Madison City Stadium, the site of Donald Trump's rally on Sunday. (Bob Gathany/bgathany@al.com)

The Donald Trump rally, which is expecting to squeeze roughly 20,000 people into a high school football stadium in Madison on Sunday, is creating a logistical nightmare for Madison police.

"I don't think you could have picked a worse location for this number of people," Maj. Jim Cooke with the Madison Police Department told AL.com on Friday afternoon.

Cooke said the police department has been in meetings throughout the day Friday trying to prepare for a wave of supporters to see the frontrunner for the Republican presidential nomination.

The rally is scheduled for 4 p.m. and gates open at 2 p.m. at Madison City Stadium in a city with a population of 47,000.

Cooke said the stadium has a seating capacity for 5,000 people, has never has more than 8,000 for an event and only about 1,000 parking spaces. The majority of those parking spaces will be dedicated to handicapped parking.

Police are planning to use off-site parking, including at Bob Jones High School three miles to the north, as well as parking at the abandoned Intergraph buildings just south of I-565. Cooke said the city has secured buses to transport people parking off-site to the stadium.

"I'm about as frustrated as I can get," Cooke said. "I never imagined that I would be notified at 10 minutes after 5 on Thursday afternoon that we needed to plan for an event that takes three weeks to properly plan. We'll figure it out. We've got a lot of great people here and we'll do the best we can with the mission we've got.

"We've just never had that size of an event here before. Logistically, the way that's laid out over there, I just can't tell you what's going to happen if you a crowd of 20,000 people (shows up). I just don't have a clue."

The event was originally scheduled to be held at the AAL USA Inc. hangar on Wall-Triana Highway adjacent to Huntsville International Airport.

That plan was scrapped on Thursday because of the surging number of people who registered online for the free tickets to the rally.

More than 20,000 people have registered online to attend the Trump rally.

"They don't really know," Cooke said of Trump organizers regarding the crowd size. "They believe that approximately 20,000 people have obtained tickets but I don't think anyone knows or has any way of knowing just how many people will show up."