Activate sirens for SVR warning?

[Kevin Crawmer]

I agree with the sirens being set off at 75+ or some criteria like that. There have been several instances where lives could be saved if that happened.

As far as the "false alarms" shouldn't the polygon warnings help decrease those by quite a bit? I think there will be a lot fewer instances where the sirens are going off, but nothing happens now. At least with the polygon warning system if you get a warning you're gonna get something exciting.

That is of course the EMs sound only if they are within the polygon.

 

[Patrick McCarthy]

I've always advocated a clear, tiered warning system that would be issued by a central authority. I've also advocated that all warning agencies use the same tiered terminology so that the public can more readily understand the messages. Can Joe six-pack appreciate the subtleties between "Watch", "Warning", "advisory", "Alert", "special statement", "threat level", etc.? There is a North American effort to agree to an internationally designed "common alerting protocol". It's more for the dissemination mechanics but you could imagine designing it with a common tiered verbology.

I also agree that users can choose to respond as they see fit, as long as that is clearly communicated to their users.

Up here in Canada, the Alberta government runs their Emergency Public Warning System (just Google it). It's used for emergencies like Amber Alerts, "Boil water" advisories, flash flooding, etc. But it was originally designed in the aftermath of the 1987 Edmonton tornado. Canada's weather service activates the system most of the time. The activation interupts all TV/radio broadcasts in targeted area. The person activating records an emergency message which gets broadcast during the interuption. It's an amazingly effective system. The Alberta government has chosen its own weather warning guidelines for activation. All weather service tornado warnings are activated, as are "dangerous Supercells" (for want of a better term). Essentially the latter are supercells affecting a highly populated area where the risk of injury/destruction is higher, though the forecaster has discretion in whether activating in the end. The Alberta government is comfortable with the weather service's own dissemination system for supercells tracking through less populated areas.

Pat

 

[rdale]

As far as the "false alarms" shouldn't the polygon warnings help decrease those by quite a bit?

Yes, but many sirens are sounded by 911 centers instead of a specific person sitting in the EM office. The good is that there's always someone around. The bad is that they don't get the polygon, all they get is the alert that their county is under a warning. So even if they do have the ability to only sound certain sirens, it doesn't matter since they blanket them all.

I'm working on software that will plot the warning on Google Earth backgrounds, zoomed in tight, and will use a preset list of siren locations to send "SOUND THE SIRENS IN ..." "DON'T SOUND THE SIRENS IN ..." as a text message for cellphones and email to whoever based solely on the polygon.

 

[Tim Shriver]

I agree with sirens being sounded for SVRs with winds above 75 mph. This would make sense. There is software out there that will sound automatically and use polygons
already. So the EOC or EM would not have to be staffed to do this. It is based
on the Weather Message software. For the life of me I cannot remember the persons name but he started work on it over a year ago
and has deployed it to some degree.

Having it automated is important to smaller counties. In our area some counties have automated
warning systems. If a TOR comes through and their county is in it, the system triggers the
sirens. I know of three counties in Southern WI that have this, but they trigger the whole county
at this time.
Others like RDale said depend on the 911 center.

We are lucky here in Dane that the EOC is staffed and they use a new
system that allows them to trigger siren zones within the county. They are
manned 24/7. But even then, a few towns are not on this system.
So they are on their own and often do a poor job of it.

But when the winds are howeling sirens are often hard to hear
and even less affective when folks are sleeping at night.
Weather radios, cell phone alert services etc. may be the
better solution in the end.

Beside, I still think of the "tornado sirens" as air raid sirens anyways...

Tim

 

[Darrin Rasberry]

Moved from the 5/1 DISC thread:

At the risk of resurrecting a previous debate, this is in my mind why enhanced wording--i.e. "tornado emergency"--is appropriate and desirable in extreme situations.

I agree with this, but what kind of enhanced wording would be needed for a high-wind event like this one, in which tornadoes are constantly possible but very hard to detect even during the day (due to lack of wall cloud, suddenness of formation, etc.)?

I believe I have an answer that might cause more controversy than the "tornado emergency" term, but just might work.

Here's my case:

1. Bow-echo/derecho events such as this one should be very carefully studied. Specifically, some method to quickly determine tornado potential in an ongoing bow echo event should be researched. I will leave it to the scientists here to judge whether such a method is possible or cost-prohibitive, but I have a hunch it can be done.

