Add this metric to your list of recession indicators: the year-on-year change in civilian unemployed - 15 weeks and over. Whenever this measure exceeds 0% for a sustained period there has been a recession. This pattern can be seen in the figure below, where NBER-dated recessions are in gray bars (click on figure to enlarge):
The consistency of this pattern is remarkable. Thanks to Robin G. Brown, one of my students, for pointing this relationship out to me.