POSSIBLE HURRICANE/TROPICAL STORM/SUB-TROPICAL STORM INTO LATE MAY/EARLY JUNE. The GFS has been showing the development of a tropical system in the Western Caribbean. From it's development, it moves north possible effecting South-eastern Florida, then moving tangent to the east coast, until it retrogrades around Cape Hatteras due to a blocking high to the north, if the blocking high to north moves more east, it will then allow the storm to continue it's move up the east coast, possible effecting the entire east coast. There is still a good chance that this could also blow out to sea, and not effect land at all (except in the Caribbean). If it does effect the east coast, its strength is uncertain; water temperatures off the southeast coast should be around 80 by late May/early June (higher water temps possible with the Gulf Stream); and water temps along the Mid-Atlantic and New England coast should be in the 60's, 50's near Maine. Water temps in the 60's could make this a sub-tropical/extra-tropical event, but still powerful. As the storm retrogrades, it could gain intensity, if it then gains momentum from a strong jet, it could move fast enough where it would not loose much intensity and could effect the Mid-Atlantic and New England as a strong topical storm or hurricane. If that scenario doesn't happen, the storm could move out to sea, or effect us as a sub-tropical storm. Again, this way far out to tell what might happen. We'll have to wait and see.
Here's a look at the storm from the GFS 12z model run @ (May 29th, 12z):