Winter Storm Severity Index Product

(Abbreviated WSSI Product.) A National Weather Service graphic and text product by the Weather Prediction Center that allows forecasters, stakeholders, and the general public to maintain situational awareness of "Winter Weather Areas." It communicates the spatial distribution of potential weather impacts, which are categorized as minor, moderate, major, and extreme for snow amount, snow load, ice accumulation, blowing snow, and flash freeze. A text summary of the maximum impact for all subcomponents is included. It also shows areas where winter weather is anticipated, but impacts are not expected to occur. The product combines meteorological forecast conditions with geographic and nonmeteorological factors to assess potential impacts. For example, the impacts of a snowstorm in southern states will have a higher impact than a similar storm in northern states.

Term edited 2 November 2022.

See numerical weather prediction, climate prediction;