Melting snowpack won’t help drought
Melting winter snowfall won’t do much to alleviate the extremely dry soil conditions across Minnesota, even if some areas experience spring flooding, said Greg Spoden, the state climatologist.
Roughly 70 percent of Minnesota is in extreme drought or severe drought. “All of the snow that has fallen over the winter by and large remains on top of the landscape, a landscape that is largely frozen,” he said. “Now the dust remains beneath the concrete.”
Despite winter precipitation that’s a little above average for much of the state and well above historic levels for parts of west-central and north-central Minnesota, soil moisture remains near all-time lows in much of the state.
Even flooding at this point won’t alleviate a drought.
The National Weather Service, which produces flood outlooks, has called for a high risk of flooding in the southern reaches of the Red River Valley, including the communities of Fargo-Moorhead and Wahpeton-Breckenridge in the late winter and early spring.
As the spring melt comes, the sun’s energy will be used to melt the snow first, rather than thaw out the ground. Water will flow over the land, leaving it drought-stricken once the waters subside. “First the snow has to leave before the soil unfreezes,” Spoden said. “So we can’t face a situation really where the soil will thaw and allow a significant infiltration of that snowpack.”
Abundant spring rain is needed to recharge the soil. The average March through May rainfall in Minnesota ranges from six to eight inches. “If we get at least that, we’ll be fine for the spring planting season,” Spoden said. “But to replenish those desperately dry subsoils, we’ll have to exceed that six- to eight-inch amount.”
The latest outlook from the Climate Prediction Center, a branch of the National Weather Service, calls for above average precipitation from March through May for the eastern half of Minnesota and for equal chances of above or below normal precipitation for the western half.
For more on the latest drought conditions: http://climate.umn.edu/doc/journal/drought_2013.htm.