Tropical Storm Otto continues to weaken as it heads into the Eastern Pacific. As Hurricane Otto, this storm hit the coast of Costa Rica and Nicaragua as a Category 2 hurricane on the five-point Saffir-Simpson scale.

Hurricane season in the Caribbean Sea runs from the beginning of June to the end of November.

Nevertheless, Otto was the largest hurricane ever recorded in the region, likely the result of exceptionally high sea surface temperatures in the region – around 29C.

Nicaragua sustained at least four fatalities, with another five people reported missing.

The death toll could have been worse, had the storm not missed major population centres and passed across Central America’s largest lake, Lake Nicaragua.

Otto managed to remain largely intact as it passed across the low-lying ground of northern Costa Rica and southern Nicaragua, emerging as a 110km per hour tropical storm on the west coast of the country.

According to Jeff Masters of Weather Underground, in records dating back to 1851, Otto is the only tropical storm or hurricane whose centre moved over any part of Costa Rica, and the latest Atlantic hurricane to reach Category 2 strength in any year.

Otto is now more than 100km west of Costa Rica.

It continues to feed off warm surface waters and is expected to remain a tropical storm until the middle of next week.

Although computer models are struggling to handle a tropical storm this far south, so late in the year, Otto will remain a “fish storm”, eventually decaying over open water.