What Isaias' East Coast Track Could Mean for the Mid-Atlantic, Northeast

Isaias is forecast to move close to Florida this weekend. Heavy rain, strong winds, coastal flooding and life-threatening rip currents are concerns in eastern Florida through Sunday.

(MORE: Isaias Forecast)

Attention will then turn farther north. Isaias will take a turn toward the north-northeast, likely when it is near or off the Southeast coast early next week.

The timing of this turn is important for determining how close Isaias will move to the mid-Atlantic and Northeast. This turn will be influenced by an approaching cold front that will be pushing into the East early next week. How fast this front slides eastward, the strength of an upper-level trough and the intensity of Isaias, will all play key roles in determining its final path.

The exact track of Isaias will decide how strong this system is from the Carolinas to Maine. A track over the inland Carolinas will bring a weaker storm northward while a track up the right side of the cone would bring a stronger storm northward.

It is likely that multiple landfalls will occur from the Carolinas northward, which will spread heavy rain and gusty winds well inland.

How fast Isaias moves northward is also unclear which would change when impacts would be felt in the mid-Atlantic and Northeast. Recent trends have suggested a slower forward movement, meaning tropical storm conditions would occur a little later.

Potential Impacts, Timing

If Isaias tracks along the eastern edge of the projected path shown above, then most impacts will be periods of rain and gusty winds There would likely still be coastal concerns in the Carolinas, but the Northeast would generally only expect higher surf and dangerous rip currents.

A track farther west would increase concerns throughout the mid-Atlantic and Northeast. The risk of heavy rain, strong winds, tornadoes, coastal flooding and erosion would be higher with a more westward path.

It is also important to point out the impacts often occur outside of the red shaded areas, so it is important not to focus on the center of the cone of uncertainty.

Monday-Tuesday

Isaias may be located near or off the Southeast coast around Monday depending on its forward speed.

Coastal flooding, beach erosion and rip currents are also possible along the coasts of Georgia and the Carolinas. Coastal inlets including Charleston Harbor, the Pamlico and Neuse Rivers, and the Pamlico Sound may have rises as Isaias moves northward.

Impacts could also extend farther north into the Delmarva Peninsula early Tuesday.

Tuesday-Wednesday

Rain and wind may spread northward into the Northeast Tuesday into Wednesday.

Impacts will likely be greater toward the coast. Coastal flooding and beach erosion are possible in some areas.

Rainfall

Rain and thunderstorms are expected separate from Isaias. One disturbance will bring the chance for showers and storms this weekend into early week and then the cold front mentioned previously will bring another round of rain and thunderstorms behind Isaias.

Isaias combined with the additional systems will bring moderate rainfall to much of the East. The track of Isaias will determine where heavier rain falls, and where flooding will be a greater concern.

Some rainfall is good news as just under 30% of the Northeast is in drought, with 70% of the region at least abnormally dry, according to the U.S. Drought Monitor. Heavier rainfall over a relatively short period of time could be too much of a good thing.

A zone of heavier rain appears likely from the eastern Carolinas to the mid-Atlantic.

The exact details of the forecast will come into better focus after Isaias makes its turn northeastward, so be sure to check back frequently for updates in the days ahead.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.