New York City and Washington had their worst particle pollution on record Wednesday and Thursday as wildfire smoke poured south from Canada. A few parts of the Mid-Atlantic were still dealing with smoke-filled skies at the start of the day Friday, but conditions were rapidly improving west to east.
Air quality alerts are in effect into Friday from Washington to Connecticut and points east, as well as in Pennsylvania, Upstate New York and parts of the Ohio Valley and Great Lakes. Most of the alerts correspond to air qualities in the code orange range — not as bad as the code red or code purple alerts hoisted earlier in the week. The smoke should begin to subside during the evening hours Friday.
A high-resolution weather forecast model known as the HRRR, which simulates atmospheric features, suggests that one last thinning plume of smoke — moderate in some places — will gradually head offshore and dissipate while continuing to affect parts of the Northeast through evening.
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End of carouselBelow is a forecast based on that model; note that it is not perfect and that actual conditions may vary from its projections.
Friday
While patches of poor air quality hung across Michigan, Ohio, Pennsylvania, eastern Virginia and the Delmarva Peninsula, the overall trend was improvement. Computer modeling indicates the smoke is largely dispersing. Washington, which awoke to visibility around 1.25 miles Thursday morning, had 10-mile visibility to start the day Friday.
There could still be some smoke, perhaps thick at times, in central and southern Pennsylvania and Maryland and around Washington in the afternoon, although it is likely that weather models are being overly bullish in their simulations. Otherwise, it should all head offshore Friday night.
Friday night and beyond
The smoke is being cycled through the Northeast and the Mid-Atlantic by a low-pressure system spinning counterclockwise over northern New England and Nova Scotia.
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Beyond Friday afternoon, the low-pressure zone will be drifting to the north and weakening. This should allow smoke plumes to disperse somewhat as the steering flow from the north subsides. By Saturday, a greater westerly component to the wind should reduce the smoke in most areas. However, parts of western New York state may see a renewed filament of smoke drop out of Canada, although confidence is low.
On Sunday, some smoke may drift into Maine, which has largely escaped it so far.
As long as the fires burn in Canada, steering currents in the atmosphere may direct smoke into different parts of the Lower 48 states in the coming weeks. The fire season in Canada is only beginning, so we are likely to see more bouts of smoke through summer.
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