Study: More extreme weather events in the summers

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By: Charles Roop | WCTV Pinpoint Weather
November 2, 2018

TALLAHASSEE, Fla. (WCTV) -- Droughts and floods are an unfortunate weather phenomenon across the globe, but there is potential to see more of these in the summer months down the road.

Research released earlier this week said as the world warms, these jet streams could be more amplified and some of these patterns could persist a lot longer.

A jet stream is basically a stream of winds aloft in between really cold air and very warm air. The greater the thermal difference, the stronger the gradient and the stronger the winds in a jet stream.

But during the summer months, the positions of the jet stream’s troughs and ridges could be a bit more amplified. And these could be locked into place.

The authors looked into the “fingerprint” of the occurrence of these amplifications. They also referenced previous major weather events such as summer heat wave in Europe in 2003, the Russian heat wave and wildfires in 2010, and the drought and wildfires across Texas and Oklahoma in 2011. These events had similarities in temperature anomalies and wind fields.

They found that weaker midlatitude winds aloft with stronger winds in the subpolar and subtropical areas would set the stage for these amplification events.

And there is evidence to suggest that we could see these more down the road. On average, the authors found we could see 50 percent more of these amplifications this century and, therefore, a potential for more extreme weather events such as floods and droughts. The authors did find in their model runs that there is a possibility of tripling the number of events.

The authors did note one implication that a decrease in aerosols such as dust, volcanic ash, and smoke could lead to some lessening of the amplification in the first half of the 21st century. But an increasing global temperature could keep the frequency of the amplifications elevated, and make the amount of extreme weather events greater.