Our Daily Planet: Kentucky Derby Weather Odds and Memphis Flood Evacuations

Each weekday morning, OurAmazingPlanet takes the pulse of the Earth, reporting on natural phenomena and exploration news from around the globe.

Memphis Flooding: The Mississippi River has spilled over into downtown Memphis, where authorities are going door to door to ask people to leave. [Countdown: Mightiest Floods of the Mississippi River. ]

Flood Threat Moves South: The historic Mississippi River flooding has spread all the way to the Mississippi delta. [Related: What's Behind the Record Mississippi River Flooding? ]

EF-5 Number Three: The tornado that hit Hackleburg, Ala., has been rated an EF-5 on the tornado damage scale, the highest rating and the third EF-5 from last week's outbreak. [Related: The Tornado Damage Scale In Images ]

Many Still Missing: In Alabama, dozens of people remain missing after the historic tornado outbreak that struck one week ago.

Kentucky Derby Forecast: Rain and thunderstorms could make for a muddy race at Churchill Downs on Saturday. Could it be the coldest derby ever?

Previously on Our Daily Planet: Mississippi River Flooding and Throat of Fire Eruption Photos

Reach OurAmazingPlanet staff writer Brett Israel at bisrael@techmedianetwork.com. Follow him on Twitter @btisrael.

Brett Israel was a staff writer for Live Science with a focus on environmental issues. He holds a bachelor’s degree in biochemistry and molecular biology from The University of Georgia, a master’s degree in journalism from New York University, and has studied doctorate-level biochemistry at Emory University.