May for Alabama and Tennessee usually brings rain and storms; that rain also typically totals up to be among the wettest months for Huntsville (5.11″ of rain, third-rainiest of the calendar year).
The monthly total shows above-average rainfall (4.98″ is 1.81″ above the 30-year climatology through May 21st), but the landscape tells a different story!
Dr. John Christy, Alabama’s State Climatologist, says of our state’s water cycle:
We’re starting to see the effects of a lack of recent rain in a what-have-you-done-for-me lately time of the year.
The drier it gets, the hotter it gets. A strong ridge overhead through the weekend and most of next week steers the jet stream and any deep tropical moisture away from us; that shuts down the prospects for widespread heavy rainfall in our near future.
It’s been twelve days as of Friday, and most of North Alabama/Southern Tennessee will make it to at least nineteen days without significant rain (more than 0.10″).
So yes, it’s dry. We just aren’t quite to drought just yet.
The lawn and garden index from Dr. Christy shows some spots of serious dryness and some areas where soil moisture is still actually a little higher than normal.
Over the next week, the dry areas likely expand significantly; however, the longer-term outlook from NOAA’s Climate Prediction Center does not anticipate significant, longer-term drought development through the summer as of now.
Although long-term drought appears unlikely, we can find ourselves in ‘flash droughts’
Flash drought refers to relatively short periods of warm surface temperature and anomalously low and rapid decreasing soil moisture.
That could cause some short-term problems for agriculture and for keeping lawns green and gardens growing through the end of next week.
Turning wetter in June
There’s a good chance that our ridge breaks down allowing for the early summer ‘northwest flow’ by the final days of May into early June.
That pattern usually sends multiple waves of storms our direction in Tennessee and Alabama. The American-run GFS model guidance five-day rainfall starts to pick up next weekend through Memorial Day.
Exact details are impossible, but it is totally reasonable to expect at least a half-inch to as much as two inches of rainfall from waves of storms in about 8 to 10 days. It could miss you to the north or south, though. There are no guarantees when it comes to rain in early summertime!