Black outlines on the map mark areas where severe weather is possible. A severe thunderstorm is defined as meeting one or more of the following:
The latest automated guidance or client-side ensemble for the selected valid day will appear here.
When automated runs exist for the selected valid day, the ensemble is blended in the browser immediately.
HOCO polygons use a lightning-probability scale rather than the manual `1` to `5` convective risk categories.
