One hell of a cold snap is about to slide down this side of the globe – and it appears that this Arctic outbreak will have some staying power.
This image is 500mb mean heights from the GFS ensembles. What you need to notice here is the gigantic area over above normal heights from the Pacific Northwest right up through the North Pole and into eastern Scandanavia and northwestern Russia. This will effectively dislodge the cold over the North Pole and bring it south.
This “ridge bridge” across the Pole is how we get true Arctic Air south. Indeed, the Polar Vortex will “split” with one piece winding up over Hudson Bay and another over Siberia. What makes this quite unusual is how long the cold may stick around. Some signs keep the cold in place through the beginning of February!
The big question for me is will we see a snowstorm during this cold pattern? The answer is probably. This pattern will likely deliver some snow though the lack of blocking over the North Atlantic may preclude a major (Kocin-Uccelini) storm. The first window for a snowstorm I see is Thursday through Sunday of next week as the cold briefly lets up before quickly reloading.
Stay warm 🙂