The map showing areas gripped by the months-long U.S. drought shrank slightly this week, although some of the hardest-hit areas saw conditions worsen.

More than half the country -- 52.2 percent -- is still snarled by drought, according to the U.S. Drought Monitor map released this morning. A powerful storm brought rains to the West, shrinking the total amount of territory in drought. But parched conditions elsewhere caused the amount of land categorized as being in severe, extreme and exceptional drought to inch upward.

Mississippi River flows continued to decline this week, the Drought Monitor's summary said. Barge operators fear the river may have to be closed to shipping traffic, and have asked the Army Corps of Engineers to release water from the Missouri River, riling farmers who rely on that water for irrigation (Greenwire, Dec. 5).

Meanwhile, the corps is undertaking blasting and dredging operations to remove rock formations in a bid to keep the river navigable amid low water conditions (Greenwire, Dec. 4).

The drought is also continuing to affect crops in the nation's heartland. Department of Agriculture economist Brad Rippey said winter wheat conditions this year are the worst on record since data were first collected in 1986.

The proportion of the U.S. hay crop in drought is 65 percent, up 5 percentage points from Nov. 13. The proportion of cattle in drought is up 4 points from the same date, now at 73 percent.