Forecasters say rain and melting snow could cause flooding and ice jams at any time.  The National Weather Service in Romeoville says rivers and streams are expected to rise in the region after the rain on Friday.  The rain comes as northern Illinois is already covered by as much as 14 inches of snowpack.  That’s melting as temperatures finally climb above freezing after fierce artic weather sent temperatures to record lows last week.  Meteorologists say residents who live near low-lying flood-prone areas should be alert for rising water through the week.