A relatively calm week weather-wise lies ahead of us, but that’s not to say there is nothing going on up in our atmosphere. Wednesday night into Thursday, a fast-moving, weak clipper system from Canada will race across the Northern Plains and Upper Great Lakes. A weak cold front following this system will spawn flurries along its passage, but several rounds of lake-effect snow this week will be the real cause of light accumulations.
Every winter, shots of cold, Canadian air allow snow showers, and sometimes storms, to form off the Great Lakes, burying the region in snow. This winter has been no exception so far, and this week temperatures are below average for the entire lower 48. Around late morning a few light snow showers are ending in Buffalo and the surrounding area in Upstate NY. More lake-effect snow showers are possible for MI and WI late tonight, but little to no accumulation is expected.
Similarly, Thursday’s system likely won’t bring much more than a few inches, and only about an inch of accumulation, by the end of the day. A weak cold front is expected to drape down from the low pressure center in Canada. Lift of air from this front will lead to snow showers along and behind it. A cold beginning of the week will have led to minimal available moisture, meaning that precipitation will be light. In addition to being light, a stronger high pressure will ensure the system’s speedy exit from the region by early Friday.
The main concern with this system, however, is not the cold frontal precipitation, but the lake effect snow to follow it. This cold front will do exactly what its name suggests, bringing a front of cold air into the region. This cold air will move over relatively warmer, moist lake water. Water vapor is picked up by the cold, dry air mass and, when it hits land, this air mass is lifted and the water vapor condenses or freezes. This frozen water falls out as snow, or other wintry precip, causing what we know as lake-effect snow.
Lake-effect snow will likely add a few inches on top of the cold front flurries Thursday into Friday. These bands of lake-effect snow may be heavy at times. In addition to blustery winds, this could cause quick and severe drops in visibility and road conditions. Thursday evening and Friday morning commutes will likely be messy, despite this not being a significant storm. It is advised to leave extra travel time to account for slower driving and delays.
Temperatures behind this system will be noticeably colder across the Northeast on Friday, with temperatures up to 10 degrees lower than the day before. With continuous shots of cold air, light lake effect snow could possibly continue to dust the Upper Great Lakes into this weekend, just before our next possible storm system arrives.