Forecast Discussion

Current hourly ozone readings are in Code Yellow range across the Ridge Tops and isolated portions across the southern tier of the state but are in Code Green range elsewhere. Daily averages of fine particulates are in Code Green range statewide.

An upper-level low will depart from the eastern US on Friday and we'll see rising heights as ridging begins to take shape. At the surface, high pressure will be over the state and will be centered offshore. Across the western half of the state, light and variable winds will are expected in the morning before a light southerly flow develops in the afternoon. Lights winds, coupled with abundant sunshine and a warm and dry airmass should be favorable for ozone production across the southern Piedmont where maximum 8-hour averages are likely to finish in Code Yellow range. Across the eastern half of the state, surface winds are likely to be a little stronger and out of the northwest to west which should keep ozone in Code Green range. As for fine particulates, the return of southerly flow should bring a slight uptick in daily averages compared to Thursday. However, with the airshed still fairly clean and mid-level back trajectories pointing towards clean air up towards the Great Lakes, averages should remain in Code Green range.

We'll continue to see a strengthening upper-level ridge over the state this weekend which will bring much warmer temperatures with many places reaching into the 80s on Saturday and upper 80s and low 90s on Sunday. High pressure will remain at the surface which will promote sinking air and some stagnation. With warm temperatures, abundant sunshine, and only modest dew point increases, conditions should be quite favorable for ozone production with much of the state in Code Yellow range and the Charlotte region in mid to upper Code Yellow range. Fine particulates will also continue to increase through the weekend with Code Yellow daily averages expected across the Piedmont by Sunday.