Cool fall air is sweeping across Middle Tennessee as a front moves across the state. The temperature in Nashville dropped almost 10 degrees from 2:30 to 5:30 this afternoon. By morning the low will be near 50 again.
Unlike today, temperatures will not rebound tomorrow. A big area of low pressure now over the Great Lakes will slowly drop southward keeping clouds and some showers in the mid-state through Friday. As a result temperatures will be held down to the upper 60s tomorrow and near 70 Friday.
The low pulls away Saturday leaving behind great weekend weather. The highs will rebound to the mid to upper 70s over the weekend.
Fall is in full swing the temperatures are cool, almost chilly, so many folks are getting ready for checking out the annual explosion of fall foliage. Weather does have an effect on the color…usually a drop in the temperatures and a change in the amount of daily sunlight are the usual triggers for trees to start shutting down for the winter and as a result changing the color of their leaves. The intensity and timing of that change is tied in part to summer and fall temperatures and rainfall.
Generally speaking, temperatures and precipitation each year are helpful predictors for when that blast of color will occur at a certain latitude. High heat stress or drought can cause colors to appear earlier and disappear faster. Even moderate heat stress can delay the color transition.
An increase in rainfall usually delays the appearance of color, but too much rain can be stressful for the trees and also cause leaves to change color early.
My colleagues at Climate Central point out that with climate change expected to alter both temperatures and precipitation, fall foliage will also be affected. My colleagues at Climate Central point out , “Projections for the end of the century suggest the warmer temperatures would delay the onset of peak colors, but also make them disappear sooner, leading to a shorter season. Nationwide precipitation projections are a bit less certain, but signs point to an increase in the Northeast, further delaying fall colors there. The effects of this are both ecologically and economically important. Leaf-peeping is a multi-billion dollar a year ecotourism industry for many states.” Tennessee is one of those states. The Great Smokey Mountains is the most visited National Park in the country and fall is a popular time.
I’ll have an update on the weather for the rest of the week on Channel 4 News at 10pm.
posted 8:55 PM