When severe weather strikes and you hear a meteorologist say “tornado watch” or “tornado warning”, you may be wondering what’s the difference?
Below, we outline the definitions for a tornado watch and tornado warning, along with other terms that are good to know during a severe weather event.
Terminology to Know:
This is issued when conditions are favorable for the development of tornadoes in and close to the watch area. Their size can vary depending on the weather situation. They are usually issued for a duration of 4 to 8 hours. They normally are issued well in advance of the actual occurrence of severe weather. During the watch, people should review tornado safety rules and be prepared to move a place of safety if threatening weather approaches.
If a Tornado Warning is issued for your area, it’s time to take action. This is issued when a tornado is indicated by the WSR-88D radar or sighted by spotters; therefore, people in the affected area should seek safe shelter immediately. They can be issued without a Tornado Watch being already in effect. They are usually issued for a duration of around 30 minutes.
3Flash Flood Watch
A Flash Flood is flooding caused by heavy or excessive rainfall in a short period of time (generally less than 6 hours). A Flash Flood Watch indicates current or developing conditions that are favorable for flash flooding in and close to the watch area, but the occurrence is neither certain or imminent.
4Flash Flood Warning
A Flash Flood Warning means flash flooding is in progress, imminent, or highly likely.
5Severe Thunderstorm Watch
This is issued when conditions are favorable for the development of severe thunderstorms in and close to the watch area. A severe thunderstorm by definition is a thunderstorm that produces one inch hail or larger in diameter and/or winds equal or exceed 58 miles an hour. The size of the watch can vary depending on the weather situation. They are usually issued for a duration of 4 to 8 hours. They are normally issued well in advance of the actual occurrence of severe weather.
6Severe Thunderstorm Warning
A Severe Thunderstorm is a storm that produces a tornado, winds of at least 58 mph (50 knots or ~93 km/h), and/or hail at least 1″ in diameter.
A Severe Thunderstorm Warning is issued when either a severe thunderstorm is indicated by or a spotter reports a thunderstorm producing hail one inch or larger in diameter and/or winds equal or exceed 58 miles an hour; therefore, people in the affected area should seek safe shelter immediately. Severe thunderstorms can produce tornadoes with little or no advance warning. Lightning frequency is not a criteria for issuing a severe thunderstorm warning. They are usually issued for a duration of one hour. They can be issued without a Severe Thunderstorm Watch being already in effect.
A radar pattern sometimes observed in the southwest (right, rear) quadrant of a tornadic thunderstorm. The rain echo forms the hook pattern as air rotates around the strong updraft. The updraft is the hollow portion of the hook (looks like a backwards “J” or a 6) and is where the tornado would most likely be found (if the storm were to produce one). This signature is in the radar reflectivity field; Doppler radar’s velocity information can help confirm the presence of a tornado, especially when a hook echo exists in the reflectivity field.
A funnel-shaped cloud extending from a towering cumulus or thunderstorm.
It is associated with a rotating column of air that has condensed to form a cloud.