(Accu Weather) – It’s just one week into the 2021 Atlantic hurricane season, and meteorologists are watching the tropics with a particularly close eye on the waters surrounding Central America. AccuWeather forecasters say the potential exists for development of a tropical depression or storm — one that they have been scrutinizing for the past week — and the chances will grow in mid- to late June. Additional disturbances could take shape in other parts of the basin as well.
An uptick in showers and thunderstorms over Central America, southern Mexico and some of the islands in the western Caribbean is forecast late this week and this weekend.
Strong wind shear will likely to remain an inhibiting factor for tropical development through the middle of this week over the western Caribbean and Gulf of Mexico; this has been the case thus far this season. However, that tropical suppression factor may be about to change.
Wind shear is the increase in speed or change in direction of breezes at different layers of the atmosphere above the sea surface or across the sea surface in the horizontal. When wind shear is strong, it tends to limit tropical storm development or cause an established tropical system to weaken. When wind shear is low or diminishes, the door can open for tropical systems to develop and strengthen more readily, especially when other favorable conditions come into play.
“Wind shear is expected to diminish over the western Caribbean Sea late this weekend to next week, which may allow the increased thunderstorm activity to gradually organize and form an area of low pressure,” AccuWeather Senior Meteorologist Rob Miller said.
“Provided wind shear remains low, this low pressure area may slowly develop into an organized tropical system in the northwestern Caribbean Sea or southwestern Gulf of Mexico this weekend to next week,” Miller continued.
Cool water and dry air also tend to inhibit tropical development. Waters are sufficiently warm in the region to support tropical development and dry air in place from the start of this week is likely to be eroded from multiple angles by this weekend.
There is potential for a tropical storm to develop in the northwestern Caribbean, according to AccuWeather Senior Meteorologist Joe Lundberg. He added that a “track into the Gulf of Mexico is a viable concern for the third week of June.” If a storm were to develop, it would be the second named storm of the 2021 Atlantic hurricane season. The next named tropical storm will be given the name Bill.
“Whether or not there is tropical development over the coastal waters of the Eastern Pacific, flooding rainfall and strong winds can impact parts of El Salvador, southern Guatemala and southeast Mexico this weekend into early next week,” Miller said.
It was just about a week earlier in the season last year that the formation of the Central American Gyre contributed to the formation of Tropical Storm Amanda along the coast of El Salvador over the Eastern Pacific on May 31, 2020.
Amanda moved ashore later on May 31, 2020, and then dissipated over southern Guatemala. However, part of the moisture and wind field left over from Amanda gave birth to Tropical Storm Cristobal along the coast of Mexico’s Yucatan Peninsula in the southwestern Gulf of Mexico, which is considered to be in the Atlantic basin.