Great Bend Tribune
Published October 18, 2020
The Drought Monitor shows all of Kansas at least abnormally dry with the western quarter of the state ranging from moderate to extreme drought. No great for wheat but it has allowed for a fairly rapid harvest. The six to ten-day outlook (October 20 to 24) indicates slightly above normal precipitation and well-below normal temperatures for this half of the state while Eastern Kansas should be closer to normal. Not great but not terrible for planting and establishing wheat. Looking out eight to fourteen days (October 22 to 28) indicates continued below-normal temperatures. Precipitation is below-normal for our half of Kansas and normal to slightly above normal for Eastern Kansas. And this leads to today’s topic, the 2020 La Nina.
Most have heard of the term El Nino, however, many are unaware of a La Nina. These weather events can have significant effects on the weather of much of the U.S., including Kansas. These events effecting our weather reflect the global nature of weather patterns, how events occurring across the world impact us here. So what is a La Nina?
A la Nina involves changes in the Pacific Ocean between the western Coast of South America and Indonesia in East Asia as does the El Nino pattern. These are cyclical but not necessarily regular. During a La Nina winter the winds blowing westward from South America are stronger than normal pushing more, warmer surface waters westward towards Indonesia. Under normal conditions this brings colder, deeper waters to the surface off the coast of Peru. Here, even more cold water comes up and causes the surfaces waters to cool a few more degrees than normal. Even this small changes impacts global weather.
This causes the area near Indonesia to receive more precipitation and South America less. And this cold water is carried up north towards the Pacific Coast of the U.S. This colder water causes the Southwest U.S., Great Plains and Southeast U.S. to be much drier than normal while the Pacific Northwest trends much wetter. For Kansas it trends towards a warmer winter also. For the Caribbean and Gulf Coasts, a developing La Nina leads to a very active hurricane season as we are indeed seeing this year.
This developing La Nina is forecasted to last through the winter and to be a moderate to strong event diminishing next spring. What does this mean for Kansas? Well, generally, as every La Nina is different in its impacts, we will be warmer than normal this winter and drier. It’s important to remember that November through January are typically are driest months with around one inch of precipitation each month. This presents a challenge for winter wheat, soil moisture for spring, and an increased fire danger. The extent will depend on how intense the event becomes.