Nebraska is the new ground zero for the worst U.S. drought in nearly eight decades, and the drought is likely to persist into at least early 2013. Severe to extreme drought is spreading through the High Plains and worsening in Minnesota and parts of Iowa.
While no one has yet predicted the drought will linger into the 2013 planting season, no one has called an end to what has become a multi-year drought in large portions of the country either.
According to the National Oceanic and Atmospheric Administration’s (NOAA) Winter Outlook released Oct. 18, the western half of the country is expected to be warmer than normal in the December through February winter season, while Minnesota, Wisconsin, Iowa, northern Missouri, eastern North and South Dakota, Nebraska, Kansas, and western Illinois are expected to have drier-than normal conditions.
Drier-than-average conditions are also expected in the Pacific Northwest, Northern California, Idaho, western Montana, and portions of Wyoming, Utah, and most of Nevada.
"This is one of the most challenging outlooks we’ve produced in recent years because El Niño decided not to show up as expected," says Mike Halpert, deputy director of NOAA’s Climate Prediction Center. "In fact, it stalled out last month, leaving neutral conditions in place in the tropical Pacific." However, an El Niño watch remains in effect.
The latest U.S. Drought Monitor Index shows drought is worsening in Kansas, Nebraska, South Dakota, Minnesota, and Iowa, where conditions are rated mostly severe to exceptional.
The high-pressure ridge that set up over the country during the growing season, which was partly responsible for this summer’s drought in the heartland, is still there. "The high-pressure ridge has not been as persistent lately, but it is still part of the picture with what’s going on over the High Plains," says Mike Timlin, regional climatologist with the Midwest Regional Climate Center, Champaign, Illinois.
Fall rainfall and winter snowpack will be critical to the High Plains and a large portion of the Midwest. "Seventy-eight percent of Nebraska is in exceptional drought," says Natalie Umphlett, regional climatologist with the High Plains Regional Climate Center, Lincoln, Nebraska.
Soil moisture is definitely compromised across much of the country. In Nebraska, 72% of the topsoil and 80% of the subsoil are rated very short. Another hard-hit state, Kansas is doing better, but 30% of the state’s topsoil and 48% of the subsoil are rated very short, according to USDA.
In much of the Midwest, above-normal precipitation is also needed prior to next spring’s planting season. "The areas still in drought need a significant amount of moisture to replenish soil moisture," says TImlin.
Climatologists take three things into account when ranking droughts:
- peak of the drought
- length of the drought
- spatial advance of the drought