Milton's journey from a Category 2 storm to a Category 5 on the Saffir-Simpson hurricane scale in just a few hours has forecasters wondering whether the powerful storm could become a Category 6 storm.
The storm developed very strongly and very quickly on October 7 after forming in the Gulf of Mexico, exploding from a tropical storm with a speed of 96 km/h on the morning of October 6 to a Category 5 super typhoon with winds of 289 km/h, accelerating rapidly to 193 km/h in 36 hours.
The rapidly developing storm shows no signs of stopping and will not technically become a Category 6 hurricane as there are currently no Category 6 hurricanes. But it could soon reach the level of a hypothetical Category 6 hurricane that experts have discussed and stirred up debates over whether the Saffir-Simpson scale, which has long been used by the US National Hurricane Center (NHC) to classify hurricane wind speeds from Category 1 to 5, needs to be revised.
Milton was in thin air as it crossed 252 km/h to become a Category 5 storm. But if it reaches 202 mph winds, it would surpass the threshold that only five have reached since 1980, according to Michael Wehner, a climate scientist at the Lawrence Berkeley National laboratory, and Jim Kossin, a retired federal scientist and science advisor at the First Street Foundation.
The two scientists have been studying whether to add a Category 6 hurricane. All five of the 308 km/h typhoons have occurred in the past decade.
Scientists say more and more typhoons are becoming more intense due to record-warming waters in the world's oceans, especially in the Gulf of Mexico and parts of Southeast Asia and the Philippines.
Kossin and Wehner said they are not proposing adding a Category 6 super typhoon to the wind scale but are trying to "report to broader discussions" about the growing risks in a warming world.
The US National Hurricane Center has used the famous five-step Saffir-Simpson scale since the 1970s. The minimum threshold for a Category 5 storm is 252 km/h winds.
Designed by engineer during during during the great depression and revised by former center director Robert Simpson, the Saffir-Simpson scale stops at level 5 because such strong winds will "cause serious disruption no matter how well designed," Simpson said in an interview in 1999.
Kossin noted that the scale for Category 5 storms is becoming increasingly unsuitable over time as climate change is creating more and more unprecedented storms of unprecedented strength.