2. In that case, should such a bow echo exhibit these theoretically observed features, tornado warnings should be issued along the relevant portions of the storm for the duration of the theoretical conditions.

3. In the case that the conditions are, for some reason, not reliably determined and applied to assess a significant tornado potential, elevated wording coupled with siren warnings and T.V. interruptions by local management should still happen. The following could serve as a definition and starting point for such an event: tornado-caliber alerts should be initiated when a severe weather event poses an unreasonable threat of injury or death to an informed person in shelter, or rationally acting to seek shelter.

This assumes responsibility on a population to know the risk, and to have a back-up plan while they are outside (i.e. park their vehicles and seek shelter, get into a sturdy structure if outdoors, move away from windows and into an interior room, and if in a mobile home, seek a sturdier structure if one has time). Normally, these precautions are enough to warrant not sounding the sirens for SVR-warned storms of the lower calibur that rdale mentioned. Although lighting, flooding, and even windblown and/or large hail may be deadly, they will not be deadly to people taking the responsibility to seek sturdier and more secure shelter, or staying indoors if they are already in there.

Thus, it seems that wind events are the main cause for extra alerts. Obviously the tornadic situation is taken care of. But what about high-wind straight line events, with or without the strong potential for tornadoes? Again, it's more the place of scientists to determine, but when straight-line winds are at or above a certain sustained level (say, 58+ or hurricane-force) or a certain gust level (say 75+) the event should pose an additional risk to those indoors or in a shelter, and those people ought to be alerted, like in a tornado warning, that extra action should be taken to further reduce the risk for injury or death. Thus, sirens should be sounded, etc., and strong wording such as "hurricane-force winds capable of widespread damage to trees and structures" ought to be broadcast.

 

[Stephen Levine]

I believe that anything that has upper end severity should be warned with sirens, be it 75 MPH or greater gusts, hail baseball or larger, or tornadoes.
In general discussions that I've had over time with friends and acquaintences around here, most people associate the sirens with a tornado warning. Yet, during a derecho event last month, a few towns chose to activate the sirens, despite no tornado warning being present, precisely because of the damaging winds already recorded in the storms that were heading their way.
Other towns chose not to activate the sirens.

 

[Chris Sokol]

Why? If straightline 100mph winds are coming in, those can be MORE damaging than an EF0 tornado... So you'd sound them for the 60mph tornado but NOT the 100mph straightline? I guess I don't see what problems there would be.

I have to agree with this 100%. We have all seen just how dangerous and damaging these winds can be, and they pose an even greater danger to the general public, as they are usually not as aware of what these winds can do...and they affect a much broader area than a tornado.

 

[Terry Tyler]

personally, i believe the sirens should be used when theyre needed most...like for example there was a big public event going on in a city, and a severe storm with some large hail, or some very serious winds was coming in...OR!! whether it was severe or not, say it was putting down a serious amount of cloud to ground lightning...people should take cover in a major event, like a football game or concert or something of that nature...like, say they had the taste of colorado event, and there was a storm with no tornado threat, but was throwing down baseball size hail...

a good time to activate sirens and tell people to take cover!

also, a good time to activate the sirens for a SVR storm would be if it was producing signifigant severe weather 2"+ inch hail, or 70+ MPH winds...like, if there was a life threatining situation that wasnt tornadic, then they should activate the sirens anyway that way people werent out in something that was a little bit harder then the run of the mill severe storm...

activating sirens on a marginally severe event wont do anything but decrease peoples concern of the severe threat...hell, if they put the sirens on for 1 inch hail, id laugh my ass off and walk outside and play in it...

bottom line is, atleast in my opinion...the sirens dont need to be activated unless a large population is going to be effected, or if the threat is going to be on a signifigant level to where it could cause damage and the people need to be taking shelter to avoid getting hurt or something...

abuse of the sirens isnt really an issue around here, but apparently is somewhere else...i dont know who is in charge of letting the sirens off, but if they are letting em loose for a marginally severe storm, then hell i say they let em go...

 

[rdale]

whether it was severe or not, say it was putting down a serious amount of cloud to ground lightning...people should take cover in a major event

Ehh, I think Mother Nature has her own alerting system for a storm with an extreme amount of lightning