The first low in Texas will continue to draw moisture northward this afternoon with rain likely developing around 3pm and continuing into the overnight. Precipitation type will be all rain for this evening because temperatures throughout the atmosphere will be warm enough to support it. Once the low moves into Michigan by Friday it will weaken and become 'caught up' in the jetstream leaving Friday evening and Saturday afternoon fairly dry. The second system will pull a cold front through by Saturday afternoon with colder air moving in by Saturday night. The BIG question with the second system is just how far east the front will be by Sunday morning. It looks like low pressure will develop on the southern end of the cold front and pull north as the front moves through northern Illinois and southern Wisconsin. If the front stalls near Chicago snow may fall for the first half of Sunday. If the front is far enough east then all the precipitation will stay east as well. Last night it looked like there was the possibility of accumulating snow by Sunday but models this morning have backed off just a bit on that idea. Of bigger concern may the transition period late Saturday night. Temperatures a few thousand feet above the surface will have dropped below freezing by Saturday night but at the surface temperatures may be just near or slightly above freezing. This could cause any rain that would be falling to transition to sleet or freezing rain before switching to snow. Something to keep in mind if you'll be out late Saturday or early Sunday.