The effect of modifying the Storm Prediction Center Convective Outlook scale on perceived risk level

The National Weather Service Storm Prediction Center Convective Outlook (CO) is a flagship probability‐derived forecast product in the United States (US). Although much attention has been devoted to how the terminology and risk category labels and colours in the CO are ordered, no study has yet to evaluate how end‐user risk perception is affected by switching the colour scales from discrete to continuous. Results from an online survey of 1409 US adults show that perceived level of risk increases when the colour scale is modified from discrete to continuous, even if the underlying forecast data do not change.