KVRR Chief Meteorologist Rob Kupec’s Details Behind the Winter Weather Outlook

REGIONAL — Is this the start of a long and brutal winter? Or will it be like a little bump in what has been a couple of low snow mild years?

All signs are pointing to a La Nina forming in the southern Pacific.

Just what is a La Nina? Here’s a breakdown:

There are a bend of winds along the equator that blow to the west, known as the Trade Winds. They tend to push warm water to the western Pacific. During a La Nina, the winds are even stronger and the warm water is pushed even further west. This allows cold water to the surface in the eastern Pacific.

So how does this impact us?

It tends to push the jet stream further north and allows cooler air to drop into the north central U.S. But not all La Nina are cold, and what about snow? Last winter was a La Nina winter, and we had well under our average amount of snow in Fargo. Remember, the La Nina winters tend to be cool. Last winter, Fargo was 5.6 degrees above average.

So what other factors influence this?

Many of our storms and weather over all come from the northern Pacific. Last year, that water was warmer. This fall, there are signs of a cooling trend. In the arctic ocean, sea ice was at nearly an all time minimum, especially north of Alaska, last October. This October, it’s already covering more of the ocean. That open ocean last year moderated temperatures and influenced the placement of the Jet Stream.

Out in the Atlantic, there is something called the North Atlantic Oscillation, which deals with ares of low and high pressure. Last year, there was what is called the Positive Phase, which allows the jet stream to move clearly across the ocean to Europe and keeps cold air locked over Greenland. This year, it appears we are entering a Negative Phase, which allows warm air to move up over Greenland and displaces cold air in our direction. The jet stream also become more amplified or wavier making more wild swings in temperature across parts of North America.

So what does all this mean?

The Winter Temperature Outlook, from the Climate Prediction Center, shows a good chance of below average temperatures, which Rob agrees with.

For Precipitation, they have a good chance of this area seeing above average precipitation for the winter and here, Rob says he many quibble with them a little. For the winter months of December through February, Rob says he thinks Fargo’s average temperature will run two degrees below average. For snowfall for the season, which means from today with our first snow until the end of spring, he is forecasting 48 inches of snow, which is just below our average of 50.

Rob says he thinks we are in a little bit of a drier trend now, and that we will see more snow than the last few years but still come in below average.