A major storm could hit Parry Sound and Muskoka as early as this afternoon.  Environment Canada continues to track an Alberta clipper and a Texas Low and expect the two systems to merge over the Great Lakes and become stronger.  The storm system will bring rising temperatures with mixed precipitation and strong winds.  Meteorologists say precipitation is expected to start mostly as rain east of Lake Huron this afternoon then spread east, hitting colder air and likely beginning as snow over Central Ontario later this afternoon.  A brief period of freezing rain or ice pellets is likely during the transition from snow to rain.  Total rainfall amounts could be in the 10 to 20 mm range by Friday night. Significant snow melt due to the rising temperatures will also be a concern.