The heavy storm currently hitting the East Coast with a wintery mix of rain, snow and wind may ground the famous giant balloons at the 87th annual Macy's Thanksgiving Day Parade. 

Beloved characters like Snoopy and Kermit the Frog may not lift off the ground on Thursday if winds exceed 23 mph and gusts exceed 34 mph, according to city regulations. The rules were put in place after heavy winds at the 1997 parade caused a Cat in the Hat balloon to push over a light pole and seriously injure a spectator. 

As of now, forecasts for Thursday call for sustained winds of 20 mph and gusts of 36 mph, according to USA Today. 

"At this time, it is too early to make any determinations on the flight of the giant balloons," said Macy's spokesman Orlando Veras. "On Thanksgiving morning, Macy's works closely with the NYPD, who, based on real time weather data and the official regulations, determine if the balloons will fly and at what heights."

Ballons have only been grounded once, when bad weather kept them down in 1971. This year's balloons are set to be inflated on Wednesday night. 

Macy's said that each balloon flies at a different height based on weather conditions, ABC News reports. Weather permitting, each will fly at their individual height depending upon wind conditions. 

The parade floats have also been the subject of unlikely controversy. Animal activists plan to line the parade route to protest a SeaWorld float over allegations in a new documentary that the theme parks treat whales poorly. 

SeaWorld says the accusations have "absolutely no basis," and that "the men and women who care for these animals at SeaWorld are dedicated in every respect to their health and well-being."

Additionally, ranchers pulled rocker Joan Jett from the South Dakota tourism float after insisting that the vegetarian and animal-rights supporter should not represent the state, which produces a great deal of beef.  

Macy's has said the parade will not engage in political or social debate or commentary.