Right combination of weather and terrain makes Missouri a popular destination for leaf peepers
Story written by Jeff Huffman
Story posted on September 30, 2008
The heavy morning dew and crisp chill in the air this morning was a sure sign that autumn is here. Many of you probably consider it your favorite time of year. And along with football, playoff baseball, and those bright yellow mums comes another spectacular sight - the changing colors of our foliage.
MISSOURI'S COLOR IS SOME OF THE BEST!
Missouri is one of the better states in the country to experience nature's kaleidoscope in the fall. We seem to have the right mix of hilly terrain and deep vegetation, along with just enough highway infrastructure to make it very convenient for leaf peeping. On average, our leaves in Mid-Missouri are the brightest in mid to late October; more specifically, October 20th. The peak usually occurs a bit sooner in the mountaneous terrain of the Ozarks (see map below), where the hilltops provide more shade and cooler nighttime temperatures. The right combination of warm, sunny days and cool, crisp nights we often have in the month of September really increases the chances for some post-summer splendor.
Map showing when the leaves are usually at their peak in color around the U.S.
2008 FALL FOLIAGE FORECAST
The color in Mid-Missouri over the past two years has been rather disappointing, to say the least. In both years, drought conditions and extreme late-summer heat resulted in very dull color. However, this year, conditions seem to be favorable for a very vibrant display! The abundant rainfall during the latter half of our summer, combined with the cooler than normal temperatures we had in August, have resulted in very healthy vegetation this fall. The recent trend of mild, dry weather has allowed the process of change to take full effect. If we continue to see normal rainfall and relatively mild temperatures through mid-October, we should have one of the best shows from mother nature that we have seen in quite some time. There are only two obstacles I see that might get in our way of seeing this year's masterpiece: high winds and/or an early season frost. There are signs that the weather pattern may be quite active around the middle of October, possibly sending some high winds our way that would cause leaves to fall before they change entirely. They just aren't as fun to look at in a pile waiting to be bagged, are they? Another negative is that, along with the active weather pattern, may come an early season blast of cold enough air to produce frost. The weight of a frost or freeze on the leaves before they change color would also almost certainly lead to premature leaf drop.
As of today, we expect this year's peak to occur a bit earlier than normal due to the unseasonably cool weather developing over the next week or so. It is also possible that the color change will occur more rapidly than normal due to the anticipated cloudier days forecasted for the second week of the month (the more active period described above). Therefore, leaf peepers are encouraged to be on stand by during the week of October 12th for their annual trips, with the possibility of our peak occuring by the following weekend (18-19). However, different trees do change color at different times during the season making it possible to see good color spread over multiple weeks.
We will keep you updated on the fall foliage as it develops, along with the forecast, on our Stormtrack Blog. For more information on this year's statewide forecast, please visit the Missouri Department of Conservation's website.
HOW DO THEY DO IT?
Healthy leaves need plenty of moisture and sunlight - but not too much - for photosynthesis and chlorophyl production (which gives the leaves their dominant green color). As the days get shorter, there is not enough light or water for photosynthesis. The trees will rest, and live off the food they stored during the summer. They begin to shut down their food-making factories. The green chlorophyll disappears from the leaves. As the bright green fades away, we begin to see yellow and orange colors. Small amounts of these colors have been in the leaves all along. We just can't see them in the summer, because they are covered up by the green chlorophyll. The bright reds and purples we see in leaves are made mostly in the fall. In some trees, like maples, glucose is trapped in the leaves after photosynthesis stops. Sunlight and the cool nights of autumn cause the leaves turn this glucose into a red color. The brown color of trees like oaks is made from wastes left in the leaves. It is the combination of all these things that make the beautiful colors we enjoy in the fall.