Saffir-Simpson Scale PDF Print E-mail

The Saffir-Simpson Hurricane Scale

 


 

The Saffir-Simpson Hurricane Scale is a classification used for hurricanes. The scale divides hurricanes into five categories distinguished by the intensities of their sustained winds. The classifications are intended primarily for use in measuring the potential damage and flooding a hurricane will cause upon landfall.

Wind speed is the determining factor in the scale, as storm surge values are highly dependent on the slope of the continental shelf, the angle of approach of the hurricane and the shape of the coastline in the landfall region.

Category One Hurricane:

Winds 74-95 mph (64-82 kt or 119-153 km/hr). Storm surge generally 4-5 ft above normal. No real damage to building structures. Damage primarily to unanchored mobile homes, shrubbery, and trees. Some damage to poorly constructed signs. Also, some coastal road flooding and minor pier damage.  Examples of  category 1 hurricanes  are Abby (July 1960) and  Anna (July 1961) which affected southern Belize.



Category Two Hurricane:

Winds 96-110 mph (83-95 kt or 154-177 km/hr). Storm surge generally 6-8 feet above normal. Some roofing material, door, and window damage of buildings. Considerable damage to shrubbery and trees with some trees blown down. Considerable damage to mobile homes, poorly constructed signs, and piers. Coastal and low-lying escape routes flood 2-4 hours before arrival of the hurricane center. Small craft in unprotected anchorages break moorings. Francelia (Sept 1969)was a category 2 hurricane which impacted on southern Belize.  Other notable Category 2 hurricanes Fifi (Sept 1974) which impacted southern Belize and Greta (Sept 1978) which made landfall along the central coast.



Category Three Hurricane:

Winds 111-130 mph (96-113 kt or 178-209 km/hr). Storm surge generally 9-12 ft above normal. Some structural damage to small residences and utility buildings with a minor amount of curtain wall failures. Damage to shrubbery and trees with foliage blown off trees and large trees blown down. Mobile homes and poorly constructed signs are destroyed. Low-lying escape routes are cut by rising water 3-5 hours before arrival of the center of the hurricane. Flooding near the coast destroys smaller structures with larger structures damaged by battering from floating debris. Terrain continuously lower than 5 ft above mean sea level may be flooded Hurricanes  Carmen (Sept 1974)which passed north of northern Belize. Keith (Oct 2000) rapidly intensified to a category 3 within a 24 hour period.



Category Four Hurricane:

Winds 131-155 mph (114-135 kt or 210-249 km/hr). Storm surge generally 13-18 ft above normal. More extensive curtain wall failures with some complete roof structure failures on small residences. Shrubs, trees, and all signs are blown down. Complete destruction of mobile homes. Extensive damage to doors and windows. Low-lying escape routes may be cut by rising water 3-5 hours before arrival of the center of the hurricane. Major damage to lower floors of structures near the shore. Terrain lower than 10 ft above sea level may be flooded requiring massive evacuation of residential areas.  The most notorious category 4 in Belize’s history was Hattie (Oct 1961). More recently Iris (Oct 2001) devastated Placencia, Monkey River and nearby localities in the south.

Category Five Hurricane:

Winds greater than 155 mph (135 kt or 249 km/hr). Storm surge generally greater than 18 ft above normal. Complete roof failure on many residences and industrial buildings. Some complete building failures with small utility buildings blown over or away. All shrubs, trees, and signs blown down. Severe and extensive window and door damage. Low-lying escape routes are cut off by rising water 3-5 hours before arrival of the center of the hurricane. Major damage to lower floors of all structures located less than 15 ft above sea level. Massive evacuation of residential areas on low ground and coastal areas are required. Janet (Oct 1955) is a well known category 5 hurricane that impacted the Corozal district. More recently Mitch (Oct 1998) devastated nearby Honduras and spared Belize from major destruction.. In 2007 Dean (Aug 2007) made landfall just north of Corozal. Winds in hurricane Dean reached 165 kt just before landfall.

 

Saffir-Simpson Hurricane Scale

Category

Wind speed

Storm surge

 

mph
(km/h)

ft
 (m)

5

≥156
(≥250)

>18 (>5.5)

4

131–155
(210–249)

13–18
(4.0–5.5)

3

111–130
(178–209)

9–12
(2.7–3.7)

2

96–110
(154–177)

6–8
(1.8–2.4)

1

74–95
(119–153)

4–5
(1.2–1.5)