Harvey's rainfall legacy in central Louisiana.
Harvey is heading into the Ohio Valley as a post-tropical cyclone, but the rainfall dumped on portions of central Louisiana has led to one of the wettest, if not the wettest, Augusts on record.
One of the characteristics of Harvey's rainfall pattern is variability. It is well-known that rain varies significantly over small distances. This can be especially true in tropical systems. Although everyone received a lot of rain, some territory over northeastern Louisiana got the least. One reason for this behavior is dry air that wrapped into the east side of Harvey's circulation and cut down the totals over that area.
From a historical perspective, the huge total of 21.80 inches west of DeRidder may be a 200-year event. Other amounts fit the 100-year profile.