El Nio is here! What does it mean for the High Plains?

If you have been following El Niño news, then you know that there has been a possibility for the development of El Niño conditions for the past several months. The latest observations show that El Niño conditions have finally developed, so as a result, the National Oceanic and Atmospheric Administration (NOAA) has upgraded the status of El Niño from “El Niño Watch” to “El Niño Advisory.”

What conditions have changed to bring about El Niño? For several months, sea surface temperatures (SSTs) have been above normal in the equatorial Pacific region, which is one indicator of the presence of El Niño. The atmosphere must respond to above normal SSTs, however, and this has not happened until just recently. Recent changes in patterns of rainfall, wind, and atmospheric circulation in the equatorial Pacific are all now indicative of El Niño conditions.

So what does this mean for the High Plains region? Historical March-May precipitation patterns during El Niño conditions indicate that during some El Niño years, below average precipitation has occurred in western and central Wyoming, northern Colorado, and eastern South Dakota, while above average precipitation has occurred in southern Nebraska and northern Kansas (see graphic above). Impacts from El Niño are generally not very strong during the spring season, however, and the developing El Niño is very weak, so precipitation patterns in the High Plains region may not be strongly affected by El Niño at this time. El Niño conditions are expected to continue through the fall, and updates will be provided if conditions change.

For more information on this developing El Niño, please see NOAA’s news release, which can be found here: http://www.climate.gov/news-features/blogs/enso/march-2015-enso-discussion-el-ni%C3%B1o-here