Forming in October, Otis grew stronger by churning up deeper and warmer water because it was later in the year. Erick is early in the year and the deep water it would churn up is cooler and doesn’t fuel rapid intensification. Even so, the surface water is plenty hot enough, said MIT hurricane scientist Kerry Emanuel.

The National Hurricane Center said Tropical Storm Erick is expected to rapidly strengthen into a hurricane on Wednesday.

Erick is expected to become a Category 3 major hurricane by the time it makes landfall early Thursday morning.