La Nina conditions are expected to play a big role in our winter and spring forecast.
According to the National Weather Service’s Climate Prediction center, this year’s winter favors a La Nina pattern by 95%. By this spring, La Nina is expected to weaken, but still is favored by 65%.
Now, what is a La Nina? Simply put, it’s when sea surface temperatures in the Eastern Pacific are at least 0.5 degrees Celsius (0.9 degrees Fahrenheit) below normal.
An El Nino pattern is the opposite and when water temperatures near the equator are above normal. There have even been signs that this winter could favor a strong La Nino, which means that water temperatures are closer to 1.5 degrees Celsius below normal.
Another big weather feature during a La Nina winter is a blocking area of high pressure building in the Pacific just south of Alaska. This initially rises the jet stream, then bring it plunging down around the United States and Canada border.
As a result, a La Nina Winter will bring Colder than normal temperatures to northern states, then a warmer than normal temperature trend in the southern half of the country.
This change in the jet stream also rises the traditional storm track. As a result, areas like the Ohio Valley are in line for wetter than normal conditions.
So, here in Central Ohio, we are on track for a winter that’s warmer and wetter than normal.