New York & Pennsylvania (WETM) – A La Niña winter is predicted for the third consecutive year in a row but what exactly does that mean for the Twin Tiers?

For three years in a row now, we have had a La Niña pattern for winter. What exactly is La Niña though? 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 Niña events, these trade winds are stronger than normal which pushes warm water near the equator to the west and results in upwelling of colder water. This is why the sea surface temperatures end up lower near the equator during La Niña 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 streams position, 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. The outlook for temperature and precipitation this winter both favor the potential to be above normal. 

Last year was a La Niña year and snow accumulation was below average by about 4 inches in Elmira. Two years ago was also a La Niña year and was an above average year snowfall wise with us being about 4 inches above normal 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.