After six years of above average rainfall, Chattanooga rainfall was nearly 8 inches below normal last year

Last year was Chattanooga's driest in seven years, with rainfall nearly 7.7 inches below normal.

After six years of above-average rainfall in Chattanooga, the National Weather Service said 47.24 inches fell in Chattanooga during 2023, down from the 58.25 inches of rain the previous year. But even with the drier weather, Chattanooga still got more rainfall last year than most of the country and was well above the record low reached in 2007, when less than 31 inches of rain fell across the Tennessee Valley in the worst drought in the 130 years of recorded data.

David Hotz, a senior forecaster with the National Weather Service in Morristown, Tennessee, said most of the shortfall in precipitation last year came during an exceptionally dry September and October.

"Most of the year was fairly typical for rainfall levels before September, and by mid-November, we started seeing above-average rainfall," Hotz said in a telephone interview. "There were really just a couple of exceptionally dry months last year. The storm track during that period went to the north of us, and we were in this area of high pressure systems with dry air masses that kept us from getting any moisture."

(READ MORE: Drought deepens across Chattanooga region)

Last year was also slightly cooler than normal with an average temperature in Chattanooga during all of 2023 of 63.7 degrees Fahrenheit, or 1.81 degrees below normal, Hotz said.

Across the Tennessee Valley, rainfall averaged 48.7 inches for all of 2023, which was about 4% below normal, according to the TVA river forecast center in Knoxville that monitors rainfall and controls TVA's network of 49 dams in TVA's seven-state region. Runoff into TVA reservoirs totaled 17.7 inches last year, which was about 80% of normal for the year but still more than double the 2007 amount.

"This is the first time we've been below normal since 2016, but we were able to transition last fall to a more conservative approach to the water releases in our reservoir operations and currently the storage in our reservoirs is actually about 10% above normal," Darrell Guinn, senior manager of TVA's river forecast center, said in a phone interview Wednesday. "We wanted to make sure we have the flexibility to be able to operate the system for the multiple purposes served by our river system."

(READ MORE: Local history: One-fifth of city under water in '73 flood)

TVA was created in 1933 to harness the power of the Tennessee River and promote river navigation, water quality and recreation while limiting flood damage in the Tennessee Valley. The Tennessee River and its tributaries are also a major source of drinking water for the 10 million people who live in the TVA region.

Hotz said TVA didn't have any major flooding events last year, but TVA spokesman Scott Fiedler said TVA dams helped avert $8 million of flood damages in Clinton, Tennessee, last spring.

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After six years of above average rainfall, Chattanooga rainfall was nearly 8 inches below normal last year

With less rainfall, hydroelectric power generated at TVA's 29 power-producing dams was down about 9% last year, cutting the share of power delivered by hydroelectric generators to 8% of TVA's total portfolio compared with 10% the previous year.

After drizzling rain Wednesday, Hotz said the rain is forecast again this weekend across the Tennessee Valley and near normal precipitation levels are forecast for the next couple of weeks in the Tennessee Valley.

Contact Dave Flessner at dflessner@timesfreepress.com or 423-757-6340.