Wednesday, April 17 2019: Showers and thunderstorms with occasional heavy rain over central and southern Minnesota today; and, more widely scattered over northern portions of the state. Morning east-southeast flow along a warm front helped to bring in particle pollutants from central/southern Wisc and northern Illinois. Some Yellow (moderate) readings at Rochester and Winona areas; but, will see improvement as showers/thunderstorms move through this afternoon and evening. Green (good) air quality statewide. The storm system will exit the state on Thursday with north-northwest winds ushering in cool air from Canada and continued Green (good) air quality conditions. Warming up on Friday as high pressure returns over the state and highs back into the 50s/60s. A nice warm up Saturday with possibly the warmest day of the year in parts of the state as temperatures reach the 70s especially southwest/southern Minnesota. There will be an uptick in ground-level ozone values; however, expect areas to be mostly Green (good) with occasional spikes into low Yellow (moderate) category. A cold front is slated to move through the area on Sunday bringing temperatures down 10-15 degrees from Saturday's highs.