The european is showing a storm of tropical origin developing in close to the east coast in the long range. Currently a cold front is off the east coast and is forecast to move eastwards and leave some energy behind north of the bahamas. Here is the evolution of the current pattern across the atlantic basin.
A trough forms right under a blocking ridge across northeastern canada. This system will be forced back in towards the northeast coast.
Keep in mind this isn't just a few runs of the ECM operational but there is also ensemble support for a trough developing east of florida.