The first hurricane of the 2011 Atlantic season was leaving Puerto Rico and moving toward the northern coast of the Dominican Republic and Haiti Monday morning.

And if Hurricane Irene follows the forecast storm track, it can be expected to steer a bit more to the north later this week and threaten the east coast of Florida, Georgia and the Carolinas. Miami forecasters are predicting tropical storm conditions there by Thursday. AccuWeather.com is forecasting landfall late Saturday in the Carolinas.

And at least one forecast model is predicting a very heavy rain/wind/surf event for the mid-Atlantic coast early next week. 

Top sustained winds at Irene's center were blowing at 80 mph, making this a mid-range Category 1 hurricane for now. But some further strengthening is expected in the next few days.

Hurricane Warnings have been dropped for Puerto Rico and nearby islands, replaced by Tropical Storm Warnings.

Hurricane Warnings have been posted for the north coast of Hispaniola. Hurricane Watches are up for the south coast of the Dominican Republic and Haiti. Tropical Storm Warnings are in place for Puerto Rico, the U.S. and British Virgin Islands, all of Haiti and the south coast of the Dominican Republic, as well as the southeastern Bahamas and the Turks and Caicos Islands.

Five to 10 inches of rain are possible in Puerto Rico, the Virgin Islands and Hispaniola as Irene blows by. As much as 20 inches are possible in some locations. Storm surges of 1 to 4 feet are expected, with large and dangerous waves.

The National Hurricane Center is watching the atmosphere to Irene's north, where high pressure is keeping the storm from curving north into the open Atlantic. Instead, it is being steered west, closer to the U.S. coast.

Computer models differ on how close to the coast the storm will get. But there does appear to be some agreement that it will continue to strengthen. The forecast discussion says:

"IT WOULD NOT SURPRISE ME IF THIS CYCLONE BECAME A MAJOR HURRICANE AT
SOME TIME DURING ITS LIFETIME"

Here is the latest advisory for Irene. Here is the forecast track. Here is the forecast discussion.

Jeffrey B. Halverson, associate professor of geography and environmental systems at UMBC, is watching Irene's progress. He sent the latest GFS model results (for Monday, left). He said:

"For three days now, it has been portending a significant heavy rain event for the Mid Atlantic, and wind/high surf along the Eastern Shore. The track, heavy rain footprint and slow speed of the storm through the Mid Atlantic continues to look very Agnes (1972)-like."

AccuWeather.com's Alex Sasnowski, said, "It is very possible strong tropical storm or even hurricane conditions will continue to spread up the Atlantic Seaboard.

"If the fats forward motion of the storm continues, it could spread damage, including that of downed trees, power lines and coatal flooding issues, into the mid-Atlantic late this weekend and into southern and eastern New England by early next week."