The weather phenomenon El Niño may be on its way back. That’s after a weak La Niña system faded out a few months ago. Climatologist Brian Brettschneider said computer models are hinting at El Niño returning in the second half of this year.
“The models right now are predicting a 50 percent chance of an El Niño by this fall,” Brettschneider said.
But that doesn’t mean it’s a done deal, he says, but it’s something to keep a close eye on.
Brettschneider offered a primer for those who may have forgotten exactly what El Niño is and what causes it:
“There’s a lot of complicated interactions, but basically you have a warm pool of water that’s semi-permanent in the western Pacific and you have easterly trade winds that push that water and keep it over there. Those easterly trade winds weaken in an El Niño event and that warm water is able to slosh back into the central and eastern Pacific and that really affects a lot of the global circulation pattern because it facilitates thunderstorm development and the movement of air up, creating low pressure and then where that air has to settle back down, creating high pressure, so these large scale wind and pressure patterns that drive much of the climate of the globe.”
In Alaska, the effects of El Niño are most noticeable (and strong) in the winter, making conditions warmer than normal and usually a little wetter than normal.
The usual interval between El Niño years is around five years, but can range from over two to seven years. So, having another El Niño year after just a weak La Niña in between is not unheard of.
“There has been some research that shows in a warming world that El Niños and super El Niños will become more common,” Brettschneider said. “And the impacts of that will be felt more acutely, particularly in places like Alaska.”
Alaska’s Energy Desk is checking in with climatologist Brian Brettschneider each week as part of the segment, Ask a Climatologist. What do you want to ask?
Annie Feidt is the broadcast managing editor at Alaska Public Media. Reach her atafeidt@alaskapublic.org. Read more about Anniehere.
