We’ve had a mix of varying weather conditions this autumn. October started off warm and dry with a minimal drought ending abruptly after all the rain around the middle of the month. Colder air has now worked its way into the D.C. area this week, with many of you having already seen your first frost and some high elevations their first snowflakes. Although meteorological conditions this year may not be the most optimal for viewing fall foliage, there are still places with some bright colors.
Depending on where you are, fall foliage viewing ranges anywhere from past peak within the western mountains, to moderate color around the District and on the Eastern Shore.
The foliage Network writes, “Color change continues to progress along the Appalachian Mountains. In western Maryland and eastern West Virginia, color change is peak to past peak. In western Virginia, western North Carolina and extreme eastern Tennessee, color change is mostly high (61% – 80% change). In the lower elevations and coastal locations, color change is moderate (31% – 60% change).”
Western suburbs should be nearing or are already past their peak colors, and downtown D.C. will have its peak within the next couple weeks as October transitions to November.
Many trees, many colors
Temperature and precipitation patterns have major effects on vegetation growth and coverage in a given area. The mid-Atlantic temperate forest biome has a variety of tree types. The Virginia Department of Forestry gives a list of trees that grow in this area. A few of the local deciduous trees that lose their leaves during the autumn season include the following…
The science behind fall foliage has a long way to go, but researchers now understand the basics. Local weather events do affect the timing of the foliage season, but the most important factor for fall foliage may not be weather dependent, according to the United States Department of Agriculture Forest Service:
“The timing of color change and leaf fall are primarily regulated by the calendar, that is, the increasing length of night. None of the other environmental influences – temperature, rainfall, food supply, and so on – are as unvarying as the steadily increasing length of night during autumn.”
As the autumn season progresses, leaves gradually transition from their healthy chlorophyll-filled greenery to vibrant red blends. The website, exploreasheville.com, gives an explanation on how this happens:
“Researchers figured out that as the chlorophyll vanished, the energy from the sun could damage the mechanism by which the trees reabsorbed nutrients. Research proved it out: mutant trees that produced no anthocyanin turned out to absorb much less nutrients from leaves than those that turned red.”
Over the next several weeks the foliage will gradually come and go from west to east. Wintry weather has already shown its face for some and regional overnight frosts are becoming more widespread. There’s still some time to make the most of the fall foliage, but that might not last much longer.
The author, Brendan Richardson, is a Capital Weather Gang fall intern. Brendan recently earned his Bachelor of Science double major degree in Earth Science with a Concentration in Atmospheric Science; and Global and Environmental Change from George Mason University.