The Oh-So-Quiet Atlantic Basin
The Atlantic Hurricane Season starts off on June 1st and lasts 6 months until the end of November.
The peak of the season occurs in mid September on the 10th and we usually notice activity picking up through July, into August & September with several storms forming from tropical waves or a lingering area of disturbed weather (such as the tail end of a cold front). But this year, things are different. The Atlantic Ocean and Caribbean Sea have been relatively quiet with only a few depressions and storms forming so far this season.
There have only been 7 depressions that have become strong enough to become named tropical systems. The latest storm to form was Tropical Depression #8 which formed in the Bay of Campeche in the southern end of the Gulf of Mexico. It traveled westward, into Mexico, where it weakened then dissipated. None of the named storms, from Andrea to Gabrielle, became strong and organized enough to become hurricanes.
In the peak month of September, Cape Verde type storms form off of tropical waves that come off of the African mainland and travel across the wide-open spaces of the Atlantic. Closer to the Americas and the Caribbean, the conditions are where its very favorable for tropical development of a system or wave that traveled through there. If the ocean temps are warm enough (80-90°+) and the wind sheer aloft is light to none, storms should develop nicely.
There has been an unusual high amount of dust this year coming off of northern Africa. It is traveling across great distances in the Atlantic Ocean and this has stiffed the potential growth from any tropical wave to grow and strengthen. The dust and sand makes the air dry and one of the factors that goes into development of these disturbances is high levels of moisture in the lower levels of the atmosphere.
Looking back at the climatology of the Atlantic Basin, at this point in the season, we should have seen (on average) the 6th named system, the 3rd hurricane, and the first or second major hurricane formed. We have gone up to 7 named systems, so we are okay there, but the other to categories is where we have seen no development.
The lackluster strength of the tropical storms (where they formed and faded away shortly thereafter) and no hurricanes has been very unusual this season. So much so that we have been trending towards record-breaking territory. There is a streak out there has not been broken or been challenged in over a decade pertaining to when the latest “first hurricane” of the season would form. The last time we saw a system forming and becoming a hurricane this late was back around the climatological peak of the 2002 season when Gustav formed on September 11th. That year there were only four hurricanes for the season. As of today, September 7th, we would rank 4th on the list below. With the 11th just around the corner and no waves right now likely to become a hurricane, that record could be broken.
Typically the first hurricane forms around the middle of August with around this of the season, a tropical storm becoming strong enough to be the 3rd hurricane.
In the beginning of September, we should on average see a major hurricane develop and come around. Every now and then, those hurricanes formed and threaten the US mainland, but in the past, have weakened before they made landfall. In terms of the last time the US has been impacted by a major hurricane making a landfall, that is a streak that continues to go on and on, ever since 2005.
That year was the year that rewrote the books on tropical systems and Hurricane Wilma is certainly a storm worthy of its own chapter. That system went from being a tropical storm to being a category 5 hurricane in a matter of roughly 48 hours as it went through extreme intensification. It would eventually travel to the northeast from the Yucatan Peninsula, towards Florida, where it made landfall as a category 3 storm. Ever since then, there hasn’t been a single major hurricane to make landfall on the US. That streak is 2,874 days and counting and that frame of time, from then to now, is the longest period that we have gone without a major hurricane landfall in 150 years.
But just because the season has been a quiet one, doesn’t mean we should put our guard down. There are still several weeks to go before the season is over, and as Autumn progresses, we could potentially find these systems forming, and closer to home.
Meteorologist Addison Green – Twitter: @agreenWNTV