It turns out even weather maps aren’t safe from the wrath of Harvey’s rainfall. The National Weather Service had to add colors to its mapping system in order to track rain in southeastern Texas. The agency says this move gives “perspective” to how much rainfall the state is experiencing. “So much rain has fallen, we’ve had to update the color charts on our graphics in order to effectively map it.”
Previously the map’s 13 colors topped out at rainfall over 15″, but the new scale resets the darkest purple shade to 15″-20″ while adding two more markers: 20″-30″ and greater than 30″. The new hues are depicted by lighter purples.