NORTH DAKOTA (KXNET) — North Dakota can look vastly different each fall season. This year, it’s been very cold and it all stems from our upper atmospheric patterns.
There are several circulations we look at around the globe that can impact us here in North Dakota.
The one we’re impacted by the easiest is the Arctic oscillation. When it’s in the negative phase, the jet stream buckles more and allows for Arctic air to spill into the United States. A positive phase would be if the jet stream were higher and tighter, not allowing for cold air to spill down.
Another oscillation we look at is what’s called the North Atlantic Oscillation. It’s measured in – you guessed it – the northern Atlantic. A strong high-pressure system measured here makes the jet stream buckle which also allows cold air to freely flow into the U.S.
But that isn’t the only body of water we watch. We also watch the Pacific for what’s known as the Pacific North American Pattern. When it’s in its negative phase, certain pressure systems also make the jet stream buckle. Typically this pattern is what can give us not only colder air but snowstorms.
So when we have all three of these patterns happening at once, they help each other stall out. Which continues to funnel in cold air into the Upper Plains. This is why we’ve been so cold lately. These oscillations have allowed cold air to take over.
To add to the cold pattern list, the long-range forecaster at the National Weather Service, Megan Jones, says we’ve probably now settled into our La Nina pattern for the winter. This means we have a good chance of continuing the cold air outbreaks.