Storms that ramp up so quickly complicate forecasting and make it harder for government agencies to plan for emergencies. Hurricane Erick, a Pacific storm that made landfall June 19 in Oaxaca, Mexico, also strengthened rapidly, doubling in intensity in less than a day.

Because of Hurricane Erin, Island Princess is stuck in New York, while Enchanted Princess is delayed in her return to New York.

Hurricane Erin dazzled forecasters over the weekend, putting on a spectacular show of strength rarely observed, becoming only the 43rd Atlantic-basin Category 5 hurricane on record and tying Camille in 1969 for the 4th earliest-forming Category 5 ever recorded.

Erin, the first hurricane of the season, exploded to a Category 5 hurricane Saturday, and despite fluctuations in intensity, the storm is remaining formidable this weekend. Here's where it could head in the week ahead.