Australian

Catagory              Windspeeds        Descriptions

Cyclone Yasi is expected to cross the north Queensland coast between Cairns and Cardwell at 10pm (AEST) on Wednesday night, coinciding with the high tide. There  are typhoons and storms  that are put into categories due to the severity and damage they can cause.Below are a few  descriptions of the few categories

Cat 1

Winds of 74-95 mph

Damage primarily to shrubbery, trees, and unanchored mobile homes. No real damage to other structures. Some damage to poorly-constructed signs. Low-lying coastal roads inundated, minor pier damage, some small craft anchored in unprotected areas torn from moorings.

Cat 2

Winds of 96-110 mph

Considerable damage to shrubbery and tree foliage; some trees blown down. Major damage to exposed mobile homes. Extensive damage to poorly constructed signs; some damage to roofing materials of buildings; and some window and door damage. No major damage to buildings. Coastal roads and low-lying escape routes inland cut by rising water two to four hours before arrival of the hurricane’s center. Considerable damage to piers. Marinas flooded and small craft anchored in unprotected areas torn from moorings.

Cat 3

Winds of 111-130 mph

Foliage torn from trees; large trees blown down. Practically all poorly-constructed signs blown down; some damage to roofing materials of buildings; some window and door damage; and some structural damage to small buildings. Mobile homes destroyed. Serious flooding at coast and many smaller structures near coast destroyed; low-lying escape routes inland cut by rising water three – five hours before the hurricane’s center arrives.

Cat 4

Winds of 131-155 mph

Shrubs and trees blown down; all signs down. Extensive damage to roofing materials, windows and doors; complete failure of roofs on many small residences; complete destruction of mobile homes. Major damage to lower floors of structures near shore due to flooding and battering by waves and floating debris.

Cat 5

Winds of 155+ mph

Shrubs and trees blown down; considerable damage to roofs of buildings; all signs down; very severe and extensive damage to windows and doors; complete failure of roofs on many residences and industrial buildings; extensive shattering of glass in windows and doors; some complete building failures; small buildings overturned or blown away and complete destruction of mobile homes. Low-lying escape routes inland cut by rising water three to five hours before the hurricane’s center arrives. ( ref : http://www.angelfire.com/fl4/eastcoasttropicalwea/saffirsimpsonscale.htm)