August is well and truly hurricane season. After Hurricane Grace and Tropical Storm Henri made landfall over the past weekend, some might’ve expected a respite from the foul weather. Unfortunately for us, however, things are just getting started in the Atlantic.
While no storms have yet been named, satellite imagery clearly shows the beginnings of three distinct clusters of thunderstorms in the Atlantic.
Hurricanes on the Horizon?
Out of all the potential storms, the tropical feature located in the southern Caribbean is arguably the most concerning due to its proximity to land. Thankfully, the tropical feature is showing few signs of strong, organized convection, so it might be a few days before things really start to rock and roll.
The two tropical features located further toward the eastern part of the Atlantic can’t be ignored, of course, and there is a chance of further development of each feature in the coming days.
However, these two features have some major obstacles in their way before they can become fully-fledged tropical cyclones. One of the most notable issues impeding the development of these storms is the large amount of Saharan dust that’s tracking its way across the Atlantic.
Saharan Dust & Hurricanes
If you were in Florida over the last few days, you may have been treated to some spectacular sunsets. These sunsets are thanks to none other than the Saharan Air Layer and the large amount of dust that occasionally makes its way to the western Atlantic.
Well, dusty air that gets blown off of the west coast of Africa often ends up getting undercut by a layer of moist low-level air from the Atlantic Ocean. This causes an elevated parcel known as the Saharan Air Layer (SAL), which is known to trek across the Atlantic to the Americas.
We can actually see this dust on satellite imagery, like the above image. There’s a whole heck of a lot of dust gathered around the eastern edge of one of the tropical features in the middle of the North Atlantic.
As a general rule, this dusty air is doom for a fledgling tropical storm system because it is very, very dry, which could cause dry air entrainment and stop strong convection in its tracks.
Additionally, the Saharan Air Layer is usually accompanied by strong wind shear, which is catastrophic for a tropical storm. While hurricanes pack heavy winds, they actually require low wind shear conditions to form.
Recent deep layer shear measurements suggest that the environment is currently unfavorable around this tropical feature for the formation of a tropical cyclone.
Too Tropical for a Tropical Cyclone?
So far, we’ve focused mostly on the northwesternmost tropical feature that’s brewing in the Atlantic. However, we ought to pay some attention to the feature in the southeast.
While this feature seems to have escaped the brunt of the Saharan dust coming off of the African continent, it doesn’t quite seem to have a high chance of developing into a full-fledged storm and then making its way to the Americas.
Of course, this could still happen, but this feature is located very close to the equator. While tropical cyclones do generally develop in the tropics, the lack of Coriolis force at the equator is problematic for storm development.
Nevertheless, we ought to keep our eyes on this storm and see what develops. If it does develop, it’ll probably be quite a few days before we see it on this side of the Atlantic, given how far it has to travel.
But, if this feature can overcome the perils of its southerly location and if it can make its way around the strong Bermuda high, we just might see it in the US.