UPDATE 1-Hurricane Kay weakens slightly along Mexico's west coast, disrupts flights

(Updates with latest NHC report showing slight weakening)

MEXICO CITY, Sept 7 (Reuters) - Hurricane Kay weakened slightly by Wednesday afternoon, authorities said, as the Category 2 storm headed closer to Mexico's Baja California peninsula, causing flight cancellations throughout the region.

As at 5 pm ET (2100 GMT), the storm was located over the Pacific Ocean some 205 miles (335 km) west-southwest from the tip of the peninsula, home to the beach resort Cabo San Lucas, according to the Miami-based National Hurricane Center (NHC).

Although it is forecast to continue weakening, Kay is expected to remain a large hurricane when it passes near the west-central coast of the Baja California peninsula, the NHC said.

Mexican airlines VivaAerobus, Volaris and Aeromexico said in statements that Kay had prompted cancellations of domestic flights to the popular tourist region of Los Cabos.

Kay reached Category 2 intensity earlier in the day, with sustained wind speeds hitting 100 miles per hour (155 km per hour).

The NHC said a tropical storm warning had been activated for the Los Cabos area, while a hurricane watch and hurricane warning were in effect for other parts of the state of Baja California Sur, with heavy rains expected through Saturday.

Over the weekend, Kay killed three people in the state of Guerrero and in the port of Acapulco, on the Pacific Coast, as well as damaging houses. (Reporting by Isabel Woodford and Lizbeth Diaz; Additional reporting by Diego Ore; Editing by Anthony Esposito, Leslie Adler and Richard Pullin)