Don't leave us hanging...
Cat 5 damage is just that. Andrew was a 5 on Florida impact and decimated certain areas, like a bomb. Irma is predicted as a 4 at landfall. Its winds will be more spread out and slower (hopefully) with a smaller eye wall that will do less damage locally at the center impact zones. Irma does have the potential for more widespread damage, but hopefully less catastrophic damage.
Think of damage levels in categories, it is how SS works:
1 74-95 mph
64-82 kt
119-153 km/h Very dangerous winds will produce some damage: Well-constructed frame homes could have damage to roof, shingles, vinyl siding and gutters. Large branches of trees will snap and shallowly rooted trees may be toppled. Extensive damage to power lines and poles likely will result in power outages that could last a few to several days.
2 96-110 mph
83-95 kt
154-177 km/h Extremely dangerous winds will cause extensive damage: Well-constructed frame homes could sustain major roof and siding damage. Many shallowly rooted trees will be snapped or uprooted and block numerous roads. Near-total power loss is expected with outages that could last from several days to weeks.
3
(major) 111-129 mph
96-112 kt
178-208 km/h Devastating damage will occur: Well-built framed homes may incur major damage or removal of roof decking and gable ends. Many trees will be snapped or uprooted, blocking numerous roads. Electricity and water will be unavailable for several days to weeks after the storm passes.
4
(major) 130-156 mph
113-136 kt
209-251 km/h Catastrophic damage will occur: Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months.
5
(major) 157 mph or higher
137 kt or higher
252 km/h or higher Catastrophic damage will occur: A high percentage of framed homes will be destroyed, with total roof failure and wall collapse. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months. Most of the area will be uninhabitable for weeks or months.
EDIT: certainly not trying to downplay the incoming catastrophe, but the damage incurred is not linearly correlated to the size, as seen by Katrina and Harvey and others
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