User blog comment:CycloneRyne94/How?/@comment-26971007-20170712041746

The reason why this "de-materialized" was the passage of a convectively suppressed Kelvin Wave. The GFS did not correctly predict this and instead predicted that there would be enough upward motion to allow development. The GFS also severely underestimated the dry air and wind shear over the Atlantic. Now I think we probably won't get Don until late July or early August, but I still think that the season should be at least slightly above average since El Niño has not materialized.