Tropical Storm Isaias Heads to Florida

08-05-20 12:37 PM Comment(s) By Jessica Gutheil

These graphics show probabilities of sustained (1-minute average) surface wind speeds equal to or exceeding 34 kt (39 mph). These wind speed probability graphics are based on the official National Hurricane Center (NHC) track, intensity, and wind radii forecasts, and on NHC forecast error statistics for those forecast variables during recent years. Each graphic provides cumulative probabilities that wind speeds of at least 39 mph will occur during cumulative time periods at each specific point on the map. The cumulative periods begin at the start of the forecast period and extend through the entire 5-day forecast period at cumulative 12-hour intervals (i.e., 0-12 h, 0-24 h, 0-36 h, ... , 0-120 h). An individual graphic is produced for each cumulative interval, and the capability to zoom and animate through the periods is provided. To assess the overall risk of experiencing winds of at least 39 mph at any location, the 120-h graphics are recommended.


These probabilities will be updated by the NHC with each advisory package for all active tropical cyclones in the Atlantic and eastern North Pacific basins. While separate graphics are focused on each individual tropical cyclone, probabilities resulting from more than one active tropical cyclone may be seen on each graphic.


It is important for users to realize that wind speed probabilities that might seem relatively small at their location might still be quite significant, since they indicate that there is a chance that a damaging or even extreme event could occur that warrants preparations to protect lives and property.


Additionally, these probability products are available on the National Weather Service's National Digital Forecast Database (NDFD) graphical tropical webpage.
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