Elevated Forest Fire Danger

The persistent drought that we have been experiencing is causing some trees to begin the process of leaf fall, especially the tulip poplar and black birch trees. Both of these trees display yellow coloration. Also, the black gum trees, one of the first trees to display fall colors, are beginning to show their fall red colors. Look for this leaf change in the higher elevations.

The lack of rain we have been experiencing is resulting in increased forest fire danger throughout our region. A measure of the “drought index” as it relates to forest fire potential was developed by researchers with the US Forest Service in 1968 and is known as the Keetch-Bryam drought index or KBDI. KBDI readings range from 0 to 800: the higher the reading, the more severe the drought potential. The KBDI for Frederick County on September 15, 2010 is 655. This reading indicates that we are now in a more severe drought, there is increased chance of forest fires starting, the fires will burn with more intensity, and fires can burn deep into the ground. At these levels living “green” fuels can also burn. As a rule of thumb, it would take about one inch of rain to decrease the KBDI index 100 points so we need 6.55 inches of precipitation to reduce this number to 0. In an average year our KBDI readings are in the range of 200 – 400 during mid-September.

The prognosis: our forest fire potential will be at the Moderate to High range until we receive more rain. We recommend that you refrain from burning brush until we receive more rain. If you must burn, please remember to obey the burning regulations (if you are within 200 feet of any woodland) meaning that you a. burn between 4:00 pm and 12:00 am, b. a responsible person is on site during the burning, and c. You create a 10’ safety strip around the fire so it does not escape. It is also wise to assess the current weather conditions before you burn; if it is sunny, windy, and warm you should not be burning.

Nature Notes for 9/19/2010