(My week numbers have been off, so this is the 2nd “Week 50” … My apologies!) Welcome to the latest in the Races on our Radar series, where we report on cool and/or low-cost races, group runs, price and registration deadlines, and other things we think you should know about it. We would like to you hear from you, too. If you’re in the know on a race that you think others need to check…