Flood Watch: High flow or overflow of water from a river is possible in the given time period. It can also apply to heavy runoff or drainage of water into low-lying areas. These watches are generally issued for flooding that is expected to occur at least 6 hours after heavy rains have ended.
Flood Warning: Flooding conditions are actually occurring or are imminent in the warning area.
Flash Flood Watch: Flash flooding is possible in or close to the watch area. Flash Flood Watches are generally issued for flooding that is expected to occur within 6 hours after heavy rains have ended.
Flash Flood Warning: Flash flooding is actually occurring or imminent in the warning area. It can be issued as a result of torrential rains, a dam failure, or ice jam.
Hurricane Watch: Hurricane conditions (sustained winds greater than 73 mph) are possible in a certain area of the watch, usually within 36 hours. You should stay tuned for additional advisories.
Hurricane Warning: Hurricane conditions are expected in a certain area of the warning, usually within 24 hours. You should do what you can to prepare for the storm and evacuate if asked to do so by local authorities.
Severe Thunderstorm Watch: Conditions are present for severe thunderstorms in and close to the watch area.
Severe Thunderstorm Warning: A severe thunderstorm has actually been seen by spotters or indicated on radar, and is happening or close in the warning area.
Tornado Watch: Conditions are present for tornadoes in and close to the watch area.
Tornado Warning: A tornado has actually been seen by spotters or indicated on radar and is happening or close in the warning area.
Tropical Storm Watch: Tropical storm conditions with sustained winds from 39 to 73 mph are possible in the watch area within the next 36 hours.
Tropical Storm Warning: Tropical storm conditions are expected in the warning area within the next 24 hours.