Volume 4, Number 17, April 2013
There have now been two relatively quiet Aprils since the turbulent April of 2011. Storm and tornado damage in Alabama this April were light, and the rain that fell helped pull the state almost completely out of a drought that lasted almost three years.
The U.S. Drought Monitor published Thursday shows that 65 of Alabama's 67 counties have no sign of drought. Only Mobile and Baldwin counties remain in the "abnormally dry" category.
Before that, the last time the state had so little sign of drought was the week of June 29, 2010. But there is an old saying here that Alabama is never more than a week from a drought, which is true because the soil in much of the state has poor water holding capacity so water drains off quickly. The summer of 2010 is a case study in how quickly the water situation can deteriorate.
The June 29, 2010, Drought Monitor showed 100 percent of Alabama in normal conditions. No drought. Nothing abnormally dry.
Then the rain stopped. By the time the next Drought Monitor was published one week later on July 6, almost half of the state was "abnormally dry." By August 1 more than a quarter of Alabama was in the first stages of drought. And by Sept. 21, 2010, 99.85 percent of the state was either abnormally dry or in some level of drought.
Unfortunately, these wet/dry spells are normal for us. I hesitate to call them "cycles," because that might imply a normal up and down, wet or dry cycle, and that is not the case. We can’t predict these events. While there are large-scale patterns that have an impact on our weather — such as El Niños and La Niñas in the Pacific Ocean, and long-lived pressure ridges that can shift the normal flow of weather — more often we are in the sway of smaller, short-lived features.
We had some good soaking rains in April, but the only cause we might find if we go looking for one was a high pressure ridge in the Pacific Northwest that seemed to be favorable for the formation of weather fronts here. The downside of that pattern is that Northern California’s record dry spell (which began in January) continues.
If we are fated to have a relatively normal, relatively wet spring and summer growing season, now might be an excellent time for farmers around the state to investigate the benefits and challenges of irrigation. If you filled out a state income tax form this spring, you might have noted the state's new credit for buying and installing irrigation systems, and the ponds to support them. Your state climatologist and other UAH colleagues, led by Dr. Richard McNider, provided key input into the bill that created that credit.
Under normal circumstances, Alabama is blessed with an abundant supply of water. That is not universally the case in other states. The water problems and the potential long-term return to "normal" dry conditions in western states have been widely reported and discussed.
But even Georgia is dealing with a problem as Atlanta continues to grow and its water sources do not. In an interesting variation of a plan promoted by the Alabama Irrigation Initiative, Georgia is discussing the possibility of pumping excess winter runoff into underground storage so it can later be pumped for use during dry spells for Atlanta and its suburbs.
If the drought is behind us, this might be an excellent year to elevate the conversation about irrigation so we might start to prepare ourselves for the next drought, which unfortunately for Alabama is never more than a week away.
- John Christy