HOUSTON - There is an air quality alert for ozone in Harris, Galveston and Brazoria counties through 7 p.m. today.
We tend to see these a lot in the summertime because ozone forms through a chemical reaction with sunlight. While its presence in the stratosphere blocks harmful incoming UV radiation, at ground levels it can be problematic.
What it means for our area
As high pressure continues to build directly overhead, winds will get lighter on Thursday and Friday. High pressure is not only associated with sunny (meaning more ozone) and dry weather, but also a stable/stagnant air mass. That means there will not be a lot of wind to mix things out, or much rain if any in sight to wash things away.
High pressure also means that air is sinking, and it traps these air pollutants near the ground where they can be bothersome if you have asthma or other respiratory issues.
If you notice a bit of haze to the sky the next few days, or are having difficulty breathing after spending extended periods of time outside, this could be why.