Did you notice the hazy sky on Monday?
The sky is usually clear and blue the day after a cool front passes, so why is it so hazy?
The upper-air wind pattern over the Continental US is blowing smoke: right out of the western US and southern Canada into North Alabama.
Tiny particles from that wildfire smoke gets lofted high up into the atmosphere (around 2 to 3 miles above the ground) and carried hundreds to thousands of miles.
That layer of smoky air gets between us and the sun altering how sunlight reaches us.
Instead of the normal blue caused by a ‘Rayleigh Scattering’ of light hitting molecules that naturally occur in the atmosphere, we get ‘Mie Scattering’ which tends to scatter more white light giving the sky a milky, white color mixed with the normal blue.
In the evening, it makes for an especially red sunset like this one from Ramona Edwards in Huntsville Sunday evening:
It's fairly easy to spot this happening on the new GOES-16 satellite imagery, and it's even more apparent in the NOAA smoke/air quality analysis for Monday:
Sometimes our haze is caused by other natural phenomena like dust storms...in the Sahara Desert. Over five thousand miles away. The hazy-looking sky actually does become more Saharan Dust than smoke later this week.