It’s still shaping up to be a soggy weekend, with a pretty good chance of at least occasional showers Saturday and Sunday. The merging of a weak low from the south with a stronger trough of low pressure coming in off the ocean will drive a front across the region, giving us nearly an even chance of measureable precipitation Saturday and occasional rain showers Sunday and Monday in its wake. Temperatures will fall to the mid-70s Saturday and continue to drop into the upper-60s by Monday before climbing back into the 70s with clearing conditions by Tuesday.
So why do leaves turn colors in the fall, anyway? You can actually look at it this way: leaves don’t change color in the fall… they just become their true color in the fall. There are three pigments in leaves: Chlorophylls, Carotenoids, and Anthocyanins. Chlorophyll is necessary for photosynthesis, which produces sugars the tree needs for food. During the spring and summer growing seasons, the bright green of the chlorophyll tends to wipe out the browns, reds and yellows that are produced by the other pigments. But as the tree begins to go dormant in the fall, the production of chlorophyll slows and stops and any left in the leaves breaks down and disappears. At that point, the Carotenoids and Anthocyanins remain giving the leaves their bright fall colors.