CHICAGO (Reuters) - A historic drought that has gripped the southern Plains for months intensified in the last week, while "abnormally dry" conditions emerged in parts of the Midwest, according to a weekly report issued Thursday by U.S. climatologists.
But significant rains brought relief to the Gulf Coast, easing drought conditions there.
Texas remained the epicenter of the crisis, with "exceptional drought," the most severe drought category, covering 75 percent of the state -- the most in at least a decade and up from nearly 72 percent last week.
Drought conditions persisted with little change in Oklahoma, where three-quarters of the state was classified as in a severe drought, and Kansas, where nearly half the state was in a moderate drought.
In the Midwest, where temperatures topped 100 degrees Fahrenheit (38 Celsius) this week, threatening developing corn and soy crops, the report showed abnormally dry conditions emerging.
The problem areas, encompassing about 10 percent of the region, included the northern quarter of Illinois, part of east-central Iowa and southern Wisconsin, northeast Indiana, northwest Indiana and southeast Michigan.
The Midwest drying trend represents a remarkable shift from this spring, when persistent rains slowed planting in many parts of the Corn Belt.
Climatologists said the drying trend in the region began 60 days ago. Precipitation during the last 30 days has been less than half of normal for many portions of eastern Iowa, northern Illinois, and Indiana, the weekly report said.
Along the Gulf Coast, significant rains fell in the last week across Alabama, Mississippi, Louisiana and the Florida Panhandle, resulting in significant improvements in the drought designation.
But 12-month rainfall deficits range from 16 inches to more than 20 inches below average across the region, the report said.
(Reporting by Julie Ingwersen; editing by Jim Marshall)
(Link to U.S. Drought Monitor map: http://www.drought.unl.edu/dm/monitor.html)