Warnings based on Rotating Storms vs. Actual Tornado Touchdown

[Mike Smith]

Those of you who have read Warnings know that it makes the case that meteorologists can now, with high accuracy, specifically warn of the path of major tornadoes. Yet, it appears that many emergency managers still believe it is 1963 -- they sound sirens over entire counties or, in some cases, over multiple whole counties! Given the significant anecdotal evidence that the sirens were (at least at first) largely ignored in Joplin, this has come a big issue: http://meteorologicalmusings.blogspot.com/2011/05/selective-siren-activation-part-3.html

I was in St. Louis Wednesday then sirens were activated over the entire county even though a only small part of the county was threatened each time. KMOV TV interviewed me and the emergency manager: [video]http://www.kmov.com/news/local/Could-a-mass-sounding-of-tornado-sirens-do-more-harm-than-good-122759099.html[/video]. The EM says, "you never know what path a tornado is going to take." Similar comments were made earlier this week by the EM of Johnson Co., Kansas.

Question to the several stormtrack members who are EM's: Is the concept of storm-based warnings still foreign to the EM community? If so, what do we do to change that?

Mike

 

[John Keeton]

In St louis co mo they take an interesting approach to sirens they sound them if an adjacent co has a warning or if stl co is warned. Problem w slow moving storms is the sirens go off for a long time and people ignore them. Too many false positives.

Also the system here is set up for outdoor notification only. They expect people to have a NOAA radio or be watching tv to get notification.

Where I live, just south of stl the terrain doesn't allow for cost effective sirens. So areas have reverse 911 but you have to sign up for it.

If there was more general public communication of the free options and the cell carriers allowed these alerts to be sent via txt for free there might be more adoption and better public awareness.

Apathy is a problem and always will be. We need to eliminate the false positives. Have sirens/alerts use polygons etc.

John

 

[f.vanalstine]

I just wish broadcasters would come to the point quicker when a tornado warning is issued. The warning should be done as follows I suggest:

Tornado at (give local landmarks) moving (give direction) at (give speed). Repeat this at least twice, THEN fill in with all the mundane details. Right now a tornado could move half a mile closer to you in the time it takes for the broadcast to get around to telling you where it really is and where it is going.

Franvan

 

[rdale]

Question to the several stormtrack members who are EM's: Is the concept of storm-based warnings still foreign to the EM community? If so, what do we do to change that?

I've done my best to educate my local community and most that I know personally are onboard with polygon alerts. However many of their siren systems are not compatible with polygons, so while the message might go out in some form - the sirens don't follow.

Tornado at (give local landmarks) moving (give direction) at (give speed). Repeat this at least twice, THEN fill in with all the mundane details.

When you can see the tornado thanks to a chaser stream or webcam, then they do it. But 95% of the time the exact location is not known (let alone if a tornado exists.) What you are expecting is simply not possible.

 

[Chris Novy]

Those of you who have read Warnings know that it makes the case that meteorologists can now, with high accuracy, specifically warn of the path of major tornadoes. Yet, it appears that many emergency managers still believe it is 1963 -- they sound sirens over entire counties or, in some cases, over multiple whole counties! Given the significant anecdotal evidence that the sirens were (at least at first) largely ignored in Joplin, this has come a big issue...

This is complicated issue involving many factors:

1) Are we giving people enough time to react?

2) Are we giving too much lead time -reducing the urgency of the warning?

3) Is it worth risking lives when we know storms can change direction?

4) Do warnings actually change the outcome on an individual level? In other words, does simply knowing about a tornado actually result in people taking extraordinary action to protect themselves?

Part of the St. Louis County siren policy --sounding 200+ sirens for tornado warnings issued for adjacent counties-- was a knee-jerk reaction to a surprise tornado that struck Florissant, MO several years ago. As long as you have politicians, not scientists, making warning policy there will always be the tendency to cover one's ass --or to put it in politically correct terms "err on the side of safety".

That said, there does remain uncertainty as to the absolute track a storm will take and given the potential for mass casualties in a large metro area the threshold for triggering local warning systems may need be lower than is meteorologically warranted. This is the "but, what if..." philosophy.

Clearly polygon (storm-based) warnings provide a much better fit than county-based warnings. While using software to allow triggering of all or just certain sirens based on known conditions is not technically difficult it is politically challenging. Who sets the threshold? How close is too close? These are difficult questions.

Now that said, I do have a problem with cities (and Oklahoma City is one of them) that activate their sirens simply out of panic or because neighboring communities are activating theirs. Last Tuesday we had a major tornado outbreak here. While the storms were still well west of the metro Oklahoma City was sounding the sirens --with clear skies. Now one might argue that this early activation saved lives by giving people 45 minutes to an hour "lead time" since the metro was eventually placed under a tornado warning. Others, however, would argue that despite the carnage going on out west the Oklahoma City metro are was in no imminent danger. Activating the sirens may have only confused residents who were expecting to see a storm in the next few minutes and may have reduced the effectiveness of the sirens when they were later sounded for warnings specifically affecting the metro.

In an ideal world sirens should only be sounded when there's actually a tornado (either visually or highly evident on radar). In reality though there is a lot of uncertainty. Only though sane policies can we make decisions which account for the uncertainty while taking into account the multitude of reasons people choose NOT to take shelter. After all, warnings don't save lives, only actions save lives.

..Chris..