The Atlantic hurricane season officially begins in just one month, but there is a system worth watching for at least some slight development this weekend. A weak surface low pressure system is expected to develop southeast of the Bahamas late this week, and there is a low chance that it could take on some subtropical or tropical characteristics this weekend. This has been a hotspot for May tropical cyclones in recent years. Six tropical cyclones have formed in the Atlantic in the month of May since 2007.

Model support for this system is limited. The operational 12Z GFS and ECMWF model runs predict a weak surface low will develop, but not a tropical or subtropical cyclone. About 20-30% of the 12Z GEFS ensemble members predicted weak development. The UKMET model does not predict any development will occur. I give this system only a 10% chance of development, due to the limited model support, expected strong wind shear and marginal sea surface temperatures of around 26-27°C (78.8-80.6°F).

The National Hurricane Center (NHC) has not included this system on their Tropical Weather Outlook. During the off-season, NHC will occasionally issue Special Tropical Weather Outlooks if conditions warrant. It is likely that high wind shear will limit significant development of this system.

For more on the history of May tropical cyclones in the Atlantic, check out this article from May 2017. In the unlikely scenario that this system becomes a tropical or subtropical storm, it would be named Alberto.

I will be back with an update on this system tomorrow. It appears as if heavy rain in the Bahamas and Greater Antilles will be the main threat.