Wildfire smoke has been the headline over the last 24 hours and continues to be the biggest weather story Wednesday, as air quality has dipped to unhealthy levels for sensitive groups, owing to the smoke from wildfires that have been burning in Quebec. This wildfire smoke actually has encompassed much of the Eastern United States, driving air quality levels to unhealthy in places like Washington, DC, and parts of North Carolina. Here at home, a fresher breeze should disperse the smoke to lighter content by later Wednesday, resulting in a gradual improvement of air quality for the Boston Metro and northeast New England, though smoke will remain dense in Western New England. Both the surface wind and the steering wind aloft driving the plumes of smoke are directly linked to a large, very slow storm that continues to be stalled over Nova Scotia. As bundles of energy wrap around the storm’s counter-clockwise flow of air, dropping south over New England, rounds of clouds and showers blossom in that atmospheric energy, which is why our First Alert Team expects morning sprinkles and afternoon scattered showers to continue as the theme Wednesday through Friday. When enough difference between relatively warm surface air and cold sky air exists, as was the case Tuesday afternoon, thunder can develop within the showers, and we believe that possibility rises again Friday afternoon. Most New England communities will see daytime high temperatures in the 60s the rest of this week, though there will be exceptions: cooler exceptions in the cloudiest spots of Northern New England, and milder exceptions where the most sun is present in far Southern New England. The weekend brings improvement as the slow-moving storm over Atlantic Canada drifts east, so while a pop-up shower can’t be ruled out Saturday, most of the day should be enjoyable for New England with highs rebounding to either side of 70° and a blend of sun and clouds, then fantastic weather is expected Sunday as highs reach the 70s! Although not expected to be over Nova Scotia, a similarly slow-moving storm at the surface and aloft is expected to near the Northeastern U.S. early next week, raising the chance of showers in our exclusive First Alert 10-day forecast for Monday through Wednesday – we’ll continue to fine tune details as we get closer.

An Air Quality Alert continues from the Environmental Protection Agency for the southwestern half of New England and much of the Northeast United States as a result of wildfire smoke lingering in the air at low altitudes, casting haze across the sky and loading particulate matter into the air that poses a challenge for those with respiratory ailments and makes a noticeable difference for those who exercise strenuously. The smoke is the product of wildfires burning in the Canadian Province of Quebec – now our third source of Canadian wildfire smoke in the last several weeks. Several weeks ago, high-altitude smoke from Western Canada wildfires filled our sky, 2-3 weeks ago it was Nova Scotia’s wildfires and this week the source is Quebec, where dry conditions continue. Interestingly, the smoke it being blown southward into the United States by a stalled weather system that delivered much-needed rain to Nova Scotia, but the large, counter-clockwise wind flow around it has resulted in a prolonged northerly wind flow to the Northeast U.S. Of course, our sensible weather is very much impacted by that slow, large storm, as well, with repeated days of building clouds and showers punctuated mostly by slugs of dry air that bring increased periods of sun. One such sunny period Tuesday morning to midday helps to boost temperatures over 70 degrees for many before new afternoon showers and thunderstorms develop. Although it’s unlikely any storms will turn severe Tuesday late day and evening, it’s not entirely possible to get an isolated burst of locally strong wind in one or two communities, given the abundance of dry air aloft that can produce gusty wind at the center of well-developed downpours. Showers fade Tuesday night and no frost is expected in the coming nights under variable clouds, but do expect showers to start sooner Wednesday – as soon as predawn for some, with scattered showers coming and going over the course of the day, more clouds than Tuesday and somewhat cooler temperatures hovering in the 60s. Thursday and Friday both return New England to a pattern of sun, building clouds and scattered afternoon showers with a possible rumble of thunder as the large storm over Atlantic Canada only slowly nudges east, but should exit far enough east for improving weekend weather, when an afternoon pop-up shower isn’t impossible but does appear far less likely. That said, right now it looks like we may simply reload the showery pattern next week, starting as soon as Monday with another slow-moving, large storm at the surface and aloft at the jet stream level, this time perhaps closer to the Northeast U.S., with finer details TBD.