Strong to severe thunderstorms are still possible through the evening hours tonight. A stationary boundary continues to sit across the entire state and will be one of the driving forces for thunderstorm activity tonight. As this boundary slowly makes its way out of the area thunderstorms should follow.
Current guidance has storm activity picking up around 9-11 PM tonight. A large cluster of storms will move across the viewing area and threats will range from strong winds, heavy rain, and an isolated tornado can’t be ruled out just yet.
I do think the main issue tonight will be heavy rain creating “Flash Flooding” concerns. A “Flash Flood Watch” has been issued by the National Weather Service for all of the KTTC viewing area from 7 PM Wed until 7 AM Thu. Rainfall amounts could reach near 2-4″ inches in some isolated areas if training thunderstorms start to develop.
Timing for severe weather still seems to be late tonight. Current model guidance suggests the cluster of storms moving through Rochester by 11 PM – 12 AM. I think we start to see thunderstorm develop to the west of the Twin Cities by 9-10 PM and those storms will impact our viewing area by 10:30-11PM.
Light showers will linger into Thursday morning but shouldn’t impact the daytime hours. Heat becomes the main concern moving forward for both Thursday and Friday. A “Heat Advisory” has been issued for all of our Minnesota counties and there is still an “Excessive Heat Watch” for several of our Iowa counties. The advisory and watch run through Friday evening.