textproduct: Sioux Falls

KEY MESSAGES

- Isolated thunderstorms will remain possible into early evening. While risks remain low, storms could produce quarter size hail and brief 60 mph gusts. Activity will quickly diminish by sunset.

- We'll be entering an extended period of hot and dry conditions through next week. Daily heat index values remain under 100 degrees in most areas, but the cumulative nature of the heat could lead to minor issues.

- Next risks for rain appear late in the forecast, focused on the Thursday and Friday time period.

DISCUSSION

Issued at 1253 PM CDT Fri Jul 10 2026

THIS AFTERNOON and NIGHT: Considerable mid-upper cloud cover from mid-lvl vorticity over eastern Nebraska continues to spreads across the CWA early this afternoon. High resolution guidance keeps this cloud cover spread over the eastern half of the Tri- State area into early evening. Depending on the thickness of this layer, temperatures could be hampered slightly. Further north, we continue to see a compact area of vorticity cross western and southwestern Minnesota with a bit of ACCAS nearby. While some sprinkles may develop with this ACCAS, deeper development remains less likely given weaker instability in the area.

While the high level clouds add some uncertainty, guidance has generally backed off on convective potential later this afternoon and evening. Likely due to a lack of any strong surface convergence and a bit of weak inhibition. I continue to see two areas to watch...one being with the ACCAS field near Watertown, but second along what might be where a weak surface convergence boundary develops by mid-late afternoon from DeSmet to Mitchell and Yankton. Instability in this area will run from 1500-2000 J/KG, but shear is very weak. This results in only pulse severe storms with quarters and very localized 60 mph winds.

Isolated convection may continue over central and west central Minnesota overnight, but further southwest we'll remain quiet with light winds. Some fog may pop up, but widespread dense fog isn't anticipated.

THIS WEEKEND: A quiet weekend is ahead as temperatures begin to slowly rise. Winds will turn to the south or southeast both Saturday and Sunday. High temperatures both days will reach into the upper 80s over MN/IA and into the middle to upper 90s west of I- 29. Heat index values remain below advisory criteria.

NEXT WEEK: A 600 DM ridge will center itself over the Northern Plains for most of next week. This pattern spells two thing...hot and dry. Each day will feature nearly the same identical setup, with a breezy southerly to southeasterly wind and plenty of sunshine. The resulting high temperatures reach the lower to middle 90s along and east of I-29, with temperatures soaring towards the 100 degree mark. ECE/GEFS probabilities show 40+ probabilities of >100 degree highs along the James River valley. The saving grace this week will be the persistent dry air aloft and breezy winds. The resultant mix down each afternoon will drop the dew points towards the 50s and lower 60s. This results in a lower heat index trend, with only isolated spots with a heat index value near 100. While we won't reach advisory criteria in most areas, the cumulative nature of the daily heat and slower fall in overnight lows could still lead to some health related issues.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1148 AM CDT Fri Jul 10 2026

VFR conditions expected into the evening and overnight hours. Widespread cirrus and scattered mid-lvl clouds continue this afternoon, with some diurnal based CU likely to develop this afternoon. There remains potential for isolated thunderstorms into early evening, but coverage far too low to indicate in current TAFs.

Light winds return overnight as skies clear. Clearing skies could lead to patchy fog by daybreak Saturday.

FSD WATCHES/WARNINGS/ADVISORIES

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