Multi-Hazard Mitigation Plan: 05. Tropical Cyclones

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Chapter 5:Hazard Analysis—Tropical Cyclones Table 5-2. Satlir Simpson Scale and damage potential Central Pressure Hurricane Sustained Fastest Peak Gust Approximate Mm of Sea level Mile Speed (over land) Storm Surge Damage Potential(with tropical Pacific amendments) Category mercury at 0 y�rtrd' mph mph Height(ft.) degrees C(32 Pressure degrees F) (inches) Tropical <40 mph <2 ft Virtually None. Some small dead limbs,ripe coconuts,and dead Depression (<64 1rrnMr) 0.61 m) <1008 <29.77 palm fi-ca ds m blown fia trees. Some(agile and tender green leaves (< blown firm trees such as papaya and Meshy broad leaf plants. 40-73 mph Some.Minor damage to buildings of light material. Moderate Tropical 2-3 ft damage to banana trees,papaya trees,and most fleshy crops. Large Storm 979-1007 28.91-29.74 (64- (0.61-0.91ni) dead limbs,ripe coconuts,many dead palm fronds,some green 117km/hr) leaves,and small branches blown fiam trees. Significant.Corrugated metal and plywood stripped from poorly constructed or termite-infested structures and may become airborne. Some damage to wood roofs.Major damage to banana trees,papaya 74-95 mph trees,and Ileshy crops. Some palm fronds tarn Hour the crowns of 1 980-992 28.94-29.30 (118-153 67-88 82-108 4-5 ft most types of paten trees,many ripe coconuts blown from coconut kmMr) (1.22-1.52m) palms. Some damage to poorly constructed signs.Wooden power poles tilt,some rotten power poles break,termite-weakened poles begin to snap. Low-lying coastal roads inundated,minor pier darnage,some small craft in exposed anchorage torn from moorings. Moderate. Considerable damage to structures made of light materials.Moderate damage to houses.Exposed banana trees and papaya trees totally destroyed,10%.-20%defoliation of trees and 96-110 mph shrubbcry. Many palm fronds crimped and bent through the clown 6-8 ft 2 965-979 28.50-28.91 (178-209 SS-I 10 108-13U f ococonut palms and several green fronds tipped hour palm trees; kin/hr) (1.83-2.44 in) some trees blown down.Weakened power poles snap.Considerable damage to piers;marinas flooded.Small craft in unprotected anchorages torn from moorings.Evacuation from some shoreline residences and low-lying areas required. Extensive.Extensive damage to houses mid small buildings;weakly constructed and termite-weakened house heavily datuaged or destroyed;buildings made of light materials destroyed;extensive damage to wooden structures.Major damage to shrubbery and trees; 111-131 9-12 ft up to 50%of palm fonds bent m blown off;numerous ripe and many 3 945-964 27'91 nnph 110-136 130-156 (274-3.66 green coconuts blown off coconut palms;crowns blown off of palm 28.47 (178-209 trees;up to 10%of coconut palms blown down;30%-5O% km/hr) m) defoliation of many trees and shrubs.Large trees blown dowm.Many wooden power poles broken or blown down;many secondary power lines downed.Air is frill of light projectiles and debris;poorly constructed signs blown down.Serious coastal flooding;larger structures near coast damaged by battering waves and floating debris. Extreme. Extreme structural damage;even well-built structures heavily damaged or destroyed;extensive damage to non-concrete failure of many roof structures,window frames and doors,especially unprotected,non-reinforced ones;well-built wooden and metal structures severely daniaged or destroyed.Shrubs and trees defoliated;up to 75%of palm fronds bent,twisted,or bloom off. 131-155 13-18 ft Many crowns stripped from paten trees;nunerous green and virtually 27.17- mph all ripe coconuts blo�nm from trees;severe damage to sugar cane; 4 920-944 P 136-16y 156-191 1296-5.4y 1 b 27.88 (210-249 large Gees blown down;bark stripped from trees;most standing trees km/hr) ui) are void of all but the largest branches(severely pruned),with remaining branches stubby in appearance;hunks and branches are sandblasted.Most wood poles downed/snapped;secondary and primary power lines downed.Air is full of large projectiles and debris.All signs blown down.Major damage to lower floors of stmctm-e,due to flooding and battering by waves and floating debris. Major erosion of beaches. Catastrophic. Building failures;extensive or total destruction to >155 mph norrcoricTete residences mid industrial buildings;devtxting damage >IS ft to roofs of buildings;total failure of non-concrete reinforced roofs. 5 <920 <27.17 (>250 (>5.49 on Severe damage to virtually all wooden poles;all secondary power km/hi) lines and most primary power lines downed.Small buildings overturned or blown away. 5.2 Significant Historical Events Little was recorded of hurricanes striking Hawaii before the last half of the 20th century. Since 1950, when adequate records began, eight hurricanes have affected the Hawaiian 5-6 Hawaii County Multi-Hazard Mitigation Plan