Heat and humidity, thunderstorms with lightning, torrential downpours and flooding, hail, high winds, possibly a hurricane. It may sound like biblical retribution, but it's just summertime in the South and an apt description of what awaits athletes and spectators arriving for the 1996 Olympic Games, which begin today and conclude Aug. 4.
"Atlanta in 1996 will not be like L.A. in 1984," said Sandra Young, a senior branch forecaster with the National Weather Service. "We have a lot more to deal with."
To help the more than 10,000 athletes and 2-million spectators cope, the National Weather Service has mobilized what it describes as one of the most advanced observation and warning networks ever assembled.
The competition in 35 sports will be dispersed over the widest geographic area in the history of the modern Olympics (that is, the past 100 years). The venues stretch from the Ocoee River in southern Tennessee, where whitewater kayakers will compete, to the sailboat races off Wassaw Sound, on the Atlantic Coast near Savannah, 250 miles southeast of Atlanta.
The forecasters, like the athletes, talk of pushing themselves to their limits as they mobilize around the clock to issue rapid-fire predictions for precisely targeted sites. Each sport has its own tightly tailored concerns. For example, the divers at the Georgia Tech Aquatic Center downtown require notification when the winds there will exceed 20 mph. And rowing crews on Lake Lanier, about 40 miles northeast of the city, want to know when winds will blow from the southeast, Young said. Certain lanes would then be sheltered, giving some rowers an advantage over the others.
One of the most weather-sensitive events is the sailing competition, where the U.S. Coast Guard estimates that as many as 1,000 small boats will vie for good viewing positions on the open waters. A special Weather Service team with expertise in marine forecasts will be stationed nearby in a 40-foot trailer inside the Olympic Marina on Wilmington Island, with daily, in-person briefings for officials and sailing teams.
"We have to be both meteorologists and oceanographers," said Steven Rinard of the Weather Service, who is in charge of the Olympic Marina weather outpost. Wind information is obviously critical to sailors. And, for the safety of spectators and support boats, Olympic officials plan to shut down the courses in winds above 25 knots, he said. But he noted that his team will also provide information on tidal currents, which can run as fast as two knots (about 2.3 mph) and can mean the difference between victory and defeat to those who know how to use them.
Perhaps the most challenging weather venue of all is the cycling track at the Stone Mountain Velodrome east of the city, where organizers want to be alerted whenever dew is likely to form on the track, making it slippery and dangerous. "That one's got me a little worried, I confess," said Lans P. Rothfusz, meteorologist in charge of the Olympics Weather Support Office in Atlanta.
He said the biggest general worry, along with the deep South's infamous heat and humidity, is lightning. In the Atlanta area, lightning strikes 800 to 1,000 times per hour on average during a thunderstorm. The city averages 10 storms in July, eight in August. (The average is higher for some of the other Olympic sites.)
On hand to churn out weather information is a cadre of 20 Weather Service meteorologists, plus four from the Canadian Atmospheric Environment Service and two from the Australian Bureau of Meteorology. Most will work at the main office in Peachtree City, south of Atlanta, which is equipped with a massively parallel processing computer on loan from IBM that can perform millions of calculations per second. The others will operate from the marina trailer on the coast.
The Weather Service, working with Olympic officials, has spent years developing and testing the plan. The $900,000 Olympics weather project will benefit all taxpayers, according to Rothfusz, because it provides a full dress rehearsal for the deployment of new forecast tools and techniques nationwide. In fact, the games have served as a catalyst, Weather Service officials say, driving them to speed development of various advanced radar, satellite and automated observation systems as they approach the end of what they consider a historic, almost decade-long, $4.5-billion general modernization. These include finely targeted early warnings of short but potentially catastrophic events such as tornadoes, cloudbursts and flash floods.
To accommodate requests by the Atlanta Committee for the Olympic Games for specific, targeted forecasts, officials said the Weather Service will have to process huge amounts of data at top speed from a variety of sources. But, they add, the new tools should be up to the job. Among the advantages they will have are the following:
Automated observations every 15 minutes (instead of the standard hourly ones) from more than 60 observing sites in Georgia, operated by state agencies and universities.
Three newly deployed buoys taking data around the clock on offshore wind, waves, temperatures and currents off the Georgia coast. The observations will be reported by radio transmissions every 10 minutes (instead of the normal hourly reports). They will supplement data from Savannah Light and several automated weather stations along the coast.
Soundings by weather balloons taken every six hours (instead of every 12 hours), from six locations in the Southeast, to identify patterns in the upper atmosphere that influence surface weather.
High-speed computer simulations that incorporate all the data on existing conditions and predict upcoming weather in unprecedented detail. The runs will be made twice daily by the National Centers for Environmental Prediction in Camp Springs, Md., using a Cray supercomputer. The models plow the data through a complex mathematical formula, Rothfusz explained, and predict from six minutes up to 10 days into the future. "We're fine-tuning the focus," he said. "In the old model, we'd predict "rain over Georgia.' Now we can say, "Two inches of rain downtown but none for the rowing competition at Lake Lanier.' "
The forecasters plan to issue their predictions at three-hour intervals. They even plan to provide an ultraviolet index, localized for each site throughout the games, to help people avoid overexposure to the sun's harmful rays.
Still, there is a limit to what they can do. Young remembers the summer when the remnant of a hurricane parked over Georgia and it rained for days. "God help us," she said, "please don't send us a hurricane this year."