A major storm system that moved into the Southeast during late October brought short-term relief to parts of the region that have suffered from drought conditions since late last year.
The rainfall, however, did little for the long-term outlook, as governors from Alabama, Georgia and Florida met in Washington, D.C., to try and iron out their differences on how to allocate limited water resources within the three states.
According to the U.S. Drought Monitor, a major storm system brought heavy rains to the western portions of the Southeast affected by drought and continued eastward, dropping impressive totals over a large area from the Ohio Valley to the mid-Atlantic region.
From Oct. 23 to Oct. 27, 4 to 6 inches of rain, with locally higher amounts, drenched the area from North Carolina into eastern Pennsylvania and parts of New Jersey. One to 3 inches fell over the southern Ohio Valley and the Tennessee Valley, and this was on top of the earlier heavy amounts.
As a result of the rainfall, the area of drought diminished, with “exceptional” drought conditions giving way to “extreme,” “severe” or better in western Alabama and much of North Carolina. Dryness ended over most of western Kentucky and western Tennessee. Although streamflows and soil moisture improved, reservoirs remained critically low in portions of the drought region, including northern Alabama.
Due to lower rainfall amounts in Georgia, there was little change in the drought status in that state, with exception conditions persisting in the north.
Long-term rainfall deficits remained a factor in the water supply situation in the Southeast, with year-to-date totals at least 16 inches below normal in much of Alabama, central and eastern Tennessee, northern Georgia and western North Carolina, and exceeding 20 inches in northern and central Alabama.
Drought conditions are expected to continue across much of Georgia through spring 2008 and may expand into southeast Georgia by spring, according to David Stooksbury, the state’s climatologist.
A La Niña climate pattern has developed, he says, 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,” said Stooksbury in late October.
The effects of the La Niña pattern differ with its strength, he adds. “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,” he says.
A weak La Niña climate pattern typically brings a warm, dry winter and spring to south Georgia, says Stooksbury. “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,” he says.
Regardless of the strength of the current La Niña, he says, 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.
“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,” he says.
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, says Stooksbury.
“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,” he says.
Meanwhile, the governors of Alabama, Georgia and Florida met in Washington, D.C., recently to try and resolve a dispute over how water resources should be allocated between the three states.
A temporary truce in the long-running tri-state “water wars” was brokered by the Bush administration and the U.S. Department of the Interior. The aim of the agreement is to boost metro Atlanta’s drinking water supply while protecting the drought-stricken communities and industries downstream in Alabama and Florida.
Key points of the agreement are as follows:
• Flow on the Chattahoochee River reduced to bolster Lake Lanier outside of Atlanta.
• Fewer withdrawals from Allatoona Lake to bolster Alabama and Coosa rivers.
• U.S. Fish and Wildlife Service must determine whether changes hurt endangered species.
• Governors agree to meet again in December.
The U.S. Corps of Engineers also agreed to make modifications in its operating plans and hopes to give all states flexibility in the management of their reservoirs, and the three governors agreed to set a Feb. 15 deadline to have all issues in their water dispute resolved.