(Updates with Gabrielle strengthening)
By Jane Sutton
MIAMI, Sept 10 (Reuters) - Tropical Storm Gabrielle regenerated and took aim at Bermuda on Tuesday while Tropical Storm Humberto strengthened on the cusp of becoming the season's first Atlantic hurricane, forecasters said.
The burst of activity came right on schedule as the Atlantic-Caribbean storm season hit its traditional peak.
Gabrielle was expected to pass near or directly over the mid-Atlantic island of Bermuda by Wednesday morning, forecasters at the U.S. National Hurricane Center said.
Its top winds jumped to 50 mph (85 kph) on Tuesday afternoon, up from 40 mph (65 kph) a few hours earlier, and it could strengthen on its approach to Bermuda, they said.
Gabrielle was about 95 miles (155 km) south of Bermuda, which can expect rough seas, gusting wind and rainfall by Tuesday evening, the forecasters said. Several flights to Bermuda were canceled in anticipation of the storm.
The affluent British territory has strict building codes and tends to withstand tropical storms without major damage.
Gabrielle first formed last week in the northeastern Caribbean, soaking Puerto Rico as it crossed into the Atlantic. It fizzled quickly, but regrouped during the weekend and became a tropical storm again on Tuesday.
On its current track, after dusting Bermuda, Gabrielle would curve north toward Nova Scotia and Newfoundland, the hurricane center said. It was expected to remain a tropical storm until it approached Newfoundland on Saturday.
Tropical Storm Humberto formed on Monday in the eastern Atlantic near the African Coast and brushed by the southern Cape Verde Islands. It was about 150 miles (240 km) west of Cape Verde on Tuesday morning, headed north over open waters and posed no threat to land.
Humberto had top winds of 65 mph (100 kph) and was expected to cross the 74 mph (119 kph) threshold to become a hurricane on Tuesday.
It is the eighth tropical storm of the Atlantic-Caribbean hurricane season, which runs from June 1 to Nov. 30 and historically peaks on Sept. 10. But it would be the first this year to reach hurricane strength.
The first hurricane of the season usually forms by Aug. 10.
Since the dawn of the satellite era in the mid-1960s, the latest date for the first hurricane to arrive was set in 2002 when Hurricane Gustav made its debut on Sept. 11.
If Humberto reaches hurricane status after 8 a.m. EDT (1200 GMT) on Wednesday, it would replace Gustav as the modern-day record holder, the forecasters in Miami said. (Reporting by Jane Sutton; Editing by Doina Chiacu)