Tropical Cyclone Wind Speed Probabilities Products

Contents

1. Overview
2. Description of the tropical cyclone wind speed probabilities text product
3. Description of the tropical cyclone wind speed probabilities graphical products
4. Description of the tropical cyclone NDFD wind speed probabilities products
5. Potential advantages as compared to previous products
6. Method for computing the wind speed probabilities

5. Potential advantages as compared to previous products

The TPC/NHC has been issuing other products intended to convey the uncertainties in the track forecast. However, those products do not account for the uncertainties that also exist in the forecast of the cyclone's intensity and size.

The discontinued strike probabilities text product was a statement about the "close" approach of the center of a tropical cyclone. However, the wind speed probabilities products are about the weather. That is, the wind speed probabilities provide the chances of wind speeds equal to or exceeding familiar thresholds (for example, tropical storm force and hurricane force) at individual locations. Therefore, these probabilities likely have more direct meaning and impact to users. Also, while the previously available strike probabilities only provided forecast information out to three days for just the Atlantic basin, the wind speed probabilities provide information out to five days for both the Atlantic and Eastern Pacific basins.

TPC/NHC also continues to provide a watch/warning graphic that also displays the forecast track and a "cone of uncertainty". The cone depicts the long-term average error in the forecast of the track of the cyclone center. It is important to remember that the effects of a tropical cyclone can be experienced well away from the center of the cyclone and well outside of the cone of uncertainty, since the actual path of the center does not always stay within the cone, and since tropical cyclones vary in intensity and size. The wind speed probabilities provide more direct information about what wind conditions could be experienced at specific locations both inside and outside of the cone.

Overall, the wind speed probabilities have the potential to provide users with information that enhances their ability to make preparedness decisions specific to their own situations.

Next:  Method for computing the wind speed probabilities