A storm is developing off the North Carolina coast this afternoon that will have significant impacts on the region which will include heavy rainfall and strong winds.
This storm has a tropical component to the development and there is a chance that this storm may reach tropical storm or subtropical storm strength. I want to be clear, regardless if this storm is named or not, the impacts will be the same as the difference in the sustained winds for this forecast is basically 10 mph in a few locations. The primary concern with this storm will be the rainfall, not the winds.
The storm will approach the region tonight with rainfall developing over southern New Jersey between 5 AM and 6 AM in the morning. As the surface low-pressure system lifts towards the Delaware coast, periods of moderate to heavy rainfall will expand northward from south to north through the morning hours.
The low-pressure system center is now expected to track along the Delaware coast through tomorrow morning and then along or just off the New Jersey coast through tomorrow afternoon, and then into Hudson River Valley tomorrow night on through Saturday morning. A shift east or west of this storm track will shift the expected rainfall totals east or west, however, at this time there is a high level of confidence for this forecast.
In addition to the heavy rain impacts which may produce urban, stream, and river flooding, there will also be a wind impact to consider. Away from the coast, sustained winds will range from 5 to 15 mph. However, along the immediate coast and including all of Long Island, sustained winds are expected to range from 15 to 30 mph with gusts over 40 mph at times within intense rain bands.
The storm is expected to exit on Saturday morning with a break in the rainfall on Saturday afternoon. A cold front will follow in the evening with additional scattered showers and thunderstorms. For most locations, dry conditions are now expected on Sunday.