The Atlantic and eastern Pacific oceans may soon spawn tropical development. AccuWeather meteorologists will continue to monitor several areas for tropical activity, including the central Atlantic to near Central America and the East Coast of the United States.
If an organized system were to take place in the East Pacific, it would be the first named storm of the season, which began on May 15. Meanwhile, Tropical Storm Arlene and an unnamed subtropical storm are already in the books in the Atlantic, with the latter having formed well ahead of the official hurricane season, which began on June 1.
Read on for a breakdown of the potential tropical threats that may emerge, starting with what may be the most notable zone that forecasters are keeping close tabs on — and an unusual zone for early on in the season.
Typically, the backbone of the Atlantic hurricane season occurs when tropical storms form from tropical waves that emerge from Africa and track westward across the basin. This kind of development usually takes place during the heart of the season from mid-August through September. Often, these features remain too weak and/or atmospheric conditions are too hostile for organized systems to brew earlier in the season.
This season, conditions seem to be different, AccuWeather meteorologists say.
The tropical wave activity has been rather robust for so early in the season this year and likely has a lot to do with the lack of dust originating from the Sahara Desert. That has allowed more of the sun’s energy to heat the ocean water. Sea surface temperatures from Africa through the Caribbean and across much of the Gulf are 5-10 degrees Fahrenheit above the historical averages and range from the upper 70s along the northeast coast of Africa to the mid-80s in the western Atlantic and Caribbean and are near record levels over the Equatorial Atlantic.
AccuWeather meteorologists will be monitoring a tropical wave that will travel westward from Africa next week for potential development.
“While it is rare to get a storm to develop over the south-central Atlantic in June, it is not completely unheard of,” AccuWeather Tropical Meteorologist Alex DaSilva said. There have been only a half-dozen or fewer tropical systems to develop in this zone over the past 25 years in June.
At this time of the season, a tropical wave would need to be robust and encounter a favorable environment, including an atmosphere with a decent amount of moisture and weak wind shear, or winds that do not vary much with altitude, in order to strengthen enough to be named, DaSilva explained.
“It looks like the road ahead for this tropical wave will be mostly favorable for development, especially in the longer term as it nears the Caribbean,” DaSilva said.
“Some dry air may inhibit development in the short term, and it appears this system may have to remain south of the strongest wind shear to flourish,” AccuWeather Chief On-Air Meteorologist Bernie Rayno said. Wind shear is forecast to drop off as the system drifts west — a factor that could further aid its organization.
The tropical wave being closely monitored will not approach the Leeward and Windward islands of the eastern Caribbean until later next week.
As the broad area of low pressure near Central America slowly spins and grabs moisture, pockets of thunderstorms will continue to erupt in its vicinity. Before Thursday, most of the activity was located over land and the eastern Pacific.
However, an uptick in thunderstorms over the western Caribbean was observed on Thursday, which is a sign that the Central America Gyre’s influence was expanding.
The western Caribbean may show some spark early next week with some data suggesting a northward-moving cluster of rain and thunderstorms.
Meanwhile, there is the potential for a weak tropical system or two to form over the eastern Pacific.
The first name on the list for the East Pacific hurricane season is Adrian. Any feature that develops would tend to move westward and away from land, but shipping interests approaching or departing the busy Panama Canal waterway may want to monitor the situation.
Much like tropical waves that emerge from Africa and move westward over the Atlantic, occasionally disturbances associated with severe thunderstorm complexes from the U.S. can cause trouble as they drift off the Gulf or Atlantic coasts. AccuWeather has been warning of severe thunderstorm complexes that may even evolve into damaging derechos through next week across the central and southern U.S.
Since wind shear is likely to remain fairly strong along the Gulf and Atlantic coasts into the end of the month, these systems may struggle to spawn a tropical system. However, once in a while, a thunderstorm complex can defy the odds, and wind shear may drop off long enough to allow a system to evolve into a tropical depression or storm.
Water temperatures are generally close to the critical threshold of 80 degrees in these coastal areas. Still, there are even warmer pockets, including warm water associated with the Gulf Stream along the Atlantic coast and the Caribbean current that extends into the Gulf of Mexico.
Produced in association with AccuWeather
Edited by Maham Javaid and Virginia Van Zandt