Four systems to watch in hyper-active Atlantic hurricane season

The U.S. may have already seen three hurricane landfalls, including that of Category 4 Laura, but the historical peak of Atlantic hurricane season hasn’t even arrived yet. The tropics continue to remain bustling with activity, with the National Hurricane Center monitoring four additional systems. Two look to develop in the short term, but with limited impacts to the U.S. The fate of the other two is more uncertain.

The Atlantic has featured a typical season’s worth of storm to date in 2020, the ocean basin as a whole cranking out 55 percent more energy in tropical storms and hurricanes than typical by late August. The hyperactive season has also delivered the earliest C, E, F, G, H, I, J, K, L, and

M named storms on record, even remaining ahead of the record-setting pace in 2005.

The four tropical systems under investigation are at various stages of development. One of them is poised to develop off the U.S. East Coast and head out to sea, while another could soon fight for a name in the western Caribbean. Meanwhile, two others — located between the Lesser Antilles and Africa in the Atlantic’s “Main Development Region,” or MDR — are less organized, but could develop in the coming days.

On Monday, the National Hurricane Center scheduled a Hurricane Hunters aircraft to investigate a system about 150 miles south-southeast of Wilmington, N.C. The Center estimates the system has about a 70% chance of developing into a tropical depression or receiving a name as a storm. The next name on the list is Nana.

The system was visible on the Wilmington radar as a spattering of showers well offshore Monday morning, but the system already appeared to have a well-defined center. Satellite imagery also suggested it captured a lot of convection, or shower and thunderstorm activity, to the east of the center and outside of radar range.

In the coming days, the initially innocuous tropical system, dubbed Invest 90L by the Hurricane Center (“Invest” refers to an area of disturbed weather under investigation), is likely to slowly develop as it churns north-northeast, remaining entirely offshore. It will eventually recurve to the northeast and ultimately the east, passing harmlessly between Cape Cod and Bermuda as it pulls away into the open North Atlantic.

Since the system will be outrunning the warm waters of the tropics, it probably won’t intensify into anything more than a tropical or subtropical storm, its only impacts perhaps being an increased risk of rip currents in coastal beaches of the Mid-Atlantic.

Another disturbance, known as Invest 99L, is cruising quickly through the Caribbean as it heads westward. The system already appears quite organized, though conditions are expected to become more conducive for development today. Because the system is moving so quickly right now, at close to 20 mph, it is in a sense struggling to keep up with itself.

The system should pass south of Jamaica late Monday or early today, but heavy rainfall is possible if showers and thunderstorms develop on the system’s northern fringe.

“Cloudy [weather] with periods of showers and thunderstorms across most parishes” is likely today and Wednesday, wrote the Meteorological Service of Jamaica.

Invest 99L has been assigned an 80% chance of development by the National Hurricane Center, with the system on a crash-course with Honduras, Belize, coastal Guatemala and the Yucatan Peninsula. The system should make landfall, likely as a tropical depression or storm, around Wednesday. Heavy rainfall, gusty winds, and perhaps some inland flooding would be possible.

The Atlantic’s Main Development Region, an invisible box within which the majority of long-lived, powerful Atlantic

hurricanes develop, was eerily quiet on Monday morning. The National Hurricane Center slashed the odds of the first of two disturbances developing to just 10 percent, while the second cluster of shower and thunderstorm activity, currently between Senegal and Mali, had a 30% chance.

The lead disturbance is likely to fizzle, but the trailing one could perk up later in the week. The Center forecasts “gradual development of this system ... through the end of the week” is possible, with more clarity in the forecast likely once the system moves over water.

There is no immediate threat to the United States from any of these three tropical cyclones, but if the wave currently over Africa develops, it could track west on a trajectory that could potentially impact land.