For the second day in a row, the National Weather Service issued a high fire danger alert for Cobb County and other counties in the region. Low relative humidity, dry conditions, and possible wind gusts create conditions for the rapid spread of fire.
What is in the statement?
The statement gives the following details:
…HIGH FIRE DANGER CONDITIONS THIS AFTERNOON INTO THE EVENING
FOR PARTS OF NORTH AND CENTRAL GEORGIA DUE TO LOW RELATIVE
HUMIDITIES…
Relative Humidities of 25 percent or less can be expected for 4
or more hours this afternoon into the evening. Winds will be west
or southwest at 5 to 10 mph. Gusts to around 20 mph will be
possible during the afternoon.
With dry fuels, high fire danger conditions can be expected.
Please refer to your local burn permitting authorities
whether you may burn outdoors. If you do burn outside,
use extreme caution.
Why does low relative humidity increase the danger of fire?
The National Park Service published the following explanation of why low relative humidity increases the danger of fires:
“Relative humidity is important because dead forest fuels and the air are always exchanging moisture. Low humidity takes moisture from the fuels, and fuels in turn, take moisture from the air when the humidity is high.
“Light fuels, such as grass and pine needles, gain and lose moisture quickly with changes in relative humidity. When the RH drops, fire behavior increases because these fine fuels become drier.
“Heavy fuels, on the other hand, respond to humidity changes more slowly. To see significant changes in heavy fuel moisture, there must be significant moisture, usually from more than a single storm.”
What counties are affected?
The following counties are included in the hazardous weather outlook:
Baldwin, Banks, Barrow, Bartow, Bibb, Bleckley, Butts, Carroll, Catoosa, Chattahoochee, Cherokee, Clarke, Clayton, Cobb, Coweta, Crawford, Crisp,…
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