Despite the forecast for rain, runners are gearing up,

Race unlikely to be called off — unless lightning is a factor.

Bill Thorn isn’t afraid of any rain.

“It’s just all in your mind,” said the Landmark Christian track coach, who is the only person to run in all 43 The Atlanta Journal-Constitution Peachtree Road Races.

The 82-year-old Thorn, who intends to extend his streak to 44 Peachtrees on Thursday, likely will be able to put his mindset into practice. The National Weather Service’s fore- cast Tuesday afternoon called for a 100 percent chance of rain for Thursday morning, and the service issued a flashflood warning for all of north and central Georgia until Fri- day morning, including a 10kilometer stretch of pavement from Lenox Square to Piedmont Park.

For Thursday morning, “It’s looking pretty soggy, pret- ty damp,” NWS meteorologist Ryan Willis said.

So long as the weather involves only precipitation, the race will go forward for the field of 60,000.

“You’re probably going to get wet,” race director Tracey Russell said. “Just be prepared for that.”

Russell encouraged runners to leave umbrellas at home as a safety precaution.

A small sampling of runners at the race expo at the Georgia World Congress Center indicated that rain won’t be much of a concern.

“It’ll be fun either way,” Daniel Wengel of Peachtree City said.

However, the threat of lightning on race morning — Willis called it a definite possibility — has race organizers on alert. Because of the rain, the Atlanta Track Club has set the race to the yellow “moderate alert level,” which is defined as less than ideal conditions with recommended actions to slow down and be prepared for worsening conditions.

Never a matter of light concern, the possibility of lightning requires particularly prudent decisionmaking for Peachtree officials, given that runners will be in open areas, and at the start area nearby metal fences help funnel runners to their appropriate starting groups.

Russell said contingency plans are in place for lightning. Cancellation and delaying the race are possibilities. ATC spokesman Tracy Lott said she could not speak to the possibility of postponing the race. Logistically speaking, postponing would be, at the least, difficult. The 60,000-person race, the largest 10K in the world, also brings together thousands of volunteers and this year, in the wake of the Boston Marathon bombings, will have protection provided by city, state and federal agencies.

The race, first run in 1970, has never been canceled. The last time the race was run in the rain was in 1994, a fairly remarkable run given the late-afternoon and evening summer rains that have long seemed to be something of an Atlanta tradition.

Leading to the race, race organizers will follow the weather. Should officials make decisions that affect runners, the track club will send out alerts via text message and email (registrants provided contact information in their application), on the race website (peachtreeroadrace.org) and via its social media outlets.

Lott said that there is not a specific time by which race officials will make a decision.

“It’s all going to be contingent on whatever the situation is,” she said.

Once runners arrive for the race start in front of Lenox Square in Buckhead, a public-address system can communicate with the thousands of runners who will pack nearby streets as they gather to run. There is also a P.A. system at the race finish area in Piedmont Park.

Warning flags, instituted last year, will be set up at the start and the finish and at water stops to advise runners on race conditions. They are green (good conditions), yellow (less than ideal), red (potentially dangerous) and black (extreme and dangerous/event canceled).

Under the red flag, runners are cautioned to slow down, observe course changes, follow official instruction and consider stopping. A black flag recommends that participants stop and follow official instruction.

The race, which will be the last under Russell’s direction before she takes a job as CEO of the Los Angeles Marathon, could require the utmost of her managerial skills. Fans attending the race are encouraged to leave bags at home.

More areas will be restricted to race workers and volunteers. City, state and federal agents will direct operations from a joint-command center.

The city and the track club can only hope that a little rain is the most severe of the challenges.

“We just want to get everyone home safely,” Mayor Kasim Reed said. “That’s my goal.”