DES MOINES, Iowa (AP) -- Meet director Brian Brown spends 51 weeks each year working to make sure the Drake Relays go as smoothly as possible.

The only thing Brown can't control is the weather, and the forecast this year looks terrible. The 103rd Drake Relays, which begin in earnest on Thursday, will likely be hampered by rain and temperatures in the low 50s on Friday and Saturday. The weather could force athletes hoping to compete at the London Olympics to sit out to avoid potential injuries.

Brown is hopeful that a packed house and the aura associated with one of the nation's top track and field meets will push those athletes to compete.

"For those who, it might be their first time, they'll think, `Wow. I can't believe all these people are still here. I can't believe all these people that competed before me competed at such a high level. I better get my act together and follow suit,"' he said.

It'll be a shame if the weather thins the fields for Saturday's marquee events.

As always, hurdler Lolo Jones will be the headliner in her hometown.

Jones, a four-time Drake Relays champion in the 100-meter hurdles, makes it a point to run here every year. But the hurdler best known for her agonizing spill in the finals in Beijing four years ago has lost three straight Drake finals, though she did win the USA Outdoor title in Des Moines in 2010.

Drake also received a late commitment from decathlete Bryan Clay, who is three months away from going for a third straight medal at the Olympics.

Clay won gold four years ago and silver in Athens in 2004 and will be the favorite to break the meet record of 8,198 points set by Kip Janvrin in 1996.

Olympic hopeful Wallace Spearmon Jr. leads the field for the men's 200 meters. Spearmon is a two-time U.S. outdoor champion in the event and ran a world-leading 19.95 seconds last month - a time that would break the meet record held by Michael Johnson.

Jenny Simpson, the reigning world champion in the 1,500 meters and one of the favorites to win gold in London, will open her outdoor season at Drake this weekend. Simpson, who grew up in nearby Webster City, Iowa, won the meet in 4:09:56 in 2011.

Two-time Olympic silver medalist Terrance Trammell tops the field for the 110 hurdles, while Puerto Rico's Javier Culson is ranked second in the world in the 400 hurdles. American up-and-comer Queen Harrison, at 23, leads the field for the women's 400 hurdles.

As usual, the field events might boast more overall talent.

High jumper Chaunte Lowe, the four-time U.S. outdoor champion, will try to break the American record of 6 feet, 8.75 inches she set at the USA Outdoor meet in Des Moines two years ago. Kara Patterson also set an American record during the national outdoor meet in 2010 with a javelin throw of 218-8, and she'll be seeking her third meet title in as many tries.

One of the more unique aspects of the Drake Relays is the appreciation fans have for the shot put, which was moved inside Drake Stadium. Four of the world's top eight shot putters will compete, led by seven-time meet champion Christian Cantwell.

More than 1,200 prep athletes and some 2,500 collegians will also compete. That includes the University of Florida, which finished third in the NCAA Outdoor meet in Des Moines last summer and will be getting an early look at Drake Stadium ahead of June's return of the NCAA meet.

The Gators' 400-meter relay team, led by former football star Jeff Demps, will attempt to break the meet mark of 38:96 set in 1983.

Though Brown spent the past year putting together the best field he could, he can't force them to compete if Mother Nature makes doing so a risk. Still, Brown knows bad weather doesn't necessarily translate to a bad meet.

"If it's rain, I'm OK with that. If it's sunny, that's good. I'll take it, but it'll be the way it should be for this year and I won't try and fight it. I'll embrace and make the most of it," Brown said.

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