College News

Ag Instructor Vic Martin: La Nina and Kansas Winter

Great Bend Tribune
Published October 31, 2021

As of October 26, nothing had really changed regarding drought conditions as except for northeast Barton County, we aren’t even abnormally dry.  This doesn’t include the rains after Tuesday so some areas should have improved.   The six to ten-day outlook (November 2 to 6) indicates well-below normal temperatures (50% to 60% chance) and over ten degrees below normal and normal to above-normal precipitation (40% to 50% chance).  The eight to fourteen-day outlook (November 4 to 10) indicates normal to slightly below normal temperatures and the same for precipitation.  Also, there is a strong chance for a hard freeze early this week. 

NOAA has sent out a forecast for a La Nina this winter.  There are three patterns that can develop on the western coast of South America – normal, El Nino, and La Nina.  The El Nino typically results in wetter late fall and winter weather in Kansas while the weather tends to be warmer and milder.  However, the forecast is for a La Nina.  So what does that mean for this late fall and winter here?

First, just a little background helps with all this.  The weather off the coast of South America plays a significant role in the weather of the continental U.S. as there is an ocean current of the coast of the Americas the flows from south to north off the western coasts.  It actually starts with currents that flow from the western Pacific Ocean eastward to the coast of South America.  The events (El Nino or La Nina) can last for months or even over a year and while there is a pattern (typically every three to five years), it’s not hard and fast or exactly predictable.  These events can be strong or weak of while the effects are fairly predictable for many parts of the U.S., here in Kansas we are kind of in between so it depends on the intensity of the event.

While an El Nino results in warmer waters and weaker east winds, the La Nino results in cooler waters and stronger east winds.  This has dramatic effects on typical winter weather patterns as places like the Pacific Northwest tend to be wetter and cooler than normal and the Southwest drier.  Often a La Nina results in increased hurricane activity.  For us in Kansas, the prediction is for about a 40% chance of above-normal temperatures and equal chances of above or below normal precipitation.  Often drier conditions go along with the warmer temperatures so the forecast is for drought conditions to intensify, especially in the western part of the state.  Remember that on average, the driest part of our year out here is November through February where the amount of liquid precipitation is only around an inch.  So warmer temperatures aren’t beneficial for the wheat crop.  They also favor more overwintering insects and the early emergence of pests like cutworm which combine with stressed wheat creates problems.