WunderBlog Archive » Category 6™

Category 6 has moved! See the latest from Dr. Jeff Masters and Bob Henson here.

Heavy rains kill seven in Georgia

By: Dr. Jeff Masters, 1:27 PM GMT on September 22, 2009

Very heavy rains exceeding fifteen inches have soaked the Atlanta, Georgia region over the past two days, triggering widespread major flooding. Record flood levels have been observed on seven rivers and creeks in the Atlanta area, breaking records that had been set as long ago as 1919. In one case, the new flood record (for Utoy Creek near Atlanta), was more that ten feet above the previous record, with the creek still rising. The Chattahoochee River was one of the rivers that rose to record levels, and flood waters from the Chattahoochee crested over the I-285 bridge in western Atlanta, forcing closure of the expressway. At least seven people have been killed, according to ajc.com, with at least six people still missing.

Figure 1. Radar estimated rainfall for the Atlanta, Georgia region ending on September 22. More than 15 inches (white colors) had fallen in and around Atlanta.

A list of the records set so far:

Noonday Creek near Woodstock 19.66 ft 21/530 PM, old record 16.30 ft (07/11/2005)

Nickajack Creek at Mableton 19.30 ft 22/215 am, old record 16.60 ft (07/11/2005)

North Fork Peachtree Creek at Atlanta 18.07 ft 21/715 PM, old record 17.70 ft (09/16/2004)

Utoy Creek near Atlanta 27.04 ft 22/715 am, old record 16.86 ft (05/06/2003)...still rising

Chattahoochee River at Whitesburg 29.58 ft 21/1015 PM, old record 29.11 ft (12/11/1919)

Suwanee Creek at Suwanee 14.30 ft 21/645 PM, old record 12.04 ft (10/05/1996)

Yellow River at Lithonia 25.50 ft 22/515 am, old record 17.53 ft (05/07/2003)... nearly steady

Yellow River near Conyers 20.80 ft 22/730 am, old record 16.36 ft (07/08/2005) below Milstead...still rising

Chattahoochee River at Franklin 28.71 ft 22/715 am, old record 28.40 ft (12/15/1919)...still rising

The strong flow of moist air from the southeast that fueled the heavy rains has diminished today, and no widespread heavy rains will affect northern Georgia over the next few days. However, there will be some scattered thunderstorms in the region the next two days that will dump heavy downpours over local areas, and these thunderstorms will keep flood waters from receding much along some flooded rivers and creeks. It is possible that some additional moisture from the remains of Hurricane Fred will affect northern Georgia and South Carolina Wednesday and Thursday, boosting rainfall totals from these scattered thunderstorms.

Figure 2. AVHRR visible satellite image of Hurricane Hugo taken on September 22, 1989. Hugo was over Ohio at this time, and had finally been declared extratropical.

Twenty years ago today
Hurricane Hugo plowed through the center of South Carolina on September 22, 1989, reaching the North Carolina border 140 miles inland by 8am EDT. Amazingly, Hugo remained at hurricane strength for its entire passage through South Carolina--a full eight hours. The hurricane caused massive damage to forests, buildings, and power lines along the way, killing thirteen South Carolinans in total. Charlotte, North Carolina, over 200 miles inland, and a place of refuge for many South Carolinans that fled the storm, received sustained winds of 69 mph from Hugo--just below the 74-mph threshold of hurricane strength. Hugo turned northwards and roared through Virginia, where it killed six people, then into West Virginia and Ohio, where it was finally declared extratropical at 2pm EDT on the 22nd. The hurricane claimed its final victim near Buffalo, New York, when winds from Hugo toppled a tree onto a motorist.

In all, Hugo did $7 billion in damage to the continental U.S., and $10 billion over its entire path ($17.6 billion in 2009 dollars), making it the most costly hurricane ever at that time. The final death toll was 56.

Figure 3. Maximum wind gusts recorded from Hurricane Hugo of 1989. Wind gusts in excess of 80 mph (green hatched areas) were recorded all the way to the North Carolina border, 140 miles inland. Image credit: National Hurricane Center.

There are no threat areas in the Atlantic to discuss today, and none of our reliable computer models are forecasting tropical storm development over the next seven days.

Jeff Masters

Suwanee Creek Greenway flooding
Suwanee Creek Greenway flooding


The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.