MEXICO CITY — Hilary strengthened into a Category 2 hurricane off Mexico's Pacific coast Thursday, and it could bring heavy rain to the U.S. southwest by the weekend.

The U.S. National Hurricane Center said that Hilary had maximum winds of 105 mph and could perhaps skim the coast of the Baja California peninsula by the weekend.

Hilary was located about 500 miles south-southeast of Los Cabos, on the southern tip of the Baja peninsula. While it was still far from land, the hurricane was moving west-northwest at 14 mph and was expected to take a more northward turn, toward the U.S. border.

It was expected to become a major hurricane by Friday and perhaps skim the sparsely populated western edge of the Baja coast. The hurricane center said it could possibly survive briefly as a tropical storm and cross the U.S. border.

No tropical storm has made landfall in Southern California since Sept. 25, 1939, according to the National Weather Service.

"Rainfall impacts from Hilary within the Southwestern United States are expected to peak this weekend into Monday," the hurricane center wrote in a report. "Flash, urban, and arroyo flooding is possible with the potential for significant impacts."

The area affected by heavy rainfall may include the stretch between San Diego, California and Yuma, Arizona. A wider area between Bakersfield, California and Tucson, Arizona could also see rain.

The outlook for excessive rainfall in Southern California stretches from Sunday to Tuesday, according to the Los Angeles weather office.

The odds are against Hilary making landfall in California as a tropical storm but there is a high chance of major rain- and flood-related impacts, UCLA climate scientist Daniel Swain said in an online briefing Wednesday.