Forecast Discussion

New wildfires in Graham and McDowell County have prompted upgrades to a Code Orange Air Quality Action Day for PM2.5. Areas to the southeast of these fires could experience intermittent smoke this afternoon and evening. Elsewhere across the state, air quality remains in the Code Green range.

Tomorrow, weakening surface high pressure will build into the region from the west, continuing to deliver a cooler and drier than normal air mass through midweek, with air quality levels holding mostly in the Code Green range. Fire activity is likely to be ongoing and winds are expected to remain light but slowly veer to southeasterly, which would steer any smoke plumes to the north and west. This would put Yancey and Mitchell County in line to receive some smoke impacts tomorrow afternoon and as such, have issued a Code Orange for those locations for PM2.5.

Ozone levels may begin to rise tomorrow into the upper Code Green / low Code Yellow threshold in Charlotte due to a stagnating air mass, but cool temperatures should offset this some.

Friday into Saturday, an H5 ridge building overhead will occur concurrently with the surface high pressure sliding offshore. This will result in continued mostly sunny skies and an increasingly stagnant air mass that will likely result in both ozone and fine particulate levels gradually rising into the Code Yellow range. Additionally, increasing prescribed burn activity currently (if it persists, which we unfortunately have no way of knowing) would likely result in an increasingly smoke laden air mass that will exacerbate conditions. Ozone levels by Friday could elevate significantly depending on the amount of smoke in the air shed and we will continue to monitor for this potential.