Red warnings issued for damaging winds, flooding rain and huge waves as Hurricane Gabrielle approaches the Azores.

L developed into Potential Tropical Cyclone Nine, increasing chances of impact on the U.S. coast, and Hurricane Humberto grew into a major Category 3

A Hurricane Warning has been issued for the Azores as Hurricane Gabrielle continues to barrel across the Atlantic.

Portugal's Azores archipelago cancelled all tourist and recreational activities for 24 hours and shuttered schools and public services on Thursday, urging people to stay indoors ahead of the arrival of cyclone Gabrielle.

Gabrielle will bring dangerous wind, rain and massive waves to the Azores late this week before shifting toward Spain and Portugal as a tropical wind and rainstorm.

Humberto is about 465 miles northeast of the northern Leeward Islands and is moving slowly toward the northwest. It is expected to strengthen substantially over the weekend to become a major hurricane, the Miami-based U.S. National Hurricane Center said.