PORTLAND, Ore. (KOIN) — Are you prepared for a La Niña winter?
“Sure! But what does that even mean?” you may ask.
Well before we talk about it, let me start by saying that this weather blog is not a snow forecast. Forecasting exact snow totals at this point is about as useful as throwing darts away from the bull’s eye, but we can examine past snow totals during La Niña phases.
If you aren’t familiar with the terms La Niña or El Niño, you should check out this KOIN 6 Weather explainer here. Now, keep your eyes peeled for our KOIN 6 Winter Outlook. Our morning meteorologist, Kelley Bayern, is diving deeper into the snow….so to speak…examining La Niña winters of the past and offering snowfall probabilities.
So, we’re on track for a La Niña winter. Now what?
La Niña represents cooler than normal ocean water in the Equatorial Pacific. This has a global impact on weather patterns.
CHECK OUT THE GRAPHIC BELOW
Last winter we were in a weak El Niño phase (warmer than normal water in the Equatorial Pacific). It just so happens this year we are transitioning to the cooler than normal ocean water. For the 2020-21 winter months, according to the climate division of the National Oceanic and Atmospheric Administration, we are at an 85% chance for La Niña conditions to continue through the winter in the Northern Hemisphere. They also believe that we are going to possibly see a stronger La Niña. With that, they have issued a La Niña advisory, meaning conditions are observed and expected to continue.
WHAT COULD THIS MEAN FOR US?
La Niña winters tend to bring in wetter and colder conditions for our region. It is important to note that this doesn’t occur every time. We’ve had La Niña winters that have been docile and mild. We have also had some very snowy winters come from a La Niña winter (think 2008-2009 24+ inches of snow). The last La Niña winter greeted us in 2017-2018, when Portland collected 7.6 inches of snow. That sure beats out our weak 0.5 inch from our 2019-2020 winter.
Check out the graphic below! It gives a visual for the weather pattern that may play out during the wintertime. High pressure tends to develop over the Pacific, which may lead to that jet cutting from the north down to the south through the Pacific Northwest and into the Midwest. This may usher in multiple waves from the northwest, bringing in colder air and the potential for mountain snow.
With that information, you can start thinking about what you may want to do this winter. Were you hoping to get out for some skiing or snowboarding? Traveling for the winter and want to go somewhere warm and dry? Just hoping for a little snow around the metro area? A La Niña winter pattern has the capability of delivering just about everything for everyone.
Before we close this out, the Climate Prediction Center (CPC) has a winter outlook for the months of December, January, and February. Below are two maps that represent the temperature and precipitation outlook for those three months. You may notice a trend from the map above. Cooler and wetter around our neck of the woods.