Rick is centered about 340 miles (547 kilometers) southwest of Manzanillo, Mexico.
The newly-formed system is expected to strengthen to Tropical Storm Rick in the coming days.
Many tourists were earlier ordered by staff at their hotels to make for the city's convention center, which was designated by emergency services as a main shelter.
En Cihuatlán, Jalisco, decenas de casas se inundaron
Los pobladores saben que el impacto del fenómeno más poderoso del planeta —como lo calificaron las autoridades— podría ser mayor
Forecasters say the storm is capable of "potentially catastrophic" damage.
Patricia's maximum sustained winds had increased Thursday to 130 mph (215 kph) - already Category 4 strength - and forecasters said it could grow even stronger before slamming into land.
Shipping hubs Manzanillo and Lázaro Cárdenas are both within a hurricane watch area set by the NHC.
Between 2006 and August 2015, 1,323 drug laboratories were seized in Mexico.