Climate Central: On Wednesday, the U.S. Department of Agriculture (USDA) declared 597 counties across 14 states natural disaster areas as a result of the ongoing drought that threatens the winter wheat crop. These are the first drought-related natural disaster declarations of the year, and mark the second year in a row that such measures were necessary due to the drought event, which is the worst such event since the 1950s. Overall drought impacts across the continental U.S. improved slightly this week, due to mild...