Another day, same droughtPublished 9:39am Friday, October 5, 2012
As one of the driest Septembers in state history comes to an end, the drought situation in Minnesota is being assessed by a number of state agencies as well as the University of Minnesota Extension.
The fall season is a critical hydrological recharge period for the state in terms of soil moisture, lakes and streams. Usually a very high percentage of the rainfall and snowfall is utilized by the landscape and little runs off during October, November and December, according to Mark Seeley, a University of Minnesota climatologist. It’s critical for the overall health of the soil and water resources that adequate or surplus precipitation falls before the landscape freezes for the winter.
Though early growing-season rainfall was at a surplus during April, May and June, the drought’s imprint on the state has expanded since July. Severe or extreme drought as designated by the U.S. Drought Monitor is now prevalent in 45 Minnesota counties, most notably southwestern, south-central and northwestern agricultural landscapes.
Since mid-July, many counties reported less than half of normal rainfall, while some areas also reported a record-setting, dry September. In addition, stored soil moisture are now showing near-record or record low values for the end of September.
Other signs of extreme dryness include lake levels drastically down and flow volume on many Minnesota watersheds below the 10th percentile historically for this time of year. The danger of wild fires is very high in many areas of the state, too. Overall, the state has not seen this area and severity of drought since the fall of 2006, according to Seeley.
At this point, the additional precipitation needed to alleviate drought in most of the counties currently affected ranges from 6 to 12 inches. This is highly improbable considering that all-time record amounts of precipitation would be needed by December.
A more realistic expectation, Seeley says, is that enough precipitation will fall before the end of the year that there will be some modest alleviation to the soil moisture deficits. A wet spring is needed for a decent 2013 crop in Minnesota.
Visit www.extension.umn.edu/drought for drought-related educational information, and climate.umn.edu for more information from the University of Minnesota’s climatology working group.