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Well, it greatly affects global weather patterns, so it's very relevant when trying to understand a major cause of the recent cold spell over the Eastern half of North America.
Simply put, La Niña is the cooling sea surface temperatures in the central and eastern tropical Pacific Ocean below their average. This is measured when a positive phase of the El Niño Southern Oscillation is experienced for a period of 5 or more consecutive months, with temperature -0.5°C or more below average. This would be the opposite of perhaps the more widely known El Niño phenomena, where sea surface temperatures across the aforementioned region are, inversely, running above average.
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Seasonably cooler temps over the East, with warmer conditions across the West, are typically experienced in the winter months of La Niña years. That is exactly what we have witnessed, so we can't say this is winter, in concept, is that far gone from a normal La Niña pattern.
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But, this has been far from your typical La Niña winter. Weather patterns all over the world are becoming more pronounced, and the effects have been cataclysmic. Unfortunately, it appears that things will only get worse before they get better (more on this to come in future articles).
On a more personal note; you better buckle down America, because La Niña springs and summers heat up rapidly in the East, and tornadoes and hurricanes are often more frequent than average.
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2018 is already off to a wild start!!
Interesting, I didn't know this
We have been experiencing this for several years and it has been talked about in the news as well
Good info.