05/20/2019 Forecast Update


Monday, May 20th, 2019 through Friday, May 24th, 2019

Ozone: 8-hour Ozone concentrations will be mostly Good with a few Moderates possible Thursday and/or Friday.

PM-2.5: 24-hour Fine Particulate concentrations are expected to range from middle Good to low Moderate through the week.


Cool, cloudy conditions on Monday turn warmer as the week progresses; however, a more active pattern will also develop. After a mostly dry Tuesday, precipitation comes in the forecast through Wednesday as a low-pressure area tracks north of the region. Past mid-week an upper level ridge builds across the southeast, but a surface boundary lingers further north across our region through the weekend. Disturbances moving across this boundary will keep scattered showers and storms in the forecast as temperatures and humidity levels increase.

Ozone is expected to remain Good through Wednesday, but readings could reach Moderate Thursday and/or Friday if precipitation remains at bay and afternoon sunshine breaks out for a few hours. Fine particulate may also increase into the Moderate range starting Wednesday, especially in the southeast.


Extended models show the boundary possibly lingering through the Memorial Day holiday. Since the placement of this boundary is important in determining air quality levels, we will be having another regional forecast call Friday to better evaluate expected conditions through the holiday weekend.

Next forecast update: Friday, May 24th, 2019
Update by: Stephanie M. Hengesbach