The drought that has gripped the central United States for the past two years is holding on tight, federal forecasters said yesterday. Almost 59 percent of the contiguous United States is experiencing drought, according to the latest U.S. Drought Monitor update, with the worst conditions concentrated in the Great Plains and Western states.

The final, most accurate tally of 2012 crop production to date was released Friday by the Agriculture Department, confirming the extent of crop losses due to the drought. Corn production topped at 10.8 billion bushels, about 55 million bushels more than last month's estimate, but still 13 percent lower than last year and more than a quarter less than what USDA expected in May.

Lake Michigan's water levels have plunged in recent months as the nation continues to experience record drought conditions, creating a scenario that could allow the Chicago River to flow backward into the lake. The Army Corps of Engineers, which manages a set of locks between the lake and the Chicago River, typically keeps the lake's water level 6 inches higher than the river, but the ongoing drought has caused the lake's level to dip to its lowest point since 1964.