Hurricanes will strike land this weekend by two different oceans

Two hurricanes will strike land this weekend by two different ocean basins - Tammy in the Atlantic and Norma in the eastern Pacific.

Neither are a threat to the US, but Norma has triggered hurricane warnings for Mexico, including the popular resort town of Cabo San Lucas, and Tammy for portions of the Leeward Islands, a chain of several island nations between the Caribbean Sea and the open Atlantic.

Tammy strengthened into a hurricane with sustained winds of 75 mph on Friday morning and is forecast to continue slowly strengthening as it tracks through the Leeward Islands. Hurricane-force winds extend outward up to 25 miles from the storm's center and tropical storm-force winds extend outward up to 140 miles.

Hurricanes in this part of the Atlantic are rare for late October. Tammy is only the third hurricane to form this far southeast in the Atlantic since 1900, according to hurricane expert Michael Lowry.

It's also the latest-forming hurricane in this part of the Atlantic since 1966, according to Phil Klotzbach, a research scientist in the Department of Atmospheric Science at Colorado State University.

Hurricane experts previously warned hurricanes could form in unusual areas later in the season this year because of the exceptionally warm Atlantic Ocean.

Hurricane conditions, including strong winds and heavy rain, are expected in the Leeward Islands by late Friday and into early Saturday. A storm surge of 1 to 3 feet is forecast for the islands.

Heavy rainfall will be one of the storm's most serious threats and could result in flash flooding and mudslides. Rainfall totals for the Leeward Islands are expected to be 4 to 8 inches, but could reach a foot in places where the heaviest rain sets up. Rain should be lighter in Puerto Rico and the British and US Virgin Islands, where 1 to 2 inches of rain is most likely.

Conditions will begin to improve from south to north across the island chain starting late Sunday as the storm moves north out of the region.

With Tammy in the Atlantic there are now only two names left - Vince and Whitney - on the standard Atlantic storm name list before the hurricane center turns to an alternate list of names.

Category 2 Hurricane Norma had winds of 110 mph and even higher gusts Friday afternoon and was located about 255 miles west-southwest of Manzanillo, Mexico.

The storm is expected to weaken as it makes its approach to the southern portion of Mexico's Baja California Sur on Saturday.

Conditions will start to deteriorate in southern Baja California Sur, including Cabo San Lucas, on Friday night. Tropical storm conditions will ramp up to hurricane conditions by early Saturday.

The storm will bring heavy rainfall and flooding to the area through Sunday. Rainfall totals of 5 to 10 inches with isolated totals approaching 15 inches are possible through Sunday across the far southern portion of California Baja Sur.

"These rains will likely produce flash and urban flooding, along with possible mudslides in areas of higher terrain," the National Hurricane Center warned.

After raking Baja California Sur, the storm will then make a turn to the east, cross the Gulf of California, and make landfall somewhere along the eastern coast of mainland Mexico by early Monday.

CNN Meteorologist Rob Shackelford contributed to this story.