Atlantic Tropical Cyclone Genesis Potential
Mid Range Outlook: 48 to 168 hours (3-7 days)
Updated at 9:00AM EDT 9/25/2013
Outlook Date/Time Range: Friday at 5:00AM EDT 9/27/2013 to Tuesday 5:00AM EDT 10/1/2013
Note: This is an experimental (beta) forecast product…graphics coming soon.
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 Friday 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 Wednesday morning. This is the third run in a row showing a similar evolution.
Looking into the 5 to 7 day forecast period, the European model has shifted to the east with the eventual track of the low, keeping it just off of the US east coast. The latest GFS guidance is also showing a similar track, indicating the steering pattern would not have enough of a westward component to bring the core of the system back to the US.
However, these forecast solutions are in the 6+ day time periods, and much can change over the course of just a couple of model runs. It’s too early to dismiss possible impacts to the US, although the model trend is encouraging.
The National Hurricane Center is not currently showing this system in their 5 day forecast product as of 8:00AM on Wednesday 9/25. Either they are expecting development further out than 5 days, or they anticipate the system will not have enough tropical characteristics to be under their area of responsibility. NHC forecast products will continue to be monitored for subsequent information on this system.
Next outlook: 5:00PM EDT on Wednesday, 9/25/2013