Possible System in the Atlantic by the Weekend (Mid-Range Outlook)

Atlantic Tropical Cyclone Genesis Potential
Mid Range Outlook: 48 to 168 hours (3-7 days)
Hurricane Analytics
Date/Time Range: Thursday at 5:00PM EDT 9/25/2013 to Monday 5:00PM EDT 9/30/2013

Note: This is an experimental (beta) forecast product

Forecast Event: Coastal/Subtropical or Tropical Storm Development
Indicated By: Computer Models
Possible Impacts: Elevated storm surge and tropical storm force winds
Possible US Locations: Eastern United States from North Carolina northward to Maine

Event Summary: Global computer models are forecasting the development of a subtropical or tropical storm off of the east coast of the United States. The area is forecast to begin as a large, broad area of low pressure southeast of the US coast by Thursday afternoon, and could evolve into a subtropical or even tropical storm by Saturday or Sunday, as depicted by the latest European model run as of Tuesday afternoon. This is the second run in a row showing a similar evolution, which is why Hurricane Analytics is initiating coverage.

Looking into the 5 to 7 day forecast period, the European model not only develops this system, but it also is forecasting a steering pattern which would potentially bring it toward the northeast US coast very late in the week or early next weekend.

The GFS computer model is also suggesting some development in this general area, however, it does not forecast a pattern favorable for a US landfall at this time, nor has it shown such a pattern over the course of the last several runs of the model. It is impossible to know which model has a better handle on the situation, but reportedly the GFS has a history of having an underdevelopment and eastward bias with developing coastal lows.

The National Hurricane Center is not currently showing this system in their 5 day forecast product as of 2:00PM on Tuesday 9/24. However, we would not be surprised if they begin discussing it in upcoming outlooks.

Next outlook: 9:00AM EDT on Wednesday, 9/25/2013

About Michael Watkins

Mike Watkins is the founder of Hurricane Analytics, a private organization specializing in data visualization and predictive analytics, with a special focus on tropical meteorology. They analyze complex meteorological data and communicate that information in easy-to-understand terms, to help clients prepare and anticipate the disruptive impact of Atlantic hurricanes.