Forecast Discussion

Current daily average fine particulate concentrations are in the low-to-mid Code Orange range in the Piedmont and Sandhills, with upper Code Yellow conditions elsewhere. NOTE: The Code Red AQA today has been replaced with Code Orange statewide. Current ozone concentrations have risen into the Code Yellow range in the southern half of the state with localized Code Orange conditions southeast of Charlotte; Code Green ozone concentrations are being observed in the northern half of the state.

Smoky conditions will persist across North Carolina on Thursday, as the upper-level closed low continues to funnel Canadian wildfire smoke down across the eastern US. With continued light winds out of the NNW tomorrow and elevated fine particulate levels in our source airmass to the north, a widespread Code ORANGE Air Quality Action Day will be in effect statewide from midnight tonight (6/7/23) to midnight tomorrow (6/8/23). Air quality and smoke model guidance have been struggling with the complexity and behavior of this very challenging air quality episode. Observations and trends will be closely watched this evening and overnight, and any adjustments will be made in the morning forecast update. We expect ozone to temper some tomorrow based on upwind observations, with Code Yellow levels in the Piedmont and Sandhills and Code Green levels in the western and eastern portions of the state.

For Friday, Code Orange fine particulate conditions are expected to persist statewide as the large-scale synoptic setup remains in place. Sunny skies and ongoing smoke impacts will allow ozone concentrations to rise into the Code Yellow range statewide on Friday. On Saturday, the low pressure system that has been parked over the northeast US will finally begin to move eastward, allowing for some relief especially in the afternoon/evening. Both fine particulate and ozone concentrations should hold in the Code Yellow range on Saturday.