Fallen maple leaves carpet a lawn across the street from the First Baptist Church of Kingfield, Maine, Sept. 30. (AP Photo/Robert F. Bukaty)
The leaves on the trees have taken on their fall colors as seen over a stream Friday, Oct. 14, 2011 near Kingston, Pa. (AP Photo/Alex Brandon)
You may not have guessed it Sunday, when the high temperature reached 91 degrees in Tulsa, but it is indeed fall.
Well, hold on, because we’re about to get a stark reminder this week.
A big
cold front is set to blow through tonight, dropping forecast highs by 20 degrees, and bringing the first chance of a frost or even a freeze in some areas.
It will bring some rain, most likely after midnight tonight. Not a lot, but some. And it could be significant rains in storms.
But, it still remains dry, which is not good for fall foliage.
I
wrote Sunday about foliage road trips in eastern Oklahoma and western Arkansas. The vibrancy of the changing leaves may be
somewhat limited this year because of the drought conditions we’re experiencing.
As nights lengthen, a layer of cells begins to develop in the leaves, cutting off the transfer of materials between the leaf and the branch, including chlorophyll, which gives the leaf that green color during the growing season.
Chlorophyll production in the leaf slows and eventually stops and the green color fades, highlighting the other pigments in the leaf that provide the yellows, reds, purples and browns of fall.
In a drought during the growing season, that layer of cells can form early, causing the leaves to fall before they reach their full color potential. That makes for a sad fall.
However, so far this autumn has been dry, cool and sunny, which all are conducive to producing bright fall colors. So if the leaves can hang on for a few more weeks, eastern Oklahoma and western Arkansas could be in for a more colorful than expected fall.
--Jerry Wofford
