Tropical Storm Lidia has strengthened into a hurricane late as it approaches west-central Mexico, the US National Hurricane Center says, warning of dangerous winds and heavy rains that threaten flooding across large stretches of the Pacific coast. Hurricane-force winds and flooding rains should begin to hit Mexico on Tuesday, the centre said. Lidia was about 600km off the popular resort city of Puerto Vallarta, the NHC said in its latest bulletin on Monday, moving east-northeast at 16km/h with sustained winds reaching up to 120km/h. The NHC warned of hurricane conditions from southern Jalisco state up to the Islas Marias off the Nayarit coast, and tropical storm conditions stretching north to Mazatlan and south to Manzanillo. The hurricane should bring up to 30cm of rain through Wednesday across Nayarit, Jalisco and southern Sinaloa, it said, threatening flash and urban flooding. A storm surge could also produce "significant coastal flooding" around where Lidia makes landfall, it added. The forecaster urged residents to complete preparations to keep themselves and their property safe as winds become increasingly dangerous. Strong swells should also affect the Baja California peninsula, it added. This comes as Storm Max, which hit the southern state of Guerrero on Monday, weakens as it travels inland. The NHC warned that Max would bring strong winds across the southern coastline Monday night and could still produce flash flooding and mudslides across Guerrero and neighbouring Michoacan states. Australian Associated Press