As powerful storms like Helene head towards the U.S., meteorologists utilize a five-category system to convey the severe implications for people in its path.

This system, known as the Saffir-Simpson Hurricane Wind Scale, classifies hurricanes based on their maximum sustained wind speeds, which ranges from 74 to 157 mph and above.

However, it’s crucial to understand that this scale does not account for other potentially lethal hurricane risks like storm surges, heavy rainfall, flooding, and tornadoes. These factors necessitate that residents take protective measures, such as evacuating areas at risk of storm surges.

Hurricane Helene is currently moving towards a landfall on the Florida Gulf Coast scheduled for Thursday, with wind speeds expected to rise in the coming days. As the storm strengthens, it will ascend the official hurricane wind scale, which ranges from 1 to 5.

What is the Saffir-Simpson Hurricane Wind Scale?

The Saffir-Simpson scale correlates wind speeds with examples of the type of destruction and impacts those winds could have in the USA. Generally, the amount of damage increases by about four times with each higher category.

This scale was created by structural engineer Herbert Saffir in 1969 as part of a United Nations initiative. Meteorologist Robert Simpson later refined it in the early 1970s, making it a vital tool for notifying the public about the potential effects of hurricanes with various intensities, according to the National Hurricane Center.

What impact could Helene have in Florida?

The actual damage caused by Helene will be determined by where it makes landfall and how its other effects such as flooding, storm surge, and tornado activity develop. Nonetheless, its wind speed and hurricane category at landfall will greatly influence power outages and structural damage.

A Wednesday update from the National Hurricane Center forecasts the storm hitting land Thursday night as a Category 3, with winds around 125 mph—just 4 mph shy of reaching Category 4 classification. Meanwhile, AccuWeather predictors believe Helene could strengthen to Category 4 while in the Gulf.

If it indeed strikes as a Category 4 hurricane, it would be anticipated to inflict “catastrophic” destruction. The National Hurricane Center indicates that Category 4 storms can severely damage well-built homes, potentially causing them to lose roofs and walls. Most trees would be broken or uprooted, and power poles would be knocked down.

“Power outages may last for weeks to even months. A major portion of the area could become uninhabitable for an extended period,” warns the hurricane center regarding Category 4 storms.

Meanwhile, a Category 3 hurricane, although less powerful, still poses a significant threat. The center cautions that “electricity and water could be unavailable for several days to weeks following the storm’s passage” for these storms.

What classifies a major hurricane?

While all hurricanes can produce dangerously high winds, those classified as Category 3 and higher are termed major hurricanes. These storms can lead to extensive to catastrophic destruction and loss of life. All hurricane categories have the potential to create deadly storm surges, rainfall-driven flooding, and tornadoes.

What are the 5 categories of hurricanes?

Category 1 hurricane: 74-95 mph Very dangerous winds will cause some damage: Well-constructed homes may sustain damage to roofs, shingles, siding, and gutters. Large branches may break, and trees with shallow roots could be uprooted. There will likely be considerable damage to power lines and poles, leading to outages of a few days to several days.

Category 2 hurricane: 96-110 mph Extremely dangerous winds will result in significant damage: Strongly constructed homes could endure major roof and siding damage. Many shallow-rooted trees may snap or be uprooted, blocking numerous roads. Near-total power loss is likely, with outages potentially lasting from several days to weeks.

Category 3 hurricane (major): 111-129 mph Devastating damage is expected: Well-built houses may suffer major damage or loss of roof decking and gable ends. Many trees will likely be snapped or uprooted, obstructing numerous roadways. Electricity and water services will be unavailable.

In the days to weeks following the storm’s passing, significant impacts can be expected.

Category 4 hurricane (major): 130-156 mph Expect severe destruction: Strongly constructed homes may suffer major damage, potentially losing most of their roof and/or some exterior walls. Most trees are likely to be snapped or uprooted, and power lines will fall. This can lead to isolation of neighborhoods due to fallen trees and power poles. Power outages might persist for weeks or even months, rendering most areas unlivable for an extended period.

Category 5 hurricane (major): 157 mph or higher Expect catastrophic destruction: A significant number of framed structures will be obliterated, experiencing total roof failure and wall collapses. Many trees and power lines will fall, isolating communities. Power disruptions could last for weeks or months, and most regions will be uninhabitable for an extended time.

How frequently do each category occur?

Category 1 hurricanes are the most frequent, with as many as seven occurring annually, as stated by Fox Weather. In contrast, there are typically only three Category 3 hurricanes each year.

The rarest are Category 5 hurricanes, with only four recorded landfalls in U.S. history, according to Weather.com.