Tropical Storm Andres formed overnight off the southwestern coast of Mexico, becoming the first named storm of the season in the Eastern Pacific and the latest arrival in 40 years, forecasters said Monday.

The Eastern Pacific hurricane season runs from May 15 to Nov. 30 and is typically busiest between July and September.

"Normally that season gets under way somewhat earlier," said Richard Pasch, a senior hurricane specialist at the National Hurricane Center in Miami, Florida. "But it's not necessarily an indication that it'll be a quiet year in that basin. We've seen some years starting late and become quite active. We're just going to have to wait and see on that."

Federal forecasters have predicted a near-normal or below-normal season, with the possibility for 13 to 18 named storms, including six to 10 hurricanes.

Most forecasting models did not predict the storm's center to make landfall, but it does carry the threat of heavy rains over the next two days as it is predicted to turn toward the northwest and skirt the coast.

A tropical storm watch was issued from Zihuatanejo northward to Manzanillo, meaning tropical storm conditions were possible in the next day or two.

The National Hurricane Center said Andres' center as of 2 a.m. EDT (0600GMT) was about 200 miles (325 kilometers) south of Zihuatanejo and 330 miles (530 kilometers) south-southeast of Manzanillo.

Andres was moving slowly toward the west-northwest near 5 mph (7 kph). Maximum sustained winds were near 45 mph with higher gusts.

The storm earned its name late Sunday when its winds exceeded a sustained 39 mph (63 kph). It gained strength early Monday and was expected to continue gaining strength over the next day or two, but forecasters said they didn't expect it to reach hurricane strength.