Miami, September 18 (RHC)-- Caribbean nations are bracing for the second powerful storm in as many weeks as Hurricane Maria approaches.   The Category 3 system, which is expected to strengthen significantly in the next 48 hours, is approaching the eastern Caribbean less than two weeks after Irma pummeled the region.

Hurricane warnings are in effect for Guadeloupe, Dominica, St. Kitts & Nevis, Montserrat, and Martinique, while a tropical storm watch is in effect for Barbados and St. Vincent and the Grenadines.

A hurricane watch is in effect for mainland Puerto Rico as well as Vieques and Culebra, U.S. Virgin Islands, British Virgin Islands, Saba, St. Eustatius, St. Maarten/St. Martin, St. Barthelemy (St. Barts) and Anguilla.

Tropical storm conditions are expected in Antigua and Barbuda, Saba and St. Eustatius, St. Lucia. Several of these islands suffered devastating damage from Hurricane Irma, one of the strongest and most sustained hurricanes in 30 years, earlier in September.

The Prime Minister of Dominica, Roosevelt Skerrit, held a news conference outlining the nation's disaster preparations as a hurricane warning was put in place. All schools will be closed, government meetings have been canceled and businesses are being advised to stay shut.

The Puerto Rican government is making preparations before the storm which could make landfall there on Tuesday.

Meanwhile, Hurricane Jose continues moving along a northern path at 9 miles per hour, packing 90 mph winds, just east of Cape Hatteras, North Carolina.

Tropical Storm Norma, which is still active, is located south-southwest of Los Cabos, Mexico packing maximum sustained winds of more than 50 miles per hour.

It triggered tropical storm warnings, meaning tropical storm conditions within 36 hours for parts of the peninsula, as the NHC forecast up to 20 inches of rain in isolated pockets which could "produce life-threatening flash floods."

Another system, Max, made landfall on Mexico's Pacific coast as a Category 1 hurricane Thursday night, but was downgraded and has largely dissipated.

It had threatened southern parts of the country including the state of Oaxaca which is still struggling to recover after it bore the brunt of the damage from an 8.2 magnitude earthquake that struck Mexico Sept. 7.

Last week, Hurricane Katia battered the Atlantic coast of Mexico and later blew itself out in the center of the country without causing major damage.

At the beginning of September, Tropical Storm Lidia left seven people dead on its stormy passage through the state of Baja California. 

Mexico is one of the countries most vulnerable to hurricanes because of its thousands of miles of coastline on both the Atlantic and Pacific and its proximity to the hurricane belt.