Have you noticed that it has been unseasonably warm for weeks at a time, and then unseasonably cold for weeks at a time? Well, that is all to do with La Niña. What is La Niña? La Niña is a type of weather pattern in the Pacific Ocean that is affected by the ocean temperatures. It means “little girl” in Spanish.
The system alternates from El Nino, what we had last year, to La Niña, what we have now, about every two years. La Nino is the exact opposite of La Niña, where it makes the air much warmer than usual. Last year we had a very little amount of snow because of El Nino. Last year was a “super” El Nino resulting in the warmest winter on record. This year, we already have 7.5 inches of snowfall as of Jan. 13.
During La Niña, trade winds in the Pacific Ocean are even stronger than usual, bringing cold, nutrient-rich water to the surface. These cold waters in the Pacific push the jet stream northward. This tends to lead to drought in the southern U.S. and heavy rains and flooding in the Pacific Northwest and Canada. During a La Niña year, winter temperatures are warmer than normal in the south and cooler than normal in the north. La Niña can also lead to a more severe hurricane season. This means that generally, we will have cooler average temperatures than normal here in PA, but when the winds are blowing from the warmer-than-usual south, we will have warmer weather. And so the cycle continues.
With the drier and warmer south, it can fuel fires like the Los Angeles fires. The Los Angeles fires have already ripped through 1,400 homes. Because LA is in the south, it usually gets warmer weather from La Niña, and gets less rain, making wildfires more likely.
But what does that mean for us? Well, we are in the colder half of the US, and in a part that generally gets more precipitation during La Niña. This means that we should get more snow this year, more delays, and FID-Days. We have already had one snow day this year after a big snow overnight, and two FID-Days during temperatures of -12°F in the mornings and overnight.
