There is a Code Orange in place for a portion of the area on Friday, May 20th.
Why the poor air quality?
Typically we have the warmest air at the surface with cooler air higher up in the atmosphere. On these “normal” condition days, any pollutants at the surface will rise. Due to what is called a ‘cap’ or a layer of relatively warm air aloft, the rising air cannot escape, therefore the haze/pollution is trapped at the surface. Think of a cap as a lid.
The reason for the poor air quality on Friday is due to high levels of ground-level Ozone. Ozone up high in the atmosphere is a good thing as it blocks UV light. Ozone at the surface is not good. Emissions at the ground level interact with sunlight and heat which causes a chemical reaction.
The Code Orange in place Friday is for sensitive groups. Sensitive groups include people with heart and lung disease, children and older adults or people that are active for a prolonged time outdoors.
If you are any of those listed above, it is best to reduce your exposure outdoors. If you must be out, earlier or later in the day is best as ozone levels are not as high.
