The Fond du Lac County Sheriff’s Office is warning residents that ice conditions are sketchy on Lake Winnebago with the sturgeon spearing season set to open this weekend. Sheriff’s captain Bill Tadych says last week’s record cold snap helped, but the warm weather Sunday and Monday caused some melting. “Both the east shore and west shore, the reports that I got, was that cold snap added about 6-7 inches of good ice,” Tadych, told WFDL news. But Tadych says the warm weather Sunday and Monday deteriorated the ice along the shoreline. Tadych says people participating in the Sturgeon Spectacular festivities need to be careful if venturing out onto the lake.