Severe weather awareness week

We’ve already seen our first tornadoes of the year in Minnesota, on March 6.

The 3 tornadoes that day set a new record for the earliest tornadoes ever observed in Minnesota.

Thankfully, the March 6 tornadoes didn’t cause any fatalities.

Severe weather awareness week

As we move into the warmer days of spring, we see more frequent thunderstorms.

Tornadic supercell thunderstorm illustration, via NOAA

We need to be ready when thunderstorms become severe, so Minnesota and Wisconsin have declared April 17-21, 2017 Severe Weather Awareness Week.

According to the National Weather Service:

Information about various topics on severe weather safety will be presented each day by the NWS Twin Cities. The list of daily topics for Severe Weather Awareness Week is:

Monday, April 17th – Weather Alerts and Warnings

Tuesday, April 18th – Severe Storms, Lightning, Wind and Hail

Wednesday, April 19th – Flash Floods

Thursday, April 20th – Tornado Safety Information

Friday, April 21st – Extreme Heat

As part of Severe Weather Awareness Week, tornado watch/warning drills will be held on Thursday, April 20th.

Watch vs. warning

There is sometimes a bit of confusion about the difference between a severe weather watch and a severe weather warning.

Maybe the fact that “watch” and “warning” both begin with the letter “w” makes it harder to differentiate between the two.

Here are some details on severe weather watches and warnings, from the NWS:

Severe Weather Watches and Warnings, and How to Receive Severe Weather Information

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.

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.

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 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.

Severe weather spotter training

The NWS and local law enforcement officials can always use “ground truth” information about severe weather that is occurring.

You can get free training to become a severe weather spotter:

We’ll post additional information about Severe Weather Awareness Week topics in the coming days.

And of course, Minnesota Public Radio is a static-free source of severe weather information throughout the year.