re: Hurricane Season - Random Posts Thread - Gulf Record 1,058 Days

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It seems, the last few years, that there have been waves that should have formed into storms but could never get really organized because they were moving so fast. The storm last week seemed to have the same problem. Will this continue?

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A portion of the fast motion can be attributed to many of the waves moving across the Atlantic having poor structure. A vertically stacked wave with deep convection is going to move slower and have better prospects for development. There has been more dry stable air across the Atlantic MDR the past few seasons making it hard for waves coming off Africa to develop and that trend is continuing this season:



and if this MJO forecast holds, then that trend will likely continue as we move towards September and peak season:



There has been a lot of research over the past few years on this topic. One of the things that seems likely to me is that warmer global SSTs are altering the large scale atmospheric circulations:



The expansion of the Hadley Cell appears to be driving a portion of the changes in the Atlantic MDR that might be making it harder for systems to form in the MDR.