July rainfall: Average is a relative term

If we’ve learned one thing about rainfall at the sub-basins in 2015, it’s that it is anything but average.

July’s observed rainfall fell in line with the Rainfall Chart_July2pattern established by previous months this year, where the odd numbered months fell short and even numbered months surpassed the averages at each of the sub-basins.

While there is nothing impressive about receiving three inches of rain in 31 days (Hartwell: 3.1; Russell 3.2; and Thurmond: 3.6), especially when the sub-basins average 5.2, 4.3 and 4.3 inches, respectively, a closer look at how those three inches were dispersed provides support for the “every little bit counts” mantra.

At Hartwell, the wettest day of the month was July 3, which, after raining most of the day, netted six-tenths of an inch. Similarly, the 48-hour period from July 2-3 at Russell and Thurmond garnered 1.7 and 2 inches, respectively, more than half of each sub-basin’s total for the month.

Throughout the rest of the month, the sub-basins basked in the early- to late-evening mist, which rarely exceeded three-tenths of an inch.

The chart shows hourly rainfall across the Hartwell sub-basin in July. The green highlights indicate rainfall.

The chart shows hourly rainfall across the Hartwell sub-basin in July. The green highlights indicate rainfall.

And though these miniscule amounts combined to push the observed rainfall over three inches at each sub-basin, they left much to be desired, especially considering just two years ago in July Hartwell received more than 13 inches, with Russell and Thurmond hovering around 10 inches.

Yet at the same time, these numbers definitely could have been worse.

Hartwell didn’t even top three inches in July for six straight years between 2006-2011; and Thurmond and Russell shared similar struggles between 2009-2011 (Russell was the star performer when it squeaked over that bar in 2009 by posting 3.14 inches).

So as summer winds down and students head back to school with high marks on their minds, is expecting the sub-basins to just be average too much to ask for? Here’s to putting hopes in August.

~ Jeremy S. Buddemeier, public affairs specialist

About U.S. Army Corps of Engineers Savannah District

The U.S. Army Corps of Engineers Savannah District oversees a multimillion dollar military construction program at 11 Army and Air Force installations in Georgia and North Carolina. We also manage water resources across the Coastal Georgia region, including maintenance dredging of the Savannah and Brunswick harbors; operation of three hydroelectric dams and reservoirs along the upper Savannah River; and administration of an extensive stream and wetland permitting and mitigation program within the state of Georgia. Follow us on Twitter @SavannahCorps and on Facebook.com/SavannahCorps
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