Summertime storms can be very unfair – they can bring torrential rainfall and high winds to a select few communities, while leaving everyone else bone dry for weeks. This has allowed much of northeast Alabama to fall into the ‘abnormally dry’ category on the US Drought Monitor.
What that tells us is pretty limited: abnormally dry means that the conditions are short-term, and still too mild to be impacting the local hydrology (things like well levels, rivers, and watersheds). We have other ways of viewing dry conditions though, which can help us determine how badly some of us need rainfall.
The first way is to use the Palmer Drought Index, which measures dryness using both temperature and precipitation data. This is useful because high temperatures can increase evaporation of moisture from the soil and from plants themselves via evapotranspiration. On the current Palmer Drought Index, northeast Alabama is considered to be under moderate drought – which would require 7-8 inches of rain to end.
The Palmer Drought Index is typically used to gain better perspective on a long-term drought, but Alabama’s drought conditions are still short-term.
During a short-term drought, we can get a better sense of how severe it is by looking at soil health. To do this we have the Lawn and Garden Index.
The Lawn and Garden Index is easy to understand: it measures the soil’s ability to maintain a healthy lawn or garden. Soil needs more moisture during different parts of the year, with summer requiring steady rainfall to maintain the plants that did most of their growing and blooming during the spring. Right now, most of northeastern Alabama is in the red – meaning the soil is too dry to maintain healthy lawn or garden without watering.
The takeaway is this: The drought conditions over Northeast Alabama are not long-term or severe at this point, but it is bad enough that you’ll need to be watering to keep vegetation healthy.
A new US Drought Monitor is released each Thursday, and you can always check the most recent release here: WHNT latest drought monitor