Definition of a Waterspout
There are two types of waterspouts. A fair-weather waterspout develops in the absence of thunderstorms. It can be found at the leading edge of a formation of cumulus clouds. These waterspouts develop first on the surface of the water and move upward as they grow. Most fair-weather waterspouts dissipate quickly after reaching land. They are not associated with strong wind, so they tend to stay in a small area. A waterspout tornado develops from a thunderstorm. It can start on land or on water. This type of tornado can move a considerable distance. A waterspout tornado is from the same type of weather formation as a tornado that spends all of its time on land.
How a Waterspout Tornado Forms
A waterspout tornado forms from a thunderstorm. They are associated with severe thunderstorms and supercell thunderstorms. The storms often include heavy rain, high wind, hail, and lightning. A waterspout tornado begins at the cloud level and moves downward toward the water. If it developed on land, it may continue across the water before dissipating. They can cross small bodies of water such as a creek as well as large rivers and lakes.
Why a Waterspout Tornado Can Be Dangerous
A waterspout tornado can have strong winds and rotation. When a person is on or near water, there is a risk of drowning if caught in a waterspout tornado. The high winds could blow a person into the water if the person is on a dock, pier or boat. Lightning strikes from the storm also present a hazard. When a waterspout tornado sucks up water and is surrounded by rain, it can be difficult to see. If one of these storms occurs at night, the situation is particularly dangerous due to the limited visibility. These storms can also capsize boats.
Weather Alerts for Waterspout Tornadoes
According to the National Weather Service, a tornado warning will be issued for a tornado that is sighted or indicated by radar over a body of water. Waterspout tornadoes that develop from a severe thunderstorm should be visible on weather radar. Modern radar technology allows meteorologists and emergency management officials to recognize the rotation. During the twilight and nighttime hours, this is especially important. Boaters, weather spotters and swimmers would not be able to visualize a waterspout tornado in dim or dark lighting conditions or in a heavy rainstorm. Tornado warnings are issued for these storms. A tornado warning for maritime interests may also be issued for a fair-weather waterspout.
Emergency management professionals need to know about all of the potential threats to the people in their jurisdiction. This includes the possibility of severe weather. Knowing what a waterspout tornado is will make it easier for emergency management authorities to take action and work in conjunction with the weather service in order to issue alerts to the public.