Is the tornado pattern REALLY changing? Interactive map of US tornaodes over time.

[dixiegrrrrl]

The visual really is striking.
At the top of the map, you can move a slider for each year, which also is an indication of where the jet stream has pushed the "tornado belt".

http://www.nytimes.com/interactive/2011/04/28/us/tornado-deaths.html?ref=us

[snooper2]

1. looks completely random to me

I'd like to see the data for the last 5000 years and have somebody that know's what they are looking at explain it to me :)

[barbtries]

2. what i learned from that

is that apparently the 4 children killed in Raleigh NC (Wake County) are not counted among the dead from tornadoes. i don't get that.

[dixiegrrrrl]

3. What is noticable is from the year 2000 on, the # of tornadoes has really increased.

If you push the slider back to 2000 and then hit the "play" button, the increase is very visible.

[pintobean]

15. This puts that into perspective

[dixiegrrrrl]

19. I find that a helpful graph. Thanks.

:hi:

[NeedleCast]

28. I would assume a lot of that has to do with increased finding/tracking capabilities

And isn't so much an effect of there actually being a large increase in tordados per yer.

[Xithras]

32. The difference is mostly technology.

Back in the 1950's, a tornado had to be seen by a human being to be counted. If it touched down at night, or in a remote area, it probably wouldn't be counted unless it hit a population center.

Between improving weather radar quality and expanding population (more eyes), fewer and fewer tornadoes escaped detection as the decades wore on.

The big jump around 2000 roughly corresponds to the rollout of fully computerized pulse doppler radar systems that can now identify and log tornado vortexes without ANY human intervention. There wasn't a big jump in the number of tornadoes; technology simply improved enough so that we can now see how many there really are.

[The Straight Story]

4. That looks like deaths and not where tornados were reported

Can't really see any major pattern changes.

[hedgehog]

16. Take a look at states like New York where tornadoes used to b e unheard of.

When I was growing up in Buffalo, we didn't even get many thunderstorms!

[Little Star]

5. Does it seem like the tornado belt keeps moving east? n/t

[madokie]

6. I'd say totally random

Peggs Oklahoma was wiped off the may back in 1920, Pryor Oklahoma was almost wiped off the map in 42
I live smack dab in the middle between the two towns


http://newsok.com/oklahomas-10-deadliest-tornadoes/article/3351036

[bighart]

7. To some degree these things are useful.

The thing is the explosion of technology, both on the detection and reporting side and the massive increase in cell phones and digital recording media, means that many more of these storms are identified and reported now than would have been even 20 years ago. Given that fact the data is skewed somewhat.

[spinbaby]

9. I didn't think of that

That could account for the increase on the map.

[nichomachus]

11. Even without cell phones

I think a lot of people know when they get whacked with a tornado

[Arkansas Granny]

27. Not only is the technology better, until just recently, sightings by the general public

were often not included as they were not deemed to be reliable. Tornadoes were not counted until they were verified by law enforcement or someone considered to be an expert.

[NeedleCast]

29. Exactly. Look at the Number of Amatur and Professional Storm Chasers Now

Do you think people were doing so much of this before the late 90s? Now, with laptop computers and wireless internet storm chasers can use atmospheric data to better predict the strength, location and relative speed/direction storms and super cells are forming in and going to, and they can use cell phones or the internet to report those tornado spawning storms. This is a very recent capability and why we've seen an "increse" in the number of reported torndaos.

[spinbaby]

8. A dramatic increase in the late 90s

If you hit play and watch the number of tornadoes (blue dots) you notice that they really seem to explode in the last part of the 20th century. The number deaths didn't go up as dramatically as the number of tornadoes, so presumably we have better warning systems and shelters.

[Fumesucker]

10. The total number of deaths really seems to jump after 1995

And the distribution seems a bit different too..

[SoCalDem]

18. suburban sprawl

When there was a lot of "open country" it was more likely that tornadoes ripped up cornfields & maybe hit a few scattered farms, but now those cornfields are housing developments & shopping centers..

[Fumesucker]

20. Suburban sprawl took decades..

After 1995 it was like someone flipped a switch and the death count climbed very quickly.

Suburban sprawl might be part of the answer but it's not the whole thing.

[Bosonic]

24. The most logical explanation

is a change in the methodology for tornado reporting at NOAA/NWS, probably allowing internet based reporting (which fits with 1995+). Hence the sharp increase in 'tornado touchdowns and tracks' but *not* a noticable increase in the actual number of reported deaths.

[kickysnana]

12. The tornadoes here almost never miss Fridley as long as I remember n/t

[trotsky]

26. Seems that way.

Fridley, Anoka, Elk River, Hugo - those northern metro areas seem to be affected a lot.

[reggie the dog]

13. this year is really bad for the deep south

and i fear that will move north to the midwest/great lakes region in june as the heat moves farther north...

[laundry_queen]

14. The marked increase in the number of tornadoes is astounding

It really starts to go up near the end. There are some things that could explain some of the increase - more reporting of tornadoes (most places now have trained spotters, and storm chasing is more popular now than when I first heard of it in 1987) but I don't think that would account for all of the additional tornadoes. Another thing that is amazing, is even with the large increase in tornadoes, the number of deaths doesn't make the same jump (except for this year) which is a testament to additional minutes of warning time thanks to science. Great map, thanks.

[dixiegrrrrl]

21. coverage on the local weather channels has been very good, I have noticed.

and most of us who live in storm country know to keep an eye on radar, via computer, or tv weather, when these storm bands move in. It is the FIRST thing we do in the am and last thing we do at night, check the weather.
So the early warnings are getting better.
Altho, the tornado in Oklahoma yesterday afternoon did hit a lot of cars on the inter-state. Dunno if they were listening to weather info.

[kestrel91316]

23. With improved early warning the deaths should be DECREASING.

That the opposite seems to be happening is a bit disconcerting to me.

[NeedleCast]

30. Not an increase in Tornados

An increase in our ability to predict, find and report them.

[sinkingfeeling]

17. Sure is a noticeable increase in the number of them since the mid-90's.

[NeedleCast]

31. Not really, See Post 30.

[Shagbark Hickory]

22. Looks like if you just move out west you're in the clear.

Ah. If only I had 10 million dollars I could buy a shack out west.

[EC]

25. The pattern isn't

the fierceness of them are.