A powerful oddball storm scenario to impact the Northeast that could become Wanda

Two strong weather systems are forecast to merge off the Northeast coast and produce a powerful nor’easter-type storm. But before and after that happens, there will be windows of opportunity for a tropical-like system named Wanda to develop as part of the meteorological witch’s brew.

A northern low-pressure system, which produced tornadoes in the Midwest, is forecast to merge with a southern system that developed off the Southeast coast. The new system will become an extremely strong nor’easter later today or tonight offshore of Long Island, New York. The combo storm will generate heavy rain and dangerously strong winds. Alerts for hazardous weather are in effect for parts of the Northeast and New England.

Before the southern system gets fully absorbed, it has a slight chance of becoming an independent tropical system over the Gulf Stream and the unusually warm water off the Northeast coast. Then in a few days, as the powerful nor'easter moves into the open Atlantic, it will cross the Gulf Stream again and again have a chance of becoming tropical enough to meet the criteria necessary to get a name. The next name on the list is Wanda.

The combo nor’easter – in between its tropical opportunities – is forecast to produce damaging winds along the Northeast and New England coasts and flooding rain in the big cities and the surrounding areas. This is the first nor’easter of the season, but it’s forecast to be an exceptionally strong one. Strong winds will be felt across the Northeast, and gusts over hurricane force are possible on Cape Cod tomorrow.

A nor’easter is a winter-type storm that is powered by contrasting cold and warm air masses, as opposed to tropical systems, which are powered by the heat of the ocean. The system that is forecast to develop today is an unusual combination of multiple atmospheric elements that are lining up in an optimal way to generate a powerful storm with tropical possibilities.

From a naming standpoint, the question is whether it will at some point use the warm Gulf Stream water as all or part of its energy source. If it gets a name, it will be for that technical reason. In any case, the system will head out to sea by late tomorrow.

Elsewhere, there are no signs of any tropical development this week and beyond.