The first named storm of the Atlantic hurricane season formed Thursday afternoon some 1,700 miles east of the U.S. East Coast.

Tropical Storm Arlene is just the second on record to form in April, the Weather Channel said. The only other tropical storm to form during the month was Ana in 2003. Hurricane season officially starts June 1.

Arlene's maximum sustained winds were near 45 mph, with higher gusts, the National Hurricane Center said. It was located about 815 miles west of the Azores. The system poses no threat to land and is forecast to dissipate Friday.

"I have to add one more surprise to my long hurricane forecasting career," hurricane center meteorologist Lixion Avila wrote in an online forecast discussion.

"Tropical storms in April are rare and Arlene is only the second one observed in this month," since the satellite era began in the early 1960s, he added. Before that time, such storms were practically impossible to detect.

Arlene is also the farthest north a tropical storm has formed in the Atlantic so early in the season.

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