Forecast Discussion

Current daily average particle pollution levels are rising into the upper Code Yellow range from Charlotte to the Triad and points westward, while gradually rising into the mid Code Yellow range along and west of I-95. Hourly ozone levels are rising into the Code Yellow range in the Charlotte region, and continue to remain in the Code Yellow range at high elevation sites.

Tomorrow, surface-level Canadian wildfire smoke will remain entrenched as the region is sandwiched between strong upper-level ridging over Texas and an upper-level trough swinging eastward across southern Canada and the northern Great Lakes. The results of this atmospheric flow pattern will be continued northwesterly flow aloft, which has been responsible for the transport of the Canadian smoke into the region.

At the surface, weak high pressure overhead will result in a strong overnight temperature inversion, which will act as a lid to trap smoke and elevated particle pollution near the ground overnight into tomorrow morning. Hourly concentrations overnight may rise into the 50 to 60 microgram per cubic meter (Code Red) range, but are expected to gradually reduce tomorrow as atmospheric mixing increases. Additionally, although slow, it is anticipated that a slightly less-polluted air mass will gradually work in from west to east tomorrow afternoon and evening.

All things considered, we expect air quality impacts from smoke to be greatest tomorrow morning, with gradually improving conditions as the day progresses.

Thursday into Friday, expect slowly improving conditions during this period. Currently, we expect particle pollution concentrations to remain below the Code Orange threshold with the continued pattern of overnight elevated hourly values slowly decreasing during the day. Several upper level disturbances approaching from the west should produce scattered to mostly cloudy skies, which should temper ozone production.