SWAW Day 2 Severe Weather Watches and Warnings and How to Receive Severe Weather Information

Once again, it's Severe Weather Awareness Week here in Minnesota and Wisconsin, brought to you by the National Weather Service along with the Divisions of Homeland Security and Emergency Management. Each day a new topic of severe weather will once again be covered:

Monday: Thunderstorms, Hail, Wind and Lightning
Tuesday: Severe Weather Watches and Warnings, and How to Receive Severe Weather Information
Wednesday: Flash Floods
Thursday: Tornadoes (Including Two Tornado Drills)
Friday: Heat Waves

We will bring you this information every day from the National Weather Service, including a special post on Wednesday outlining procedures for Thursdays Tornado Drills. Today's subject is Severe Weather Watches and Warnings, and How to Receive Severe Weather Information. We hope you find this information informative and helpful as we enter severe weather season and remember to stick with this blog for the very latest on severe weather throughout the season.

More information on dissemination services from the NWS

Watches...
Are issued when conditions are favorable for tornadoes, severe thunderstorms or flash floods. If you are in a watch area, continue with normal activities but also make plans to seek shelter if necessary.

Warnings...
Are issued when severe weather has been reported or is imminent. Seek shelter immediately if you are in or near the path of the storm. Warnings are issued by county and city names. Make sure you know the name of the county in which you live and the cities that surround you.

Advance Information...
The forecast and warning process begins one or more days ahead of time, when the threat area is determined. Hazardous weather outlooks are issued early every morning, and updated as conditions warrant.

If a Watch is Issued...
Local weather offices are staffed with extra personnel. State officials are notified and they pass the information to the county and local level. Counties and cities activate their spotter groups as the threat increases. TV and radio stations pass the word to the public.

If a Warning is Issued...
Warnings are disseminated swiftly in a multitude of ways, including TV, radio, and over the internet. Advances in technology have allowed people to receive warnings via cell phone, pager, and numerous other methods. Spotters provide important reports on the storm, and emergency officials carry out the plans that the emergency managers have developed. Updates are issued frequently until the immediate threat has ended.

Sirens...
Counties and cities own the sirens and therefore decide how and when to activate them.  The National Weather Service does not sound them. There are many different policies by counties and cities. Some will activate them across the entire county for a tornado warning only. Others will activate sirens countywide for tornado warnings and all severe thunderstorm warnings. Some will activate sirens across the entire county for tornado warnings and severe thunderstorms that have winds of at least 70 or 75 mph.  Others will activate sirens only for portions of counties. Also, local officials may sound the sirens anytime they believe severe weather is a threat, even if there is no warning from the National Weather Service.
Sirens normally sound about 3 minutes and then go silent. It is very rare to keep the sirens sounding for the entire warning, since that will cause the backup battery to run out, which would be critical in the event power goes out. Furthermore, the siren motor will fail much more quickly if the siren sounds continuously. Some jurisdictions may repeat siren activation every few minutes.  There is no such thing as an "All Clear" for storms.

Media...
Media outlets receive the warning information and disseminate it to you, often by interrupting programming. Many television stations use a crawl and other visual means.

NOAA Weather Radio...
The tone alert feature of NOAA Weather Radio will activate specially built receivers, sounding an alarm to alert you to the danger.  It sounds its alert anytime the National Weather Service issues a warning, even in the middle of the night. Make sure you have a NOAA Weather Radio, as you can not always depend on sirens, phone calls or seeing the warnings on television.