Effects of El Niño could be felt in Mid-South - WMC Action News 5 - Memphis, Tennessee

Effects of El Niño could be felt in Mid-South

Source: NOAA Source: NOAA

You’ve probably been hearing a lot about El Niño during the past few days. Several media outlets declared this year’s El Niño as a “Godzilla” one due to its intensity. Scientists at the Climate Prediction Center are estimating that this could be one of the strongest El Niño’s on record. But what is an El Niño and will it have an impact on the Mid-South?

Basic Information on El Niño

Normally, sea surface temperatures in the equatorial Pacific Ocean are warmest in the western Pacific and cooler on the eastern side. However, during an El Niño there are warmer than average ocean water temperatures in the Pacific Ocean at the equator. It’s still unknown exactly why this occurs, but this warming happens every few years and lasts for six months to over a year.

Source: NOAA 

Since thunderstorms require warm air near the surface, the atmosphere over the warmer ocean water typically has an increase in thunderstorm activity. So during an El Niño, there are usually more thunderstorms in the eastern Pacific Ocean. In addition, there is a weakening in strong winds near the equator during an El Niño, which are called trade winds. The combination of the weakening trade winds and change in atmospheric activity can cause a ripple effect that changes weather across the entire U.S.

Typical influences on the Mid-South

Since we see a shift of the southern jet stream further southward (the jets drive our weather patterns in the U.S.), an El Niño is expected to cause a cooler and drier winter in the Mid-South. However, that isn’t set in stone. An El Niño doesn’t ALWAYS result in certain weather impacts in the U.S., and these are just recorded trends during El Niño seasons. Being in the middle of the country, we could easily see a change in that typical pattern based on the location of the upper level wind flow (called the jet stream) further north or south. So, take the "cooler and drier" forecast with a grain of salt. It's a possibility for this Winter, but it's a forecast and NOT a definite outcome. 

Brittney Bryant
Follow me on Twitter @WX_BrittneyB
WMC Action News 5 Storm Tracking Team

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