At a Glance

Dorian was a powerful hurricane that left cooler water behind near the Bahamas.Cooler water can inhibit tropical cyclone formation.However, there is still plenty of heat in the ocean in that region to support tropical development.

Dorian stalled for two days as a powerful hurricane over the northwestern Bahamas, bringing cooler water from deeper in the ocean up to the surface as it spun over the same area for so long.

Water temperatures are now slightly below average near the Bahamas in Dorian's wake, but even though sea surface temperatures are an important ingredient for tropical cyclone formation, this will likely not deter from developing.

(MORE: Hurricane Dorian Recap)

The process of cooler ocean water rising to the surface is called upwelling and it's caused by strong winds from tropical systems stirring up waters along their paths. This effect is more pronounced when a tropical cyclone remains over the same area for several days like Dorian.

Areas in blue indicate water temperatures cooler than average, while areas in yellow are warmer than average.

Although sea surface temperatures are now cooler than there were before Dorian moved through, there is still enough to sustain tropical cyclone development.

Ocean heat content is the heat energy that the ocean absorbs, mostly from sunlight. Tropical cyclones feed on this latent heatwhich provides the energy for the system to develop and intensify.

Water temperatures are generally in the 80s near the Bahamas and off the Southeast coast of the U.S., which is warm enough to fuel a tropical cyclone. Sea surface temperatures of at least 80 degrees are needed for tropical cyclone formation.

is expected to track through portions of the Bahamas, near Dorian's path, into this weekend.

Conditions are expected to be favorable for development, including warm water temperatures, and it will likely become Tropical Storm Humberto near the Bahamas and then possibly a hurricane off the Southeast coast.

The upwelling process is not unusual.

For example, in 2018, tracked off the East Coast and remained over the same area for an extended period of time, to the surface.

did the same thing. Before the storm, water temperatures in the western Gulf of Mexico were 1.5 to 4 degrees Celsius warmer than average, but as it churned in the Gulf waters cooled near the coast.

Sea surface temperatures cooled near the Texas coast due to Hurricane Harvey in August 2017.

(NASA)

Sometimes, a tropical system lingers over the area long enough that the cooler water can even cause itself to weaken.