Cold July Tuesday… but no polar vortex

After all of the rain yesterday, unseasonably cold air has moved into the Finger Lakes, and really the entire eastern half of the nation. Must be the dreaded polar vortex, right?Wrong.The polar vortex has become a misused buzz word to describe any cold air mass. In reality though, the polar vortex is an area of low pressure near the north (and south) pole that is formed by the global wind patterns. It is a semi-permanent feature, only disappearing sometimes in the summer when it weakens. It is much stronger in the winter months.A strong ridge of high pressure over northern Canada, shown in the orange and red colors, currently exists between the polar vortex and the culprit of our cool weather: a large upper level low situated on the southeast shore of the Hudson Bay. This storm system, not the polar vortex, is keeping our temperatures low.This low pressure system is stalled out due to high pressure of the Atlantic Ocean and Greenland. It’s movement is completely blocked, so it will remain about where it is now for a while- maybe a week or more. It will eventually dissipate or move away, but for now, we will be influenced by its ebbs and flows in strength and position.In addition to supplying the region with a fresh dose of cool air, there are numerous disturbances rotating around the low. While we should be between disturbances today, and thus mostly dry, showers and thunderstorms are possible Wednesday and Thursday, and possibly even into the weekend.

Also on FingerLakes1.com