The blistering power of the storm — the second most powerful ever recorded in the Gulf of Mexico — prompted calls for a new Category 6 designation.

"This is nothing short of astronomical," Florida meteorologist Noah Bergren said as Milton reached sustained winds of 180 mph and "gusts 200+ mph."

"I am at a loss for words to meteorologically describe to you the storm's small eye and intensity," he marveled.

"This hurricane is nearing the mathematical limit of what Earth's atmosphere over this ocean water can produce."

After forming as a Category 5 storm, Milton on Tuesday was downgraded to a Category 4 after hitting Mexico's Yucatan Penninsula with a glancing blow. By Tuesday night, it was back to Category 5 again as it churned toward Florida's gulf coast, putting millions of lives at risk.

After forming in the Gulf of Mexico, Milton rapidly accelerated from a tropical storm with 60-mph winds Sunday morning to a deadly Category 5 hurricane by Monday with sustained winds of 180 mph — exhibiting an incredible trebling of power in only 36 hours.

If the hurricane reached winds of 192 mph, it would have surpassed a rare threshold that just five storms have reached since 1980, USA Today reported.

Its exceptional intensity has prompted calls from some meteorologists to expand the Saffir-Simpson Hurricane Wind Scale to include a new Category 6 for hurricanes.

While no such official category exists, professor Michael E. Mann tweeted that "Milton might have actually breached the 192 mph 'Cat 6′ cutoff."

Michael Wehner, a climate scientist at the Lawrence Berkeley National Laboratory, and Jim Kossin, a retired federal scientist and science adviser at the nonprofit First Street Foundation, co-authored a study published earlier this year exploring whether there should be a new category for hurricanes.