Climate Change Future? Stuck, Dangerous Summer Weather Patterns And Southeast Hurricanes

A schematic of how Rossyby waves look as viewed from
above the North Pole. 

A prolonged, possibly record strong heat wave is starting in Europe about now, which is helping lead to more discussion about whether "stuck"summer weather patterns are increasing.

These "stuck" patterns can lead to more intense heat waves than previously felt, and more serious warm season flooding than previously experienced. And, of course, climate change might be behind this phenomenon.

Obviously, there's no way scientists can prove beyond a shadow of a doubt that the currently building European heat wave is "caused" by climate change. But it's consistent with what's been happening with growing frequency.

Possible examples include a deadly, summer long heat wave in Europe in 2003, and another long, fatal Russian heat wave in 2010. That same persistent weather pattern in 2010 fueled record flooding in Pakistan.

Other examples might include a 2011 Texas drought, floods across Europe in 2013, California wildfires in 2015 and 2018, and lengthy hot spells in Japan, Scandinavia, Quebec and northern New England last summer.

Climate scientists are looking at something called atmospheric  Rossby waves.  They're nothing new and totally normal. The Rossby waves help transfer heat from the tropics and cold air from the Arctic so that Earth's atmosphere can stay pretty balanced.

Rossby waves also help set in place the jet stream and lead to fairly long and persistent weather patterns.

These waves have always created "stuck" weather patterns, but with climate change, are Rossby waves somehow getting better at stalling weather patterns for longer periods of time? And making the "stuck" weather more intense?

There's usually about five to seven Rossby waves at any given time in the northern hemisphere, and they usually slowly move eastward. That's a big reason why you might get storminess for a few days, then dry and warm weather for a few days, then back to storminess.

However, it's possible that climate change might occasionally make the slow eastward motion of the Rossby waves to stop more often, setting up prolonged periods of heat under ridges in the waves, and long spells of heavy precipitation and flooding near the dips.

Large temperature constrasts between land and ocean might encourage Rossby waves to stall, and some climate models suggest these contrasts will get more extreme and more frequent, which would stall Rossby waves.

I know this is all weedy and technical, but it's one reason why climate scientists say the world isn't just warming up, but the weather is tending to get more extreme

SOUTHEAST HURRICANES

Often a big strong hurricane approaching the southeastern United States coast will weaken somewhat before getting to that region.

That's because hurricanes moving north from the tropics are likely to encounter wind shear. Wind shear is a change in wind direction and/or speed as you go up in elevation. Wind shear tends to tear hurricanes apart.

For people who live in the Southeast, that's a good thing. You'd want weaker hurricanes.

However, according to the Category 6 blog,  recent studies suggest that wind shear over the Southeastern United States during hurricane season will weaken over time, which would open the door for stronger hurricanes to hit the Southeast.

That even has implications for us up north. If the hurricane continues north, it might encounter wind shear later than it would have in a cooler climate, making the storm likely to be stronger as it got to New England.

On the bright side, the same study suggests climate change might increase wind shear in the deeper tropics, maybe making it less likely that strong hurricanes could develop in the first place.

Not all weird weather is attributable to climate change. There have always been oddball storms and record temperatures. However, climate change might be influencing these events. Like all picky details regarding climate change, this whole thing needs more study and review.