By the time severe weather hits, it's already too late. Disaster preparedness is about having an established safety plan. Whether it's preparedness for floods, earthquakes, hurricanes, or fires, the key to survival in disasters is planning. Use our preparedness section to stay informed, make a plan, and most importantly—remain safe in an emergency.
Hurricane and Typhoon Lingo
When a tropical weather center (like the National Hurricane Center or the Joint Typhoon Warning Center) are interested in collecting special datasets for an area of disturbed weather, they call it an "invest," because they are investigating the system for potential development. The designation of "invest" doesn't correspond to any likelihood of development, but it does mean there's an area of disturbed weather, and the organizations are looking into it.
A generic term for warm-core weather systems that occur in the tropics, like tropical storms, hurricanes, and typhoons.
A tropical cyclone in which the maximum sustained surface wind speed is less than 39 mph (34 knot).
A tropical cyclone in which the maximum sustained surface wind speed ranges from 39 mph (34 knots) to 73 mph (63 knots).
A tropical cyclone in which the maximum sustained surface wind is 74 mph (64 knots) or more.
A hurricane with winds greater than 110 mph (category 3 or higher on the Saffir Simpson hurricane wind scale).
A tropical cyclone that forms in the Pacific Ocean between 180° and 100°E. Typhoons are similar to hurricanes, and require winds 74 mph (64 knots) or greater.
A tropical cyclone in the Northwestern Pacific with winds of 114 mph (130 kt) or greater (category 4 or greater on the Saffir Simpson hurricane wind scale) is designated a "Super Typhoon."
An abnormal rise in sea level accompanying a hurricane or other intense storm, and whose height is the difference between the observed level of the sea surface and the level that would have occurred in the absence of the cyclone. Storm surge is usually estimated by subtracting the normal or astronomic high tide from the observed storm tide. Storm surge can reach heights well over 20 feet and can span hundreds of miles of coastline.
Watches, Warnings, and Advisories
An announcement that hurricane conditions (sustained winds of 74 mph or higher) are expected somewhere within the specified area. Because hurricane preparedness activities become difficult once winds reach tropical storm force, the hurricane warning is issued 36 hours in advance of the anticipated onset of tropical-storm-force winds.
An announcement that hurricane conditions (sustained winds of 74 mph or higher) are possible within the specified area. Because hurricane preparedness activities become difficult once winds reach tropical storm force, the hurricane watch is issued 48 hours in advance of the anticipated onset of tropical-storm-force winds.
Tropical Storm Warning
An announcement that tropical storm conditions (sustained winds of 39 to 73 mph) are expected somewhere within the specified area within 36 hours.
Tropical Storm Watch
An announcement that tropical storm conditions (sustained winds of 39 to 73 mph) are possible within the specified area within 48 hours.
Short Term Watches and Warnings
These watches/warnings provide detailed information about specific hurricane threats, such as flash floods and tornadoes.
What Do the Categories Mean?
Saffir Simpson Hurricane Wind Scale
|Category||Wind Speed||Expected Damage|
|74 - 95 mph64 - 82 knots||Very dangerous winds will produce some damage- Minor damage to exterior of homes- Toppled tree branches, uprooting of smaller trees- Extensive damage to power lines, power outages|
|2||96 - 110 mph83 - 95 knots||Extremely dangerous winds will cause extensive damage- Major damage to exterior of homes- Uprooting of small trees and many roads blocked- Guaranteed power outages for long periods of time—days to weeks|
|3||111 - 129 mph96 - 113 knots||Devastating damage will occur- Extensive damage to exterior of homes- Many trees uprooted and many roads blocked- Extremely limited availability of water and electricity|
|4||130 - 156 mph114 - 135 knots||Catastrophic damage will occur- Loss of roof structure and/or some exterior walls- Most trees uprooted and most power lines down- Isolated residential due to debris pile up- Power outages lasting for weeks to months|
|5||Greater than 156 mphGreater than 135 knots||Catastrophic damage will occur- A high percentage of homes will be destroyed- Fallen trees and power lines isolate residential areas- Power outages lasting for weeks to months- Most areas will be uninhabitable|
Prepare For the Extreme
Get Severe Weather Alerts
- Tornado Preparedness
- Tornado FAQ
- Where Tornadoes Occur
- Understand the Fujita Scale
- Severe Storms and Supercells
- Flash Floods
- Radar FAQ
- Severe Storms Lingo
Hurricanes and Typhoons
- Hurricane and Typhoon Preparedness
- Storm Surge Basics
- Storm Surge Survival Myths
- Storm Surge: Know Your Elevation
- Inland Flooding and Flash Flooding
- Radar FAQ
- Hurricane Lingo