Image source: Universal Orlando.

This is supposed to be quiet season for Central Florida's theme parks, but you won't have a lot of elbow room if you're heading out to Comcast's (NASDAQ:CMCSA) (UNKNOWN:CMCSK.DL) Universal Orlando over the weekend. A Celebration of Harry Potter -- an annual event that is now in its third year -- has been keeping Universal Orlando busy over the weekend. 

The event features movie exhibits, Q&A with the stars from the popular movie series, and generally a place for fans of J.K. Rowling's iconic book series to gather with like-minded souls. 

It's naturally a big moneymaker for Comcast, especially since some of the more compelling festivities require the purchase of premium packages. It's also something that has to be giving Disney (NYSE:DIS) fits. 

Disney is seeing Comcast close the gap in popularity. It's been happening ever since Comcast opened the first phase of The Wizarding World of Harry Potter in 2010, raising the bar even higher a few years later with the ambitious Diagon Alley expansion of 2014. Both of the resort's theme parks now have richly detailed areas dedicated to Potter, complete with high-tech rides and plenty of shops and eateries to milk even more money out of wizard-aspiring muggles. There's even a train -- Hogwarts Express, of course -- that transports guests from one theme park's Potter land to the other. 

It's as close to perfection as a theme park has ever gotten in an expansion, and Disney can't be happy as it sees the turnstiles clicking faster at its biggest rival.

Magic Kingdom 16,640,000  19,332,000 16.2%
EPCOT 10,460,000 11,454,000 9.5%
Animal Kingdom 8,910,000 10,402,000 16.7%
Hollywood Studios 9,100,000 10,312,000 13.3%
Universal Studios Florida 6,000,000 8,263,000 37.7%
Islands of Adventure 5,300,000 8,141,000 53.6%

Data source: Themed Entertainment Association.    

Comcast's theme parks have grown at a faster percentage rate than its larger Disney World counterparts. It's also a material difference in terms of raw head counts. Universal Orlando's two parks have gained more guests in those eight years -- a per-park average of 2.55 million -- than the 1.6 million average gain in patrons at Disney World.

This weekend is just another reminder that Comcast is gaining on Disney. The House of Mouse is working on a response. An Avatar-themed land opens at Animal Kingdom next year. The highly anticipated Star Wars Land at Disney's Hollywood Studios is only in development, but it will take several years before that expansion is complete.

Along the way, Universal Orlando will just keep getting bigger. A King Kong ride and the resort's fifth hotel opens this summer. An on-site water park, Jimmy Kimmel attraction, and a The Fast and the Furious ride open next year. As busy as Disney is in plotting its comeback, Comcast is taking The Fast and the Furious' lead by pressing hard on the accelerator.

Comcast isn't stopping there. It recently revealed plans to purchase parcels of land totaling 474 acres about two miles south of Universal Orlando. That gives it enough room to build at least one more theme park and several more hotels in the future. It may not be ideal to have to expand with so many third-party establishments in the way, but this will increase its visibility along the bustling tourist corridor.

Wingardium Leviosa is the levitation spell in Rowling's Potter universe. Comcast seems to have that charm these days, and Disney needs to find it or fight it before it starts losing ground.