Iowa Public Television

 

Flash Drought Zaps Moisture Out of Corn Belt

posted on September 6, 2013


The U.S. Forest Service says the 300 square mile Rim Fire, one of the largest forest fires in California history, is 80 percent contained. A hunter who - at one point - was linked to the illegal marijuana industry is being questioned about his role in starting the fire that has cost $81 million to fight.

The drought that preceded the fire that burned an area larger than the city of Chicago was just one stage of a weather cycle that stretches back nearly 100 years.  The same weather patterns have been affecting farm country for centuries. And one climatologist, who has been consulting the historical record, says this is nothing new. Paul Yeager explains.

The year *after* the worst drought in half a century began with a series of rain showers that lasted well into spring planting season. The dramatic change in weather patterns replenished subsoil moisture that had been zapped out the year before. Snowfall in early May added insult to injury in the Corn Belt, delaying planting even further.

But for some producers, that flood of moisture evaporated in what seemed like a matter of days.  

Last week, the Drought Monitor declared a “flash drought” for portions of the Corn Belt. Those same locations set records for the wettest springs, only to experience a turning of the tables to the driest summer ever.

But one noted climatologist questions the validity of the term “flash drought.”   

Elwynn Taylor, Iowa State University Extension: “it is a little bit hard to define, because I think someone made the term up, from flash floods. I don’t think we have a flash drought but people are talking about it right now because suddenly Iowa in drought and have been in floods this spring.”

Elwynn Taylor is a climatologist for Iowa State University’s Extension service. Taylor interprets weather patterns of the past to try and predict what may happen in the future.

This season’s volatile swing in precipitation was paired with a wide spread in temperatures. A cold and wet spring was replaced with a hot and dry summer as several locations in Iowa set records in August for dryness. According to climatologists, the region from the eastern Dakotas through Minnesota and into Wisconsin, experienced rainfall last month anywhere from 5 to 25 percent below normal. Add in excessive heat, crops and pastureland conditions have quickly deteriorated.

Elwynn Taylor, Iowa State University Extension:”You can remind people who are not old enough to remember 1936 that was the coldest winter of the century, followed by the hottest summer of the century. Often, the extremes both ways go together. The winter was not just cold, it was wet. Summer was not just hot, it was dry.”

Earlier this summer, Taylor presented data comparing 2013’s pattern to 1947.

The historical records show a late July heat wave lasted until early September. This year’s blast of hot weather didn’t hit full blast until late August, but still baked corn already on life-support from a shallow root system.

Back in 1947, an isolated early frost hit some Iowa farmers. But the first hard freeze came well after the state’s average of mid-October.

Elwynn Taylor, Iowa State University Extension: “Dry and excessive heat, the combination of the two, added up that it became one of the three worst years of history of corn yields in the Midwest.“

The Drought Monitor from the University of Nebraska has shown consistent drying the last few weeks across the Corn Belt states of Minnesota, Iowa, Wisconsin, Illinois and now into Indiana.  

The hit and miss rainfall over the northern Plains and upper Midwest is helping expand the drought conditions in that area.

In the Midwest, well above-normal temperatures, in some cases, 6 to ten degrees higher, a continued lack of rain and near-record low August rainfall in a few areas has led to rapidly declining topsoil moisture which is evident in corn and soybean fields.

Elwynn Taylor, Iowa State University Extension:”The third day of temperatures over 94, was the day the damage really began. Significant yield was lost in places where they had temperatures over 94 those days.”

Overall this week, 50.09 percent of the contiguous U.S. is in some form of drought, a slight increase in intensity over last week.

Is this a short-term or long-term pattern? The one thing we know, Taylor adds, is the only consistent thing now is inconsistency.

Elwynn Taylor, Iowa State University Extension: “During the next few years, we expect to see more of those kind of conditions that we saw in the 70s and 80s because we are past the consistent 18 years of consistent yields now and into the 25 year period, it appears, of greater volatility of weather and a greater need for the management of risk in agriculture and everything that is agriculatural-dependent. And I would expect the next 25 years if we’re going this century to have a Dust Bowl-like weather condition, it will be around 2025. These periods seem to be 89 years apart, the Dust Bowl-like conditions of the 1800s in Iowa, 1847, 1936, and if things continue as they done for the last 300-400 years, 2025. Plus or minus a couple of years.”

For Market to Market, I’m Paul Yeager.


Tags: climatologist corn Corn Belt drought Drought Monitor Dust Bowl Elwynn Taylor Flash Drought ISU Extension news precipitation soybeans volatility weather