With the severe weather season underway, now is a good time to go over the difference between tornado, severe thunderstorm watches and warnings, advisories and outlook. What does each one mean? Your questions are answered below.
What is a Watch?
A WATCH means that the potential exists for the development of severe thunderstorms or tornadoes, depending upon the specific type of watch issued. In the case of a tornado watch, this DOES NOT mean that a tornado has been seen or even indicated on radar…it just means that conditions are favorable for the formation of tornadoes in thunderstorms. Similarly, a severe thunderstorm watch means that conditions are just favorable for the development of severe weather, and DOES NOT indicate that severe weather has been reported. While no immediate action on the part of the general public is required for the issuance of a watch, citizens should keep up to date on the current weather situation and be prepared to seek shelter if necessary.
What is a warning?
A severe thunderstorm warning, indicates that severe weather is imminent in your area or is already occurring (based on either human observation or doppler radar). The term severe refers to hail greater than or equal to 1.00″ in diameter and/or wind gusts that meet or exceed 58 mph. Although these storms can also be associated with dangerous cloud to ground lightning or heavy rainfall that is capable of causing flash flooding, neither of these two items serve as criteria for a severe thunderstorm warning being issued. A tornado warning can be thought of as a very specific severe thunderstorm warning, and means that a tornado has been either spotted by a human observer or indicated by doppler radar. Similar to a severe thunderstorm warning, once a tornado warning is issued for your area, you should take cover immediately…as the likelihood of you being directly impacted by a tornado is at a heightened risk. With this knowledge of watches and warnings, you will be better prepared the next time severe weather threatens your area.
What is an advisory?
An advisory is issued when a hazardous weather or hydrological event is occurring, imminent or likely. Advisories are for less serious conditions than warnings, that cause significant inconvenience and if caution is not exercised, could lead to situations that may threaten life or property. Just as with an advisory, an outlook is issued when a hazardous weather or hydrological event is possible in the next week. Outlooks are intended to raise awareness of the potential for significant weather that could lead to situations that may threaten life or property.