Despite torrential weekend rains in southern Minnesota, a wide swath of central and northeastern Minnesota received little precipitation and remains in extreme drought, a new federal report said Thursday.

The areas that benefited from the rain were across south-central and southwestern Minnesota, where more than 4 inches of rain fell over several days and did not cause the off-the-charts flooding that battered southeastern counties.

"In the past 200 years I can't find another point in time when Minnesota's landscape was exhibiting this range of hydrological extremes," said Mark Seeley, University of Minnesota Extension climatologist and meteorologist. Southeastern Minnesota has received more than 20 inches of rain in some areas this month, he said, while places such as Hibbing in the northeast have received only three-hundredths of an inch.

Last week's rains were beneficial in areas such as Waseca, said Gyles Randall, soil scientist and professor at the University of Minnesota's Southern Research and Outreach Center.

"I saw a lot of smiles on farmers' faces about a week ago from all over south-central Minnesota because rain was coming," Randall said.

The precipitation may have been too late to maximize corn yields, he said, but the rains kept those yields from deteriorating further. The rain probably arrived in time to generate additional growth for soybeans, he said, but those gains could be slowed somewhat unless sunnier and warmer weather follows soon.

Largely missed by the rains are counties in central Minnesota north and west of Willmar and near Mille Lacs Lake where the drought continues to be extreme. Those areas received 1 to 2 inches of rain during the past eight days that ended Tuesday, according to Greg Spoden, climatologist for the Minnesota Department of Natural Resources, but not nearly enough to make a significant difference. Much more rain will be needed to replenish moisture in the topsoil, he said.

Moisture levels during this summer's growing season have been like a checking account, Spoden said. "There has been a lot of withdrawals and almost no deposits," in many areas, he said.

'Some semblance of average'

Better estimates of how corn and soybeans will be affected by the latest weather are expected next Monday, when the U.S. Department of Agriculture will publish its next crop-weather report. Last week's version before the rain estimated that 36 percent of the state's corn crop was in poor or very poor condition and that 25 percent of the soybeans were in those categories.

Seeley said that one bright spot of the past week is that dairy farmers may now see some relief in the cost of high-quality alfalfa hay that they feed to cows. The rains will probably allow another hay crop to be harvested this season in south-central Minnesota, he said, which should increase supplies and decrease prices considerably.

Spoden said that the rain will also have a positive effect on the 2008 growing season.

"Even rain that falls now will be welcome for next year," he said, and last week's precipitation brought many areas in southern Minnesota from soil moisture deficits to "some semblance of average."

As heavy as the rain was, he said, it fell gradually and replenished soil moisture without forming ponds, causing erosion or creating flash floods as it did in southeastern counties.

However, areas with extreme drought conditions also will carry that into 2008 if they don't receive abundant rainfall this autumn, Seeley said. "Otherwise they'll be all set for a repeat of last spring with extremely low stream flows, restricted lake access, high fire danger, and stressed forests and vegetation," he said.

Tom Meersman • 612-673-7388

Tom Meersman • meersman@startribune.com