November 5, 2015: El Niño will be talked about A LOT this winter. This is a climate pattern that occurs fairly regularly, or every few years. We typically see the El Niño impact the winter months the most, as it starts in the spring or summer in the Northern Hemisphere, then intensifies through the fall, peaks in the winter, then falls back down again.
So what is it? We start in the Pacific Ocean, near the Equator. Usually, the air flow, or trade winds, goes from east to west across the Ocean. These winds are able to push and pile up a lot of warm water in the Western Pacific, near Australia and Thailand.
During El Niño, those trade winds across the Pacific relax, causing the eastern Pacific near South America to be warm instead. These warm waters are able to influence the jet stream patterns across the globe, having impressive impacts close to home, despite being 4000 miles away.
The altered jet streams bring colder, very rainy weather to California (enough rain to cause plenty of mudslides) and the Deep South, which warm and drier weather settles into the Midwest.
How much warmer and drier depends on the strength of the El Niño, in addition to how strong other weather patterns are and whether they can “trump” the El Niño. This year, we may have our first strong El Niño, the first since 1997. The most recent strong El Niño’s, the 1997 and 1982 events, brought top ten warmest winters (4th and 7th, respectively) and 10″ to 15″ less snow than usual. The 2015 El Niño is still on track to be within the ball park of those two, which are the strongest on record.
Once we get beyond the winter, we typically see a cool-to-average spring, then possibly a hot summer. This is as El Niño fizzles out, and the waters and trade winds in the Pacific go back to normal.
Where did the name “El Niño” come from, anyway? Fishermen in South America picked up on the occasional very warm waters, usually arriving around Christmas time. El Niño means “the Christ child”, in honor of the Christmas season when these warm waters arrived.
You may have heard of the opposite to El Niño, known as La Niña (which means “the little girl”, as an opposite). La Niña is typically a “cold event”, when much colder water pools near South America. La Niña generally pushed much colder air in to the Midwest, causing a long, cold winter for us.
Stay tuned; the next blog post or two will be more about this upcoming winter, plus we will be bringing this subject back up and comparing the results to this forecast as we go along in the winter months.
Check out www.wrex.com for our special report on El Niño, plus watch an extended interview with Dr. David Chagnon of Northern Illinois University about the climate pattern.
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