Tropical Storm Delta picked up speed in the central Atlantic and could bring near gale-force winds to the Canary Islands on Monday, forecasters said.

Delta, the 25th named storm of the record-breaking Atlantic hurricane season, had top sustained winds of 40 mph — just above the 39 mph threshold to be a tropical storm. Little change in strength was expected in over the day, but forecasters expected it to lose the characteristics of a tropical storm Sunday night or Monday.

Yet Delta could still bring strong winds Monday to the Canary Islands, off the northwestern coast of Africa, according to the National Hurricane Center in Miami.

At 4 a.m. EST Sunday, Delta was about 945 miles west-southwest of La Palma in the Canary Islands and moving northeast near 24 mph.

The six-month Atlantic hurricane season officially ends Wednesday, but forecasters warn that tropical storms and hurricanes can develop in December.