"This one's going to affect everybody as it goes up the coast. We don't see it moving far out to sea and skipping a few of the places that in the past it had skipped," National Hurricane Center Director Bill Read said.
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As the storm clears the Bahamas and continues over the warm water of the Atlantic, its wind speed is expected to strengthen and the size of the storm could increase to a category 4 with wind speeds of at least 131 mph.
It is expected to weaken somewhat as it claws its way up the coast, but will likely still be packing winds of 50 to 70 mph when it reaches New York City and Boston. It is expected to dump 6 to 12 inches of rain on the Jersey shore, Long Island, Massachusetts and Connecticut.
In North Carolina, the roadways are clogged as tourists and locals flee to get ahead of the storm. Particularly worrisome are the low lying Outer Banks.
Capt. Al Foreman has been a charter boat captain for 40 years on the Outer Banks and fears this storm might be the worst he's seen.
"Everything is so low here on the Outer Banks, nothing is built really high. It wouldn't take much of a storm surge to do a lot of damage," Foreman said.
The Navy is preparing to move 126 warships, the entire Second Fleet, out of Irene's path.
What's making Irene's fury unique is not only it's size at 750 miles wide, but its slow pace.
"It's already a fairly large storm and as it moves northwards, it's going to get even larger and very important, this one on our forecast is moving slower by quite a bit than the average storms," Read said. "It gives more time to build up the tidal elevations and the storm surge that will be associated with this storm. It's too early to pinpoint, but there's a large area of the coast that may be impacted by the dangerous storm surge on this path."
Irene is expected to move at 15 to 20 miles per hour as it crosses the northeast, Read said. A typical storm moves at 25 to 35 miles per hour.
Behind Irene, another tropical depression formed in the Atlantic. The National Hurricane Center says the depression could be Tropical Storm Jose later today.
ABC News' Steven Portnoy and the Associated Press contributed to this report.