as strong as Saturday, but it still looks breezy with gusts to around 30 mph possible. This means Sunday will be a day to watch for elevated to potentially critical fire weather concerns.

A deep upper trough hanging out near the Pacific Coast will finally begin to move eastward heading into early next week, keeping inclement weather in the forecast for Monday and Tuesday. The eastern half of the area is currently highlighted in a 15% risk for severe weather by the Storm Prediction Center, and then we are just outside a 15% risk to our southeast for Tuesday. The upper level support will certainly be there with the aforementioned trough expected to eject across the area, so it will be up to the finer mesoscale details before the exact severe threats (wind, hail, etc.) can be determined. Ensemble probabilities of surface CAPE greater than 1000 J/kg for areas east of the James River ranges from 40-70% chance according to the NBM and the Canadian ensemble to a 20-50% chance according to the GEFS Monday afternoon. These higher probabilities shift farther south and east for Tuesday afternoon, but still include portions of northwest Iowa. Be sure to keep up to date with the latest forecast!

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 610 AM CDT Fri Apr 10 2026

Patchy MVFR and IFR conditions in stratus and patchy fog are expected through mid morning. The better chance for fog will be near and west of I-29. Otherwise high pressure at the surface will bring lighter winds, sunny skies and VFR conditions. Late tonight scattered showers and isolated thunderstorms will develop with the better chances near and east of I-29.

FSD WATCHES/WARNINGS/ADVISORIES

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