Plan on using alternate routes if you need to get downtown this Sunday.  Aurora Avenue will be closed on March 14 from N. 39th Street to the Western Avenue off-ramp for the Henry Weinhard’s St. Patrick’s Day Dash.  14,600 participants are expected to take part in the event.  Roads will be closed from 7:30 a.m. to 11:30 a.m.  The Alaskan Way Viaduct will also be closed during that time.