Many storms little ACE
The 2020 Atlantic tropical cyclone season has been setting records ever since it started with the number of named tropical cyclones (those reaching tropical storm category with winds of 35 kts or more) it has produced. This is the up to date provisional list as of early today (12th of September), but I’m sure it won’t be long before it will be out of date when storms Sally and Teddy are added in the coming days.
The 12th of September is peak season statistically for tropical cyclones in the north Atlantic so having three or four active tropical cyclones is not at all unusual.
The thing is the 2020 season may be knocking out named tropical cyclones left, right and center, but the accumulated ACE so far is a least eleven points below the 1981-2010 LTA.
So what’s happening?
I reckon it could be because of a combination of one or more of the following reasons:-
(1) Conditions so far this season have not been conducive for many of the tropical depressions and storms that formed to further develop into full grown hurricanes.
(2) Maybe overzealous forecasters at the NHC who monitor the north Atlantic nudging some tropical depressions (Omar for instance) up a notch to 35 knots to make them a named tropical storm.
(3) Ever more enhanced monitoring from a host of sophisticated satellites, weather buoys, reconnaissance aircraft, and more detailed NWP models than ever before.
So why’s it happening?
I’ve never seen so much interest in a hurricane season like this one in Social media, maybe we have all had more free time because of COVID 19 to take an interest in them. 2020 was touted to be a busy season by many of the world’s Met Services, and so it has proved. But I think the main reason is the missing link between climate change and the number of hurricanes. Yes the SST in the tropical part of the north Atlantic are higher than average, and logic dictates that this should in itself aid the development of more frequent and intense tropical cyclones. Well this year has lived up to the frequent but not so much the intense uptill now. I wonder how long the season will run for and if the ACE index will start to rise.