Iowa Public Television


Second Strongest La Nina Continues

posted on February 3, 2012

As weather conditions pressure cattle producers to reduce herd size, grain farmers in the Midwest and high plains are watching Mother Nature with some concern.  The drought that has gripped parts of the Southwest for the better part of a year just won’t let go.

With rainfall lower than expected and snowpack at some of the lowest levels in years, farmers in rural America are wondering if dry conditions will creep northward. While climatologists disagree on this year’s forecast, one weather expert is looking back through history for answers.

Second Strongest La Nina Continues

The second strongest La Nina, now entering its third calendar year of existence, continues its grip on the western Corn Belt.

Some analysts see a 60 percent chance of a changing weather pattern ending shortly after corn and soybeans are planted. But Iowa State University Extension Climatologist Elwynn Taylor is not convinced the abnormally dry conditions in the Midwest are over.

La Nina puts high and low pressure systems opposite each other on the equator, impacting weather all over the planet.

Elwynn Taylor/Iowa State University Extension Climatologist: “If we get high pressure and low pressure in different places, some places will be wet, some places will be dry. It tends to be during winter that the Corn Belt, during the La Nina, is dry for the winter in the western half, and sopping wet in Ohio River valley.”

Taylor says this is part of the reason portions of Alaska have seen abnormally high snowfall this winter. And any evidence of snow is hard to find on the farm fields of Iowa or in other Corn Belt states.

Taylor says three factors are in play for much of the country’s weather pattern.

Elwynn Taylor/Iowa State University Extension Climatologist: “The La Nina and El Nino event, is one of them, an important one, the Pacific decadal oscillation, the conditions between Hawaii and Alaska, is the second. And the third one is what happens on the East Coast, with the North Atlantic oscillation which is responsible for giving us a tendency for rougher or milder winters depending on what phase it is in.”

Tile lines are dry, creeks low, river beds exposed. The pattern is similar to the last major drought to impact the Midwest in 1988.

Elwynn Taylor/Iowa State University Extension Climatologist: “We are set up for it to happen, but that doesn’t mean that it will. We hope the setup dies out before it become crucial, but it is the same set up right now, four months earlier on the calendar.”

 The University of Nebraska Lincoln’s Drought Monitor shows continued extreme dry conditions in New Mexico through Texas to the southeast. Much of this region baked under extreme heat in 2011 as little rain fell, and now, may serve as an indicator for the Corn Belt.

Elwynn Taylor/Iowa State University Extension Climatologist: “The drought in the southeast that we didn’t hear much about last year, is still very real, they have a habit of still being there in the beginning of the second year. 16 of the past 17 major droughts started in the Carolinas and then expanded into the Corn Belt, that then becomes a statistical risk for 2012 of what was in Carolina moving into the Corn Belt this year.”


Tags: agriculture drought El Nino La Nina moisture news pattern Storm weather