WEATHER-TRAFFIC UPDATE: MARTA’s mechanical issues causing delays

ATLANTA FORECAST

Wednesday: High: 89

Wednesday night: Low: 64

Thursday: High: 90

» For a detailed forecast, visit The Atlanta Journal-Constitution weather page.

Lingering traffic delays are being compounded by new wrecks along the Downtown Connector and many sections of the northern Perimeter during the evening commute.

All I-75 South lanes have now reopened after an earlier major injury crash involving a tractor-trailer, according to the WSB 24-hour Traffic Center.

A truck ran into the woods on Ga. 20 near Ga. 108 in Cherokee County, the Traffic Center reported. A few miles of Ga. 20 has been shut down as a result, and Stamp Creek and White Road are recommended detours.

A wreck on I-85 North at Ga. 400 has been cleared, but delays remain nearby, the Traffic Center reported.

Multiple lanes on I-285 near Chamblee Tucker Road have been reopened following pothole repairs, but delays remain, according to the Traffic Center.

MARTA isn’t safe from delays, either. Mechanical issues on the Red and Gold lines have delayed both routes by about 15 minutes, according to a tweet.

The Georgia Department of Natural Resources issued a Code Orange air quality alert, which means sensitive groups, such as children and those with respiratory issues, should avoid prolonged time outdoors Wednesday.

RELATED: Air quality forecast for Atlanta

MORE: What does a Code Orange air quality alert mean?

ALSO: Track air quality levels in your neighborhood

Channel 2 Action News meteorologist Brad Nitz said it reached 91 degrees today, which is 2 degrees warmer than the predicted high.

The decrease in air quality is due to the area of high pressure hovering over Tennessee.

"It will trap the air (Wednesday), making it stagnant and not allowing it to breathe or move, and that's going to present an issue regarding air stagnation and air quality," Channel 2 Chief meteorologist Glenn Burns said.

Hot temperatures are expected continue the rest of this week, and humidity is forecast to stay in the 50 to 60 percent range. More tropical moisture is on tap for Friday through the weekend, however.

There is now a 20 percent chance of rain Friday, which increases to 30 percent Saturday and 40 percent Sunday. Saturday’s storms are expected to be isolated, while Sunday’s will be more widespread, according to Channel 2.