Some 45 million Americans are at risk of severe thunderstorms from Nebraska through parts of the Midwest and south-central states from Tuesday through Thursday.
The big picture: The National Weather Service's Storm Prediction Center issued an enhanced risk (level 3/5) of severe thunderstorms for parts of Iowa, northern Missouri and Illinois Tuesday.
Why it matters: It's the fourth global bleaching event on record, and the second in the last decade. Bleaching threatens the reefs, which are vital harbors for marine biodiversity and major drivers of fishing and tourism revenue for countries across the globe.
