Published on 10/22/09

Wetter, cooler winter headed to Georgia

By David Stooksbury
University of Georgia

Athens, Ga. – There is a high likelihood that Georgia’s winter will be wetter and cooler than normal.

The exception will be Georgia’s mountain region, which is near the transition from wetter-than-normal conditions to the south and drier-than-normal conditions to the north. Temperatures in the mountains will likely be below normal.

Due to heavy September and October rains, soils are already near saturation. Streams that are usually at their lowest flows during October are at levels normally seen in March, which is the month that generally has the highest flows. Because of this, the potential for winter flooding is higher than normal.

The ocean-atmosphere system is currently in the El Niño pattern. This pattern is expected to persist through the winter. Following an El Niño winter, it is not unusual for a drier-than-normal trend in spring.

El Niño’s influence is especially strong in the southern two-thirds of the state. The mountainous region of north Georgia and middle and east Tennessee is a transition zone. Depending on where the transition zone occurs this winter, the mountains will experience drier-than-normal, near-normal or wetter-than-normal conditions.

While the outlook is for a cooler winter, this does not mean that cold arctic outbreaks are likely. The coolness is primarily caused by the increase in cloudiness. This means that the daily high temperatures tend to be cooler than normal. However, the nighttime lows have a tendency to be slightly warmer than normal because of the increase in cloudiness.

It is very rare to experience temperatures in the low teens along the coast and coastal plain during an El Niño winter. Across the piedmont, single-digit temperatures are very rare. The mountains rarely experience temperatures around zero during an El Niño winter.

It is not unusual for the middle or late spring that follows an El Niño winter to be drier than normal. Thus, water managers are going to have a difficult time regulating reservoirs for an expected wet winter, knowing that from the middle of spring onward there is a good chance Georgia will experience drier-than-normal conditions.

David Emory Stooksbury is associate professor of Biological and Agricultural Engineering at University of Georgia's College of Agricultural and Environmental Sciences.