Tropical Cyclone Genesis

The National Hurricane Center (NHC) is currently issuing advisories on Tropical Depression Two in the eastern Atlantic and is forecasting it to be a few hundred miles north of the Leeward Islands as a Tropical Storm in five days time.

In addition, the NHC’s Tropical Weather Outlook (TWO) is mentioning the vigorous tropical wave between the Cape Verde Islands and Africa and giving this system a low chance, less than 30 percent, of it becoming a tropical cyclone during the next couple of days.  Local 10 aims to be consistent with the NHC and mentions the more significant tropical disturbances in the TWO.

Satellite image from 12 August 2009 showing TD TWO and the vigorous Tropical Wave between the Cape Verde Islands and Africa

Satellite image from 12 August 2009 showing TD TWO and the vigorous Tropical Wave between the Cape Verde Islands and Africa

We are paying extra attention to the wave over the far eastern Atlantic because some of the global forecast models (including from the United States Global Forecast System, the European Center for Medium-Range Weather Forecasts, and Canada) are showing significant development of this system over the next few days as it moves westward across the tropical Atlantic.

Given the models’ indication of a strong tropical cyclone developing from the tropical wave over the far eastern Atlantic, one may ask why the NHC is only giving a low probability of development.  It is important to note that the TWO discusses areas of disturbed weather and their potential for tropical cyclone development during the following 48 hours.  The NHC does not forecast genesis beyond two days because there is little skill in doing so.  Hopefully, the model guidance will improve and the day will come when longer range genesis can be reliably forecast.

Time will tell whether the vigorous tropical wave develops into a significant tropical cyclone or not.  It would not be unusual to see such development during the peak of the hurricane season.  The take away message should be that this would be a pretty good time over the next few days to review your hurricane plan as we continue into the heart of the season.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s