National Weather Service proposes new five-level rainfall risk scale

The National Weather Service is seeking public feedback on a proposal to expand the Weather Prediction Center’s Excessive Rainfall Outlook from four risk levels to five. The proposed update introduces an "Enhanced" risk category, which would be positioned between the current "Slight" and "Moderate" levels.

The new five-level scale would consist of: Level 1 – Marginal (5%), Level 2 – Slight (15%), Level 3 – Enhanced (25%), Level 4 – Moderate (40%), and Level 5 – High (70%).

Officials stated that the addition of the "Enhanced" category aims to allow forecasters to communicate elevated threats of localized or regional flash flooding without necessarily escalating an area to a higher-impact Moderate Risk. The move is also intended to align the rainfall outlook with the Storm Prediction Center’s five-level scale used for severe thunderstorms and tornadoes, creating more consistent hazard graphics for emergency managers, broadcasters, and the public.