Hurricane Gustav hit the United States a few hours ago with top wind speeds of more than 100mph. Hitting coastal Louisiana, Gustav is moving northwest at 15 mph.

Its hurricane-force winds extend 70 miles from the storm center, with tropical storm-force winds extending 200 miles from the center, with the area from High Island, Texas, to the Alabama/Mississippi border, including New Orleans and Lake Pontchartrain, under hurricane warning.

Heavy rains of 10-20 inches are expected over parts of Louisiana and southern Mississippi through Tuesday, with some areas already flooded. East Texas might be hit too with floods as Gustav slows up its pace while traveling over land.

Meanwhile, Hanna is a category 1 hurricane with top speeds of 75 mph.

Forecasters predict an above-normal season during 2008, which appears to be connected with the global warming. It is already known that hurricanes need a certain minimum water temperature in order to form, with warmer water generating more numerous and more powerful hurricanes.

This questions whether the United States will have to abandon forever the New Orleans, Miami and Houston areas in the following decades, should devastating hurricanes hit them every year or so.

The 2008 season could see as many as 14 to 18 named storms, up from an average of around 11 storms.