Rainfall and average high temperatures
June 2013: 6.38 inches of rain, average high of 84 degrees
July 2013: 11.8 inches of rain, average high of 84 degrees
August 2013: 8.8 inches or rain, average high of 82 degrees
June 2014: 1.76 inches of rain, average high of 86 degrees
July 1-15, 2014: 1.66 inches of rain, average high of 88 degrees
Source: National Weather Service
This time last summer, Hall County residents were repeating a famous refrain from classic rock band Credence Clearwater Revival: “Who will stop the rain?”
Nearly 27 inches of rain fell in Gainesville between June and August last year, washing out roads, closing parks and costing local governments millions of dollars.
“We had a persistent trough of low pressure in 2013 that promoted development of long-lived and intense rainfall,” said Thomas Mote, a professor in the Department of Geography at the University of Georgia and a specialist in hydro-climatology.
But as wet as the region was last summer, it’s equally dry in 2014.
“This year, the upper-level trough has set up shop mainly just to the east of Georgia,” said Victor Murphy, climate services program manager for the National Weather Service Southern Region. “This positioning tends to inhibit the flow of deep low-level moisture from the Gulf of Mexico and also promotes some sinking motion aloft. Both of these combined tend to be conducive to a drier pattern.”
According to the National Weather Service, less than 3.5 inches of rain fell in Gainesville between June 1 and July 15, about half the average amount. Rainfall in June was about 2.6 inches below average.
For the same period last year, the area received more than 13 inches of rain, better than double the average.
“Summer of 2014 has been more typical, with occasional persistent rain and scattered afternoon thunderstorms,” Mote said.
Of course, it’s not only been drier, but hotter, too.
The average high temperatures for June and July last year were 84 degrees.
But in 2014, the average high for June was 86 degrees and for July is 88 degrees so far.
The United States Drought Monitor reports abnormally dry conditions in South Hall and counties across the Atlanta metro region.
The extremes in weather this summer and last, however, are not specifically related to climate change, according to experts.
“I don’t believe you can easily draw that connection,” Mote said. “A number of scientists have made the argument that extremes in weather have been driven by changes in the Arctic, and there is substance to those arguments.”
Instead, other factors are at play, though no less complex.
Bill Murphey, chief meteorologist and state climatologist with the Georgia Environmental Protection Division, said North Georgia was transitioning out of a period of drought in early 2013 as a result of La Nina weather patterns, which produce cooler-than-average water temperatures in the Pacific Ocean.
Jet streams pushing large pockets of moist air from the Gulf of Mexico into the region came as a more neutral weather cycle emerged, and the deluge was on.
Now Hall County residents are asking, “Have you ever seen the rain?”
But with the Atlantic hurricane season kicking into full gear after the first named storm brushed the Outer Banks of North Carolina earlier this month, could North Georgia see its dry, hot summer spared a little moisture?
Forecasters at Colorado State University have predicted a relatively calm season, suggesting just three tropical storms will reach hurricane-level intensity.
Since 1950, an average of seven hurricanes have formed in the Atlantic Ocean between June 1 and the end of November.
Gainesville Public Works Director David Dockery said he is prepared for any precipitation, flooding and damage the region could experience resulting from hurricane-related weather.
“Last year’s abnormally wet July didn’t have anything to do with tropical weather,” Dockery said, “but the heavy thunderstorms certainly wreaked havoc in many areas of the city. ... So far, this summer has been much drier than last and from what I understand, the seasonal forecast for the area is for normal to slightly drier conditions.”
But the neutral weather cycle the region has been experiencing may give way to a moderate El Nino pattern, which corresponds to warmer ocean temperatures, in late summer or early fall, Murphey said.
And the National Weather Service is warning that other factors could bring some wet weather in the coming days.
“There currently is a rather strong upper-level trough over Texas that is forecast to move slowly east,” Murphy said. “At this time, it would appear that this feature will bring widespread 1 to 2 inches of rain to North Georgia during the Sunday-to-Tuesday time frame. Some locations could see up to 4 inches of rain. This event should go a long way toward mitigating the recent dryness.”