Experts have already predicted another active hurricane season, coming on the heels of the busiest Atlantic hurricane season on record. Thirty named storms spun up last year, including 14 hurricanes, seven of which reached major hurricane strength.
This season to date has already featured one named storm — Ana — that attained low-end tropical storm status and danced briefly in the open Atlantic from May 22 to 24.
Depression off Carolinas likely to soon be named Bill
At 11 a.m. Monday, the National Hurricane Center in Miami declared a system off the Outer Banks of North Carolina a tropical depression, meaning it had achieved a closed circulation and winds of 35 mph. Tropical depressions are the precursors to tropical storms.
On satellite imagery, it exhibited a well-defined mass of downpours and thunderclouds whirling about a common center, with the “overshooting tops” of tall storms visible near the middle. The system was drifting northeast at 21 mph.
It existed in an environment with ocean water temperatures marginally supportive for intensification, with minimal wind shear — a change in wind speed and/or direction with height — to inhibit storm organization. It may have consolidated and intensified more quickly than originally forecast after being influenced by a lobe of spin, or vorticity, left over from dying storms that passed through the southern Appalachians on Sunday night.
It’s predicted to become a tropical storm by Monday evening, meaning winds will surpass a 39-mph threshold, and earn the name “Bill.” Despite being named, its impact on the United States will remain negligible as it draws into the open Atlantic, and the storm will probably drift out to sea before losing tropical characteristics and bringing gusty winds to Newfoundland on Wednesday.
Meanwhile, two additional tropical threats also bear watching, including one that could affect the U.S. Gulf Coast.
Gulf of Mexico system
As of midday Monday, that one was located broadly over parts of Central America near and south of the Yucatán Peninsula. That’s where a disorganized clustering of downpours and cloud cover was slowly orbiting around a circulation known as the Central American Gyre. That broad area of diffuse spin and enhanced thunderstorm activity will drift north in coming days, and it’s possible a more concentrated, focused area of spin could develop within it and become a tropical storm.
It was unclear where the center of the disturbance was early Monday afternoon, but the National Hurricane Center continues to highlight the system as having a 60 percent chance of development in the Bay of Campeche or western Gulf of Mexico in the next five days. By late in the workweek, it will probably fully emerge over warm Gulf waters, allowing it to intensify.
The most likely scenario is for the gyre to crank out a storm late in the week or toward the weekend, which, assuming the system off the Carolinas is named Bill, would be designated “Claudette.” From there, the storm would drift northward, affecting the northern Gulf of Mexico somewhere between East Texas and the Florida Panhandle.
This far out, it’s impossible to cast predictions regarding the intensity of a storm that has yet to develop, but its prospects are probably capped at being a high-end tropical storm or low-end hurricane. That means wind wouldn’t be the primary threat, but rather very heavy rainfall and coastal flooding.
A general four to six inches with localized amounts topping eight inches are likely where the system comes ashore in the United States late week regardless of whether it has a name. That part of the country has already seen serious flooding over the past several months, with some spots picking up three feet of rain or more since the start of April. Flash-flood emergencies were issued in May in Baton Rouge and Lake Charles, La.; residents in Louisiana and Mississippi in particular should monitor the progress of the system.
The overall weather pattern suggests anything that moves ashore would be primed to continue dropping heavy rainfall inland across much of the Deep South and Southeast.
Looking ahead, the meteorologists are also keeping tabs on a strong tropical wave in the eastern Atlantic that just exited the coast of Africa. In the short term, development is unlikely thanks to dry air aloft and strong high-altitude winds hostile for storm growth.