ACAPULCO, Mexico (AP) -- Forecasters are expecting Tropical Storm Andres to grow into the Pacific season's first hurricane Tuesday.

They say it will likely deal a glancing blow to southwestern Mexico before churning its way up the coast.

Mexico has issued a hurricane warning for the Pacific coast from just south of Manzanillo north to near Puerto Vallarta. To the south, officials in Acapulco have prepared 120 shelters and are warning residents to stay indoors, especially some 15,000 people in zones most at risk for flooding.

At last report, the U.S. National Hurricane Center put Andres' center about 160 southeast of Manzanillo with maximum sustained winds near 65 mph with higher gusts.