First Tropical Depression of Season May Develop off of Southeast Coast

The potential impacts to the weather next week across the Mid-Atlantic continues to get more interesting with the National Hurricane Center watching a disturbance (red X in the image below) located just off of the South Florida coast.  This system may become a tropical depression (or sub-tropical depression) later today or tonight with the potential for further strengthening into a tropical storm before it moves northeast up the Mid-Atlantic coastline Tuesday into Wednesday.

Depending upon how this system interacts with an upper-level “cut-off” low pressure system moving eastward out of the Ohio and Tennessee valleys during the upcoming week will determine whether there are any direct impacts along the coast and how much rain falls inland across the Mid-Atlantic.

The European and GFS models below (courtesy Pivotal Weather) show disagreement in eventual track of this system, but one thing that both models do indicate is the potential for substantial amounts of rain.

The Latest European Model

The ECMWF (European model) below keeps the sub-tropical or tropical/depression/storm offshore however heavy rain still threatens the Mid-Atlantic due to the stalling upper-level low to our west drawing in ample moisture from the Atlantic ocean.

The Latest GFS Model

The GFS shows the tropical system hugging closer to the coast as it moves toward southern New England while the upper-level low continues to meander over the DC Region through Thursday.

The Latest 5 Day QPF (Quantitative Precipitation Forecast) from the Weather Prediction Center (WPC)

This forecast image (courtesy NOAA) below will likely change with time as the models continue to ingest the latest data.

Based on the current trends, it appears that the potential for a widespread one to four inches of rain is increasing during the next five days.  How long the cut-off low stalls in our region and the exact track of the tropical system will determine if some locations pick up more than four inches of rain.