A low pressure system will be dropping southeast out of central Canada Saturday night, and be over Minnesota on Sunday. It will bring a few clouds beginning late Saturday night through Sunday morning. There will still be a fair amount of sunshine Sunday morning, and with winds from the south, highs will be pushing the upper 70s. It looks like this low pressure system will spark quite a bit of shower and thunderstorm activity across Minnesota and the western half of Wisconsin. The question is how far east the storms will reach. I'm seeing mixed signals on this, and the entire day could very well stay dry. But I will have a 40% chance of showers and thunderstorms late in the day to account for the possibility of them coming farther east. I think that the only race that will have a threat of rain will be the TC/TCA/TCB race that begins at 4:15 local time.