Latest on the Tropics: Is the Lull Coming to an End?

Alexis Thornton

4 months ago

The surge of tropical moisture that inundated Florida to start the week has been the only hint of activity in the Atlantic basin over the last few weeks. It has been mostly quiet in the Atlantic Ocean since Hurricane Beryl roared onto the shores of South Texas on July 8. However, forecasters with the National Hurricane Center (NHC) are warning that activity is likely to pick back up again in the weeks ahead. Here is what you need to know.

Change is on the Way in the Tropics

The NHC is predicting that it will remain tranquil across the Atlantic Basin through the end of July. This is a change from the start of the season that saw three named storms develop between the middle of June and early July.

The calm in the basin can be credited to what is known in scientific circles as the Saharan Air Layers (SAL). These masses of dusty air that originate in Africa's Sahara Desert work to mitigate the development of tropical weather.

However, while the SALs have been keeping a lid on tropical features in the Atlantic as of late, the latest computer models indicate that this environment will flip in the weeks ahead. These models are suggesting that a Madden-Julian Oscillation (MJO) could turn the tables in the basin and create an environment that is more supportive of tropical development.

The MJO is defined as an extensive area of enhanced clouds and moisture that moves to the east from the equator in the Indian Ocean, tracking around the world every 30 to 60 days. This area features various branches of rising and falling air. The zone becomes more supportive of storm formation when the air is rising. The rising air also breaks apart disruptive wind shear to further fuel the formation of the storms that serve as the base of tropical weather.

The latest data is signaling that the rising air associated with the MJO will make its way into the Atlantic Basin by the early part of August. The arrival of these conditions will likely bring an end to the calm period that has distinguished the Atlantic basin since Beryl dissipated.