Drought spreads over Minnesota, dry fall forecast

  • Article by: BILL McAULIFFE
  • Star Tribune
  • September 17, 2012 - 6:35 AM

Although Minnesota escaped the worst of this summer's blistering U.S. drought, dry conditions have spread across the state in recent weeks and aren't expected to ease soon.

The U.S. Drought Monitor last week identified a band of central Minnesota, including the northern half of the metro area, as experiencing moderate drought. That put 44 percent of the state in some kind of drought status, up slightly from the previous week. Two tongues of southern Minnesota are in extreme drought.

Meanwhile, the national Climate Prediction Center sees a strong trend toward lower-than-normal precipitation across virtually all of Minnesota for the rest of September. Through Friday, only .11 inch of rain had fallen this month at Minneapolis-St. Paul International Airport. If that pace continues, this will be the driest September on record.

The second-driest occurred only a year ago, on the way to an odd sequence of an extremely dry fall and winter followed by the Twin Cities' second-wettest May on record and torrents of rain in northeast and southeast Minnesota in mid-June.

'Flash drought'

Since August began, most of Minnesota has received less than 3 inches of rain; central Minnesota, including much of the metro, less than 2. At the Southern Research and Outreach Center in Waseca, soil moisture is the lowest it's been since the drought of 1988. Minnesota state climatologist Greg Spoden called it a "flash drought."

"We had 14 1/2 inches of rain in May. You'd have figured we had enough rain to last forever a that point," said Steve Eid, owner of Steve's Elk River Nursery, in the heart of the newly designated drought area. "But you're really seeing [drought] in the lawns and especially the shade trees right now. They're dropping leaves sooner than they should. I don't see where we're going to have a lot of good fall color because of the stress you see in the trees."

Declining river flows and decreases in other water levels have prompted the Minnesota Department of Natural Resources to suspend or restrict surface-water use permits to businesses, golf courses, parks departments and others in various parts of the state. The agency told 16 users, from Moorhead-based American Crystal Sugar to a U.S. Fish and Wildlife Service project in southeast Minnesota, that their water withdrawals were being suspended until conditions improve. Some permits were suspended during last fall's dry weather; 350 were suspended in the epic drought years of 1988 and 1989, according to Greg Kruse, supervisor of the DNR's water-monitoring and surveys unit. American Crystal Sugar spokesman Jeff Schweitzer said the permits were for backup plans the company hasn't been using, so the suspensions will not affect operations.

The relatively quick and late-season onset of drought conditions may have had some benefits. Unlike other farmers across the central United States, Minnesota farmers were able not just to dodge major crop losses but to actually score some wins. Sugar beet farmers might harvest a record crop and corn production may be up 7 percent. The beet crop got well-established early in the season, said American Crystal Sugar's Schweitzer; the beets, as a root crop, were able to draw moisture from the soil via a long taproot even as soils dried out.

Meanwhile, low river levels are giving the U.S. Geological Survey (USGS) an opportunity to study how urban development along Interstate 94 affects the flow of the Mississippi River between the Twin Cities and St. Cloud.

Rivers in the region are now flowing with only clear groundwater that has seeped into them, said Jim Stark, director of the USGS Minnesota Water Science Center. As a result, the agency can measure how well-water use in cities along that corridor is affecting the Mississippi's base flow rate. The two-year study began this spring.

"It's fortuitous," Stark said of the low water. "It's really helpful to have it early on."

The dry season

While dry weather in late summer and early fall also makes crop harvesting easier and cheaper, rain that falls after crops stop growing provides moisture to start things growing next spring, Spoden noted. But the chances of such "rescue rains" diminish as autumn wears on, he said.

The continuing dry conditions also have posed fire risks across Minnesota. As of Friday, fire danger in the northern two-thirds of Minnesota was rated high or very high. In the south, where the fire danger is rated moderate, the risk in the coming weeks will be fires started by combines working in the fields, said Tom Hoverstad, a scientist at the research center in Waseca.

"Combine fires are a real danger in farming," he said.

Bill McAuliffe • 612-673-7646

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