From Dr. Jeff Masters:
Hurricane Dean is headed west towards the Yucatan, still packing Category 4 winds, with the potential to add even more punch. Dean is over waters with some of the highest heat content anywhere in the Atlantic, and could well take advantage of this energy source and become a Category 5 hurricane today. Landfall will occur late tonight or early Tuesday morning over the Yucatan Peninsula. Landfall should occur over 100 miles south of Cozumel, so the Mexican Riviera areas of Cancun and Cozumel will only experience tropical storm force winds. The region where Dean is expected to hit, just north of the border with Belize, has one large city, Chetumal. Chetumal is well inland, and the expected storm surge of up to 11 feet will mostly flood very sparsely populated areas. Damage from Dean in Mexico may be considerably higher for the storm's second landfall, if it hits the major city of Tampico in the western Gulf of Mexico.