Tropical storm Arthur stirs fear of hyperactive hurricane season

As Tropical Storm Arthur moved up out to sea, forecasters worried that it is just the first domino to fall in a hurricane season that has the potential to mirror the worst ever.

Arthur became the first named storm of 2020 when it reached tropical storm status over the weekend.

The storm moved out to sea Monday after dumping heavy rain on North Carolina. Two cities, Newport and Havelock, recorded more than 4 inches of rain

This is the sixth year in a row that a named storm has preceded the formal June 1 start of the hurricane season, said meteorologist Jim Foerster. While early storms boost a season's overall numbers, they don't indicate the ferocity of what will happen in the deep Atlantic during the height of the season.

This year, scientists see ominous clues with conditions in place similar to 2005, when a record 28 storms moved across the Atlantic, including Hurricane Katrina, which devastated New Orleans, killing 1,800.

"All the puzzle pieces are in place, no matter how I slice and dice it," Jim Rouiller, the lead meteorologist at the Energy Weather Group, said. "It gives me higher than normal confidence this year will mimic a hyperactive hurricane season, and that is what 2005 was."

Exceptionally warm waters in the Atlantic have the potential to rev up the 2020 hurricane season. While 2020 might not produce as many storms, the summer and fall could have the feel of that record-breaking year, Rouiller said.

Two other indicators scientists are keeping a close watch on both carry the potential to rev up storms.

The first is an eastward-moving disturbance of clouds, rainfall, winds and pressure known as the Madden-Julian Oscillation, according to Rouiller. This year, the oscillation is likely to send a number of strong pulses of atmospheric energy across the Atlantic during the heart of hurricane season, unleashing a cluster of storms, he said.

The second is the buildup of warm water in a broad stretch between Brazil and Africa, according to Ryan Truchelut of Weather Tiger, a commercial forecaster in Tallahassee, Fla.

The water in that band could well migrate northward in the next few months, Truchelut said, adding more heat into the area between the Caribbean and Cabo Verde where some of history's most destructive storms have formed.

The early start of the season with Tropical Storm Arthur is also concerning. The start dates for hurricane season are based on long-term averages, but climate change is allowing conditions ripe for tropical storms to arrive earlier — and stay later — in the calendar year.