New York (WETM) – A La Niña winter is predicted but what exactly does that mean for New York state?

Let me first start off by explaining what La Nina is. It is a cooling event of the water in the equatorial region. This cooling is due to trade winds which blow from east to west. During La Nina events, these trade winds push warm water near the equator to the west which results in upwelling of colder water. This is why the sea surface temperatures end up lower near the equator during La Nina events.

Of course, there are repercussions for this cooler ocean water. The jet stream which acts as our steering pattern for weather systems gets shifted north. A temperature gradient really dictates the jet stream, and it is pushed farther north due to the change in the temperature gradient from the north pole to the equator. This is a result of water cooling in the equatorial region. A northward jet stream has impacts on our winter. Remember, the jet stream acts as a steering current for weather systems, so the shape of it will help bring more weather systems into our area this winter. This will result in higher precipitation totals. 

Also, with the shape of the jet stream, it digs southward at a specific point which helps usher in warmer air into the north. Above average temperatures result due to this northward push of warmer air from the south. NOAA, the National Oceanic and Atmospheric Administration, has just that for their winter outlook. 

Last year was a La Nina year and was an above average year snowfall wise with us being about 4 inches above normal here in Elmira. As for temperatures, 30 days last winter were above average temperature wise here in Elmira. For this winter in New York, it is looking like an above average precipitation and temperature year. I hope this helped explain why this winter is expected to be the way it is.