The Saffir-Simpson Hurricane Scale is a 1-5 rating based on the hurricane’s present intensity. This is used to give an estimate of the potential property damage and flooding expected along the coast from a hurricane landfall.
Wind speed is the determining factor in the scale, as storm surge values are highly dependent on the slope of the continental shelf and the shape of the coastline in the landfall region. These speeds are one minute averages and not maximum gusts!
| Category | Wind Speed (mph) | Wind Speed (kmph) | Storm Surge (feet) |
|---|---|---|---|
| 1 | 74-95 | 119-153 | 4-5 |
| 2 | 96-110 | 154-177 | 6-8 |
| 3 | 111-129 | 178-208 | 9-12 |
| 4 | 130-156 | 209-251 | 13-18 |
| 5 | >157 | >252 | >18 |
When a hurricane or tropical storm is near and a threat has been determined, the Cayman Islands Hazard Management Department (HMCI) and Government will issue press releases, and there will be four various hurricane flags hung outside of police stations and government buildings.
Listed below are the relevant flags, along with descriptions of what each flag means. Keep in mind that, even if the All Clear (green) flag is being flown, there is still a possibility for damage to occur due to a storm surge. Please use caution if you see any of these flags, or have been told that a hurricane threat has been issued.
Knowing the difference between hurricane signal flags and tropical storm signal flags is also important. Hurricane flags are square while tropical storm flags are triangular.
Hurricane Signal Flags
Hurricane Alert
Hurricane threat more than 36 hours away.
Flag Description: One square red flag.
Hurricane Watch
Hurricane threat 24 to 36 hours away.
Flag Description: One square red flag with a black square in the centre.
Hurricane Warning
Hurricane conditions expected within 24 hours.
Flag Description: Two square red flags with a black square in the centre.
All Clear
The hurricane has passed, but still use caution.
Flag Description: One square green flag.
Tropical Storm Signal Flags
Tropical Storm Alert
Storm threat more than 36 hours away.
Flag Description: One triangular red flag.
Tropical Storm Watch
Storm threat 24 to 36 hours away.
Flag Description: One triangular red flag with a black square in the centre.
Tropical Storm Warning
Storm conditions expected within 24 hours.
Flag Description: Two triangular red flags with black square in the centre.
All Clear
The storm has passed, but still use caution.
Flag Description: One triangular green flag.