Otto on Monday became the 15th named storm – one with winds of at least 39 mph -- of a generally busy Atlantic hurricane season on Monday.
With peak winds of about 50 mph it was about 315 miles east of Nicaragua late in the day, and wasn't showing much signs of moving.
The National Hurricane Center forecast that it would grow into a minimal Category 1 hurricane, with top winds of 75 mph, as it approached the Central American coast late Wednesday.
It was forecast to cross Central America, and it was not clear what would be left of it as it entered the Pacific Ocean.
It will pose no threat to the U.S. mainland, and with season officially down to its final nine days, it appears that one more year will be added to the record streak of the nation's good fortune.
Officially, 2016 would qualify as an above-average season for tropical-storm activity in the Atlantic Basin, which includes the Gulf of Mexico and the Caribbean Sea.
The average number of named storms during the season, which runs from June 1 to Nov. 30, is 11; the average for hurricanes is six.
Matthew caused widespread flood devastation last month, as did Sandy, in 2012, although officially it was not a hurricane when it made landfall.