Weather Tidbits: Severe Weather Risk Categories

This edition of Weather Tidbits will discuss the severe weather risk categories. The Storm Prediction Center uses these categories in their products when forecasting severe weather, which is then available for public viewing.  The product is divided into 5 levels. Those levels from 1 to 5 respectively are MARGINAL, SLIGHT, ENHANCED, MODERATE, and HIGH.

An area under a MARGINAL risk for severe weather will feature a threat of isolated severe weather. Any severe thunderstorms that do form are usually limited in organization, longevity, and coverage. The storms will generally be at a base severe level (58 mph wind or greater, hail 1″ or greater in diameter, and/or a weak tornado). A SLIGHT risk will feature a greater coverage of severe weather with better organization of storms, though not widespread. A few storms could be significant (75 mph or greater, hail 2″ or larger, and/or a tornado EF2 or higher), but it is not likely.

An ENHANCED risk will feature an even greater coverage of severe storms in which several storms could be significant. A MODERATE risk could feature many storms where significant tornadoes, large hail, and damaging winds are likely. A HIGH Risk will likely feature an outbreak of significant storms with numerous long-track violent tornadoes and destructive storms. The HIGH risk is rarely issued.