4 May 2015
A tropical cyclone in early May is VERY rare in the Atlantic. Hurricane season does not start until June first, but there’s only about a 50% chance (on average) of seeing a June storm in the Atlantic Basin. That said, there are indications of a possible tropical cyclone developing east of Cuba in the next 36 hours, with several different numerical models indicating development. Some of the model guidance brings this system near the South Carolina coast in 72 hours but there is a high degree of uncertainty between the different models. As of now, I think we will likely see something develop, but it’s too soon to make any kind of forecast track.
Ocean temps. are well above normal over the Caribbean, and that will not hurt the development of this system. The image below shows temperature anomalies averaged over the past 4 days, and to any meteorologist the El Nino signature in the Pacific is glaringly obvious! More on that soon, but it’s looking like an El Nino is a good bet this summer and fall (perhaps a BIG one). If a significant El Nino does develop then it could cause the tropical storm season in the Atlantic to be rather quiet.
There was a named tropical storm (Alberto) in the Atlantic in 2012 (on May 22nd), and there were two unnamed storms in May 1887 as well. If we get a named storm this week, it may be the earliest named storm on record in the Atlantic. The record gets fuzzy back in the mid 1800’s, so there is some uncertainty over the earliest storm, and you also have to consider whether it’s tropical or subtropical as well. An accurate description of the difference is here.