University of Georgia
Athens, Ga. -- Drought conditions are expected to continue across much of Georgia through spring 2008 and may expand into southeast Georgia by spring. A La Niña climate pattern has developed, which increases the probability of a dry, warm winter and spring across most of the state.
Current predictions from the National Oceanic and Atmospheric Administration Climate Prediction Center are for a weak to moderate La Niña to persist through early 2008. The climate pattern may intensify during the next three months, according to the CPC.
The effects of the La Niña pattern differ with its strength. These differences are critical across north and central Georgia, potentially having major impacts on the current drought and the region's ability to recover this winter and spring.
A weak La Niña climate pattern typically brings a warm, dry winter and spring to south Georgia. However, under weak conditions, there is a transition zone across the piedmont region, with a tendency toward wetter-than-normal conditions across extreme north Georgia.
With a moderate to strong La Niña, the transition zone from dry winters and springs to wetter-than-normal conditions moves to the extreme northwest corner of Georgia. These conditions would make the entire state much more likely to have a dry, warm winter and spring.
Compared to a weak La Niña pattern, the average total rainfall across north Georgia for November through February is drier with a moderate pattern by 4.97 inches in Athens, 5.47 in Atlanta, 5.59 in Cornelia, 7.75 in Gainesville and 7.23 in Rome. For spring (March through May), the moderate pattern is drier by 3.84 inches in Athens, 3.74 in Atlanta, 2.77 in Cornelia, 3.33 in Gainesville and 0.88 in Rome.
Regardless of the strength of the current La Niña, there is a significant probability that central and south Georgia will have a warm, dry winter and spring. If the pattern becomes moderate to strong, a warm, dry winter and spring will be even more probable.
Across north Georgia, the strength of the La Niña will be critical in determining where the transition zone between drier- and wetter-than-normal winter and spring occurs. If the pattern is weak, the transition region will normally occur south of the mountains across the piedmont. If it's moderate, there is a high probability that all except the extreme northwest corner will be warm and dry through spring.
The CPC winter outlook is for below-normal precipitation statewide, with the probability ranging from greater than 65 percent in extreme southeast Georgia to 50-to-55 percent across the foothills into the mountains. Across middle Georgia, the probability of a drier-than-normal winter is about 60 percent.
The probability of a warmer-than-normal winter is greater than 60 percent south of a line from near Columbus to near Lincolnton. North of this line, the probability of a warmer-than-normal winter ranges from 55 percent to 60 percent.
The CPC spring outlook is drier than normal, with the probability greater than 60 percent across the southern coastal plain, between 55 percent and 60 percent across the northern coastal plain into the piedmont and 50 percent to 55 percent across the foothills and mountains.
If a moderate La Niña pattern develops, there is a high likelihood that north and west Georgia won't be able to recover from the drought this winter.
The extreme- to exceptional-drought regions of the state may muddle through the winter and early spring. But without significant recharge of the soil moisture, groundwater, streams and reservoirs, conditions next summer could become catastrophic.
Regardless of the strength of the La Niña pattern, areas of southeast Georgia that aren't classified as being in drought could be experiencing drought conditions by spring.
Water-conservation and drought-management tips for home, garden, landscapes and pets can be found at www.caes.uga.edu/topics/disasters/drought/home/index.
Get updated drought information at www.georgiadrought.org. The Web site includes information on how to deal with the drought.
Updated weather information is at www.georgiaweather.net. This University of Georgia network has 71 automated weather stations statewide.
(David Emory Stooksbury is the state climatologist and a professor of engineering and atmospheric sciences in the University of Georgia College of Agricultural and Environmental Sciences.)