textproduct: Sioux Falls

KEY MESSAGES

- Additional shower and very isolated thunderstorm chances are possible Monday afternoon into Monday night. If a storm can develop, wind gusts to around 50 mph will be possible. The better chances will be south of Highway 18.

- After seasonal temperatures into Monday, cooler than normal temperatures return midweek. Areas of early morning frost or near- freezing temperatures are possible by early Wednesday and Thursday.

DISCUSSION

Issued at 152 PM CDT Sun May 3 2026

Northwest winds will gradually diminish through the afternoon and turn more westerly this evening. Some very localized elevated fire weather conditions are expected where some of the warm season grasses remain fairly cured.

A broad trough to the north will settle south tonight into Monday. This will initially turn winds to the west and southwest tonight, before turning north on Monday morning. For the most part this will be a dry front, but some mid level moisture and very weak instability may allow for a light shower. Otherwise, in the afternoon in mainly northwest IA some weak instability could allow for an isolated shower or thunderstorm, with no severe weather expected. As with last nights showers some gusty winds will be possible with any showers.

The main changes with this incoming front will be cooler, below normal temperatures. Highs on Tuesday and Wednesday will be in the 50s, with morning lows Tuesday, Wednesday and Thursday mostly in the 30s. Areas north of I-90 could see some frost and freezing temperatures all 3 mornings while areas near and south of I-90 will see the better chances for frost and freezing temperatures on Wednesday and Thursday mornings.

Otherwise, northwest flow aloft will be in place Wednesday into the next weekend which suggests that even if we can get a few waves to move through the area, moisture and instability will be a bit lacking. Temperatures Thursday into the weekend do climb back to around or a bit above normal with highs mostly in the mid 60s to lower 70s. Very little consistency in the model output for these weak waves so confidence on any isolated to scattered showers is pretty low.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 646 PM CDT Sun May 3 2026

VFR conditions expected through the period. Winds will begin turning southwesterly through the evening ahead of a cold frontal passage. Once this cold front moves through the area over the course of Monday morning, winds will turn northwesterly and increase. Wind gusts will peak around 30 to locally 35 kts Monday afternoon, strongest west of I-29. A few spotty showers/sprinkles will be possible mainly Monday afternoon and evening. Lastly, LLWS concerns will develop briefly near and north of I-90 as the nocturnal low level jet begins to kick in tonight.

FSD WATCHES/WARNINGS/ADVISORIES

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