MIDWAY, Fla. (WTXL) -- Many parts of the United States, including north Florida and south Georgia, run the occasional risk of rough weather. In such situations, the chances of severe weather are often described in levels of likelihood, such as "slight," "moderate," or "high" chances for severe thunderstorms and tornadoes.
These are not just arbitrarily assigned risk categories. These are official rankings used by a division of the National Weather Service to assess severe weather chances, a system that's been used for over three decades.
To further distinguish between heightened levels of severe weather potential, the Storm Prediction Center introduced two new risk categories: "Marginal" and "Enhanced."
Risk categories are assigned in daily forecast releases by the SPC. The new Marginal category lies below the "slight" category, meaning the chance of occurences of severe thunderstorms or tornadoes within the designed risk area is generally less than five percent.
The Enhanced category is assigned when the next-day risk is determined to be higher than the usual "slight" categorization, but falling short of the elevated Moderate ranking. An Enhanced risk indicates a 45% probability of severe hail or wind, a 30% chance of severe hail or wind along with a risk for extreme cases, a 15% tornado chance, or a 10% tornado chance along with possible stronger tornadoes.
The adjustments to the forecast categories were enacted in October 2014 after a review and feedback period. The Marginal and Enhanced categories were added to improve consistency between near-term and long-term severe weather forecasts.
