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A perfect recipe for fall colors?

This may be the perfect year for vibrant fall colors around the Twin Cities metro.

This week the fall color "ring of fire" is closing in on the Twin Cities. Much of northern Minnesota is past peak, according to the latest fall color update from the Minnesota Department of Natural Resources.

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Minnesota DNR

Recipe for fall color

Like wine, every year is slightly different for leaf peepers in Minnesota.

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NOAA via Duluth NWS

I'm in the camp that says it's almost always a good fall color show in Minnesota. But there are differences each year in the trees physiology based on the weather that year.

What makes for a great fall color season?

It turns out Minnesota's 2014 weather may be producing a good show. Start out with a wet growing season, then turn of the faucet and dry things out in late summer and you may have a burst of October color. Throw in some sunny days and crisp nights and you're in business.

Here's more from the National Oceanic and Atmospheric Administration on exactly what ingredients go into a great fall color recipe:

Recipe for fabulous foliage? Cool nights and sunny days

Weather factors such as temperature, sunlight, precipitation and soil moisture influence fall color arrival, duration and vibrancy. According to United States National Arboretum, a wet growing season followed by a dry autumn filled with sunny days and cool, frostless nights results in the brightest palette of fall colors. Changes in weather can speed up, slow down or change the arrival time of fall’s colorful foliage. For example:

  • Drought conditions during late summer and early fall can trigger an early “shutdown” of trees as they prepare for winter. This causes leaves to fall early from trees without reaching their full color potential.

  • Freezing temperatures and hard frosts can kill the processes within a leaf and lead to poor fall color and an early separation from a tree.

True colors come from inside

Trees actually begin to show their true colors in autumn, and here’s why.

The four primary pigments that produce color within a leaf are: chlorophyll (green); xanthophylls (yellow); carotenoids (orange); and anthocyanins (reds and purples). During the warmer growing seasons, leaves produce chlorophyll to help plants create energy from light. The green pigment becomes dominant and masks the other pigments.

Trees must replenish the chlorophyll because sunlight causes it to fade over time. As days get shorter and nights become longer, trees prepare for winter and the next growing season by blocking off flow to and from a leaf’s stem. This process stops green chlorophyll from being replenished and causes the leaf’s green color to fade.

The fading green allows a leaf’s true colors to emerge, producing the dazzling array of orange, yellow, red and purple pigments we refer to as fall foliage.

Fall color is like a sweet reward for the inevitable changes this time of year. We say goodbye to summer, and savor every last sunny crisp morning and mild afternoon.

Enjoy the show while it lasts.

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Fall road in Deephaven. No turn around beyond? Paul Huttner/MPR News.