Hurricane categories - why they’re useful and where they fall short

Hurricane categories - why they’re useful and where they fall short

WILMINGTON, NC (WECT) - Since the 1950s, meteorologists have categorized hurricane intensity with the Saffir-Simpson Scale. The scale has utility, but it also has many shortcomings. Here, we will refamiliarize you with the Category 1 through 5 Saffir-Simpson Scale. We will also argue why you need to look past a particular storm's cursory category to gauge its true severity.

THE SCALE: A QUICK REFRESHER

Recall that the Saffir-Simpson Scale rolls a single hurricane metric - maximum sustained wind speed - into five categories:

- Category 1 hurricanes feature 74-95 mph winds.

- Category 2 hurricanes feature 96-110 mph winds.

- Category 3 hurricanes feature 111-129 mph winds.

- Category 4 hurricanes feature 130-155 mph winds.

- Category 5 hurricanes feature maximum sustained winds in excess of 156 mph.

Category 2 hurricanes are usually more destructive than Category 1 hurricanes, 3s are usually worse than 2s, etc.

Simple, right? Sure! But, perhaps too simple...

HURRICANES: MUCH MORE THAN WIND

The list of hurricane hazards not included in the Saffir-Simpson Scale is extensive:

- maximum wind *gusts*

- tornado potential

- rainfall potential

- flash flood potential

- river flood potential

- storm surge potential

- size and symmetry of storm

- storm speed and duration

- landfall approach angle

Occasionally, a catastrophic hurricane will sport a deceptively low Saffir-Simpson category. Hurricane Florence did...

FLORENCE: “ONLY A CATEGORY 1”?

History will correctly tag Hurricane Florence of September 2018 as a relatively minimal Category 1 storm since it featured maximum sustained winds of “only” 90 mph at its Wrightsville Beach landfall.

But, across the Carolinas, Florence killed at least 30 people and inflicted more than $20B in damage. And in the Cape Fear Region, Florence will be remembered as one of the worst - if not the worst - hurricanes of all time.

Florence generated...

- a 105 mph wind gust at Wilmington - the Port City’s second highest on record. Stronger than Fran and Hazel...

- brief but violent tornadoes on three consecutive days.

- 23 inches of rain at Wilmington and up to 36 inches near Elizabethtown.

- numerous spells of life-threatening flash flooding.

- record flooding on the Lumber, Cape Fear, Black, Northeast Cape Fear, and other rivers. Worse then Matthew and Floyd...

- damaging storm surge along Topsail Island and even higher surges just to the north around New Bern and Belhaven.

Florence was also a large and excruciatingly slow-moving storm that approached the coast at a particularly perilous 90-degree angle.

BOTTOM LINE: LOOK PAST THE CATEGORY

Florence, like no other storm in Cape Fear Region history, showed how there’s so much more to a hurricane than its Saffir-Simpson category. So please be a savvy weather consumer and, next time a storm threatens, look to your First Alert Weather Team to go past these often deceptive storm labels and into specific, impact-based forecasts! We’ll have you covered!

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