• Bryan Norcross

Eastern Atlantic Disturbance has a chance to develop in a few days

A robust Tropical Disturbance in the far eastern Atlantic will have a chance to develop into a tropical depression or tropical storm when it reaches the waters east of the southernmost Caribbean islands in a few days. The disturbance is accompanied by an unusually large slug of moisture for June, which increases its possibility of organizing.

In addition, it is located far enough south that it is avoiding the dry air and hostile upper winds that cover much of the tropical Atlantic. On the other hand, systems that form south of 10 degrees north latitude have more trouble organizing a circulation because the spinning of the earth doesn’t help them as much.

If you think about it, a point on the equator is flying through space at high speed because it has to go all the way around the fattest part of the earth every day. But a point off the East Coast of the U.S. farther north, for example, doesn’t move as fast because the distance around isn’t as far since it’s farther up the ball. It’s that difference in speed at different latitudes that generates the spin in weather systems. Systems at low latitudes don't have as much speed difference north to south.

A French mathematician and scientist, Gaspard-Gustave de Coriolis, figured this phenomenon out in the 1830s. We call it the Coriolis Effect.

The consensus of this afternoon’s computer forecast models is that some development of the system might take place before the disturbance reaches the southern Caribbean islands. The National Hurricane Center is giving it a slight chance.

High pressure will keep the disturbance from moving very far north for now. Beyond five days, most of the long-range models hold it well south, but that would likely be dependent on how strong the system can get, if it strengthens at all.

This disturbance is positioned similarly to the one that eventually became Hurricane Elsa last year, which impacted the Caribbean islands and eventually tracked offshore of the west coast of Florida in the Gulf of Mexico. This one is even farther south, however, making it quite unusual for this time of the season.

For now, it bears watching. It has some things going for it but has a couple of strikes against it as well.