El Nino Could Lead to a Tame Winter

After the brutal winter of 2013/2014; the dreaded Polar Vortex and record breaking lows, I'm sure many are looking for better news that this winter will be different.  Now that NOAA has released it's \"Winter Outlook\", there may be some hope in the months ahead. In this outlook, NOAA discusses the potential development of an El Niño. And while most of us have heard the term El Niño, what exactly is it, and how will it impact our weather this winter season?  In today's blog my goal is to help you understand the larger weather patterns that drive our weather for the season. The focal point for this upcoming winter is the El Niño. In short, El Niño is the warming of surface waters near the equatorial Pacific.  It's a phase of cycle known as the El Niño Southern Oscillation or (ENSO). This cycle shifts between warmer, neutral and colder than average surface water temperatures. When the waters in this region are warmer than normal, ENSO is in the El Niño phase; when the waters in the region are cooler than normal, ENSO is in the La Niña phase. Observing specific weather patterns that occur parallel to El Niño and La Niña events can help us forecast more long term weather patterns ahead.

Provided in this blog is a visual from the Climate Prediction Center, that gives you the big picture on the overall weather pattern here across the nation when an El Niño develops during our winter months. 

In the picture, you'll notice two separate branches of the jet stream; a Polar Jet and a Pacific Jet. Remember, the stream is a narrow channel of fast moving air found about 6 and a half miles above the Earth's surface. This channel of fast moving air forms at the boundaries of adjacent air masses with significant differences in temperature and serves as our storm track.  When an El Niño develops, the jet stream can appear split, like in the picture.  This split flow can provide a quieter, drier weather pattern here across Wisconsin. Why? Because neither jet stream is found right over southeast Wisconsin. Since the jets steer storms across the country, storms that build have the potential to flow north or south of the state. Plus, another benefit of a split flow jet stream is the coldest air will be locked north of that polar jet. That's not to say we won't at times see the jet buckle and send storms and cold blasts our way, but the overall winter may keep us in between the action.  Of course, weather is fluid so please check back here for updates as we head into the winter season!
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