Obviously, that will vary a great deal, depending on the local policies for sounding the alarms.
I live in Cook County, which is fairly large. My municipality (in the central part of the county) doesn’t usually sound the tornado sirens when the tornado warning is for the extreme southern or northern parts of the county, unless the storms in question are forecast to head into our area. So, our “false alarm” rate, from the standpoint of the tornado sirens, isn’t that high.
However, the warning tones on the television (through Comcast) go off whenever there’s a tornado warning for anywhere in Cook County.
In the end, I think that most governments are going to err on the side of safety – that is, they’d rather give a warning which turns out to not be needed, rather than not issue a warning when it was needed. Unfortunately, it can lead to complacency, and the “boy who cried wolf” phenomenon. (I know that the same thing happens with tsunami warnings in the Pacific Basin, though the two devastating tsunamis in the past few years may have changed that, a bit.)
Speaking as a meteorologist, NWS warnings are now polygons (and have been for a few years), they do not officially include entire counties. Many TV stations (and possibly emergency management) still go by the “county” and disseminate warnings that way, for whatever reason. Ideally, sirens would only sound for tornado warnings, for locations actually in the polygon, which has it’s own “buffer.”
Unfortunately, the sirens are not controlled by the NWS, they are controlled by the local government/fire/police or emergency management, and the requirements to blow the sirens can vary drastically from place to place (as we can see in this thread).
As for the reason for the large death toll in Joplin, we are still at the guessing phase. Some possibilities (in no particular order of importance):
Though there was about 20 minutes of warning (the tornado warning came out at 5:17pm, with a spotter report of a tornado just outside Joplin no later than 5:37pm), the tornado strengthened extremely rapidly just as it reached the city. Some of the radar scans I saw had relatively weak velocity couplets (though still worthy of a tornadic circulation) until it reached just west of the city, which increased to extremely strong over the course of a few minutes, with no doubt there was likely a strong tornado on the ground, or about to form at anytime.
Joplin seems to be a “regional” weekend gathering place, with plenty of people from around the area, who may not be intimately familiar with the local geography/safe places. Similarly, more people than normal may be out and about, compared to the “normal” workday during the MS/TN/AL/GA outbreak a couple weeks ago.
There was a high school graduation yesterday. While the graduation was held not in the city, there may have been many parties going on (which swings back to point #2 regarding unfamiliarity).
Apparently, the area hit was very heavy residential, non-subdivision, with relatively closely packed housing.
As has been mentioned above, this was a very strong tornado. If you were not underground, it may have been impossible to avoid serious injuries in some instances.
Other factors aside, with time being extremely important, wouldn’t it make sense to put the button for the sirens under the finger of the person detecting the tornado, ie. the NWS? All the tornado sirens in my county are owed by the cities. I wonder who has the authority to sound them. Does it vary by city or does the county emergency management head do it? With tornadoes being 24/7 and heavy on evenings, would we lose time finding somebody?
Well, first of all, while they’re used almost exclusively as storm sirens now, I believe that their original use was as civil defense sirens (i.e., air raids, etc.).
As such, they’re likely under the control of local emergency-management agencies. I’d be highly surprised if, with the exception of the very smallest communities, the fact that a storm happens on a weekend evening (or 3 a.m.) shouldn’t have any impact on how quickly the alarm is sounded.
My county is around 600 square miles. A couple of years ago there was a warning for the smallest sliver of the Northeast part of the county. It had to have been only 10 square miles of the county under warning out of more than 600. There are no sirens in that very sparsely-populated area. Every single siren in the county was sounded anyways.
One county’s (it may have been mine, I don’t remember) EMA director said that they do that as a public service, because “tornadoes are unpredictable.” :rolleyes: (Not that unpredictable. The storm would have had to have made a 140 degree turn and continued going that direction for almost 40 miles to hit the farthest siren that was activated.)
The Time Warner branch in my area doesn’t put EAS alerts out on HD channels. But it does shut those channels off in a feeble attempt to make the boxes display the warning. So if you were watching storm information on one of the broadcast networks, you lose it for the duration of the alert you can’t see or hear.
Well, yes, the NWS is on duty 24/7. But, even in the smallest community, there’s going to be some sort of first-responder on duty, even if it’s a county sheriff’s deputy who’s some distance away. It’s no different from what’d happen if there were a car accident in the middle of the night.
If I heard any siren (highly unlikely in my remote area), I would be the first outdoors with my video camera. I might die in the funnel, but what YouTube coverage I would get!
True. Last week we had a storm with large hail. Several people caught outside wound up in the hospital, one of them being completely knocked out and the two who dragged him to safety getting injured themselves. No tornado, “just” a thunderstorm.
If I am outside and a storm is coming, I can easily tell it is coming. The wind, black clouds, strange colored sky, moisture in the air… I may not have any idea how severe it will be, or if there is a chance of a tornado, but I know enough to come in out of the rain. I may stay out until the last minute trying to finish something up or taking things in, but when the storm hits, I am going inside. Once inside, I have few options, living in common frame house built on a crawlspace. I fail to see changing my behavior due to sirens.
I am surprised at the apparent regional variations in how sirens are handled. I’m in central Ohio, and as Gedd mentioned, the sirens only go off here when there is an actual tornado warning. This is not just a “Gee, you should probably come inside” warning - this is a “go to your basement or other protected spot” warning.
When I hear sirens, I get my ass to the basement ASAP. Yes, it’s annoying when they go off a lot during tornado season and we don’t actually get a tornado, but I’d rather be annoyed by hanging out needlessly in my basement a few times, than have my house fall on top of me without warning.
Severe storm systems can be extremely fast-moving. I can think of a couple times from when I was younger where a bunch of us were outside, and by the time we heard any thunder the storm was less than a couple of minutes away.
Viscera’s comment about graduation parties and people unfamiliar with the area makes sense and might explain some of the deaths. And it’s worrisome. Our town has a community picnic in the park every year, and our community hall (with no basement) is often rented for big parties. There’s no place for those people to go in the event of a tornado.
We’re finally getting a tornado siren. It’s being set up so that it can be activated by EMS personnel in the closest town and also by buttons on the walkie-talkies that the local spotters and volunteer firemen have.
Sirens go off locally now if the wind reaches 70mph. It confuses the simple people of my town every time they go off. “Is it a tornado?” “Is it high winds?” “Is WW3?”
The last time this occurred, the 911 system was overwhelmed with callers wondering why the sirens went off.
