The national winter forecast has been out for several weeks, but it has been a general estimate of projected winter weather impacts. 3 News Now Weather Alert Team Meteorologist Ryan McPike and I have been monitoring La Niña and additional current trends, and we've developed our own forecast for the winter season.
This winter is going to be colder than last year but still slightly above average. We will see some temperature swings going from below normal to above normal in a matter days, which is a trend we’ve actually been experiencing for months. In addition, there will be more arctic outbreaks this winter season, especially in January and February.
The beginning of October is when we start noticing signs of what kind of pattern we will experience for the next several months. This October was unusually wet with above-normal precipitation and warmer-than-normal temperatures. In November we went through another pattern shift. While there have been frequent systems and fronts that have passed through the area keeping us unseasonably cool, our precipitation is below average. In fact, we have yet to record any measurable snow this season, and that’s the way it is expected to remain through the end of the month.
The wild card in all of this is the La Niña. Sea surface temperatures over the past week or so have been dropping, and as the water in the Pacific Ocean begins cooling that will alter the overall pattern this winter, spring and summer.
In addition to temperature extremes, La Niña also has a big influence how much snowfall regions can expect during the winter. When you look at the records, a more moderate La Niña means above-average snowfall for those of us in Nebraska, while a weak La Niña brings lower snow totals. This La Niña event appears to be on the weaker side.
So exactly how does La Niña influence or impact our weather? Specifically, it alters the rain, snow, temperatures and atmospheric pressure, and it has a great impact on the northern jet steam allowing arctic outbreaks but not necessarily more snow. Our current thinking is that we will experience more frequent systems but they won’t necessary be major storms with significant snowfall.
Omaha’s average snowfall is almost 26 inches, but last year we only collected a little more than 11 inches. This year we are forecasting 17-21 inches, which is still below average, but almost double the amount we received last year.