Nothing says spring in Boston like a week where bright shamrocks, the spring equinox, and a little snow all coexist on the agenda. Whether you wish to celebrate your Irish heritage, or simply dig festive processions, check out Boston’s St. Patrick’s Day parade this Sunday starting at 1pm at the Broadway T stop in South Boston. Abington and Scituate also will host parades this Sunday, as will Holyoke and Manchester, NH on the 30th. And if you happen to be cross continental, Dublin’s parade is, of course, on Monday.