Hoosier Posted March 13, 2011 Share Posted March 13, 2011 As severe season ramps up, I thought it would be useful to post some climo stuff regarding severe thunderstorms. There's multiple ways to look at this - one way is the average annual number of DAYS of severe weather and another is the average annual number of REPORTS. First, the number of days. The following series of maps show the average annual number of days of various types of severe weather from 1980-1999 (within 25 miles of a point). TORNADO WIND HAIL Significant tornado days from 1921-1995 (again within 25 miles of a point) Maps of shorter time periods (1980-1984, 1985-1989 etc) as well as other "significant" severe (75 mph wind or greater, 2" or greater hail) can be found here: http://www.nssl.noaa.gov/hazard/totalthreat.html Now let's forget the number of days and look at the average annual number of severe reports/events. Average Annual number of tornadoes by state, 1953-2004 Average Annual number of tornadoes per 10,000 square miles by state, 1953-2004 another view of tornadoes per 10,000 square miles SPC has gridded data for all severe weather types from 1950-2002. Grid size makes population bias more evident. Example: Significant Severe Killer tornadoes Many more maps here: http://www.spc.noaa.gov/climo/online/grids/ Link to comment Share on other sites More sharing options...
aslkahuna Posted March 13, 2011 Share Posted March 13, 2011 Due to lack of reporting stations, the incidence of severe thunderstorms in southern Arizona is WAY underestimated. Steve Link to comment Share on other sites More sharing options...
Hoosier Posted March 13, 2011 Author Share Posted March 13, 2011 Due to lack of reporting stations, the incidence of severe thunderstorms in southern Arizona is WAY underestimated. Steve Yeah I'm sure underreporting is a big issue out that way and in the Plains (especially western). Link to comment Share on other sites More sharing options...
whitemountainhiker Posted March 13, 2011 Share Posted March 13, 2011 Interesting how the killer tornadoes has two max gridpoints, near Birmingham, AL, and western TN, meanwhile the OKC area has the most significant severe weather reports in the country. Do you think that has to do with less storm cellars in Alabama and Tennessee, or people just don't take the warnings seriously there? Link to comment Share on other sites More sharing options...
SacrydDreamz Posted March 13, 2011 Share Posted March 13, 2011 Interesting how the killer tornadoes has two max gridpoints, near Birmingham, AL, and western TN, meanwhile the OKC area has the most significant severe weather reports in the country. Do you think that has to do with less storm cellars in Alabama and Tennessee, or people just don't take the warnings seriously there? I would suspect the number of deaths in the Deep South is due to a number of factors... one you mentioned and that's adequate shelter. A related factor would be the incidence of prefabricated homes and trailer. Then there is the fact that the Deep South is prone to early and late season severe events, many of which occur at night (and this topic can be expanded on, if you wish). Additionally, the region is much more densely forested, so you can't see a tornado a miles out... hell, you'd be lucky to see it 100 yards away in many areas. Lastly, you're more likely to get high-precipitation supercells in the Deep South versus the Plains. Link to comment Share on other sites More sharing options...
The Dude Posted March 13, 2011 Share Posted March 13, 2011 Average Annual number of tornadoes per 10,000 square miles by state, 1953-2004 Thanks for the maps. Really surprised to see Maryland at #8 in the above map. I would suspect the number of deaths in the Deep South is due to a number of factors... one you mentioned and that's adequate shelter. A related factor would be the incidence of prefabricated homes and trailer. Then there is the fact that the Deep South is prone to early and late season severe events, many of which occur at night (and this topic can be expanded on, if you wish). Additionally, the region is much more densely forested, so you can't see a tornado a miles out... hell, you'd be lucky to see it 100 yards away in many areas. Lastly, you're more likely to get high-precipitation supercells in the Deep South versus the Plains. All great points. In addition, the Deep South has a much greater population density than the plains. Link to comment Share on other sites More sharing options...
Hoosier Posted March 13, 2011 Author Share Posted March 13, 2011 Thanks for the maps. Really surprised to see Maryland at #8 in the above map. All great points. In addition, the Deep South has a much greater population density than the plains. There were a few things that surprised me. I didn't expect to see the relatively low numbers in KY/TN, although the eastern parts of those states bring down the state average. The states that score the highest really don't have much area that goes to waste. Link to comment Share on other sites More sharing options...
Hoosier Posted March 13, 2011 Author Share Posted March 13, 2011 Here's some info about nocturnal tornadoes. I'm not exactly sure what they define as nocturnal for the map but it gives a general idea. http://www.niu.edu/PubAffairs/RELEASES/2008/nov/tornado.shtml Link to comment Share on other sites More sharing options...
whitemountainhiker Posted March 13, 2011 Share Posted March 13, 2011 I would suspect the number of deaths in the Deep South is due to a number of factors... one you mentioned and that's adequate shelter. A related factor would be the incidence of prefabricated homes and trailer. Then there is the fact that the Deep South is prone to early and late season severe events, many of which occur at night (and this topic can be expanded on, if you wish). Additionally, the region is much more densely forested, so you can't see a tornado a miles out... hell, you'd be lucky to see it 100 yards away in many areas. Lastly, you're more likely to get high-precipitation supercells in the Deep South versus the Plains. This reason may be a bit more controversial, but what about education, meaning....actually knowing what a tornado warning means, and taking it seriously. There is only so much the weather service can do. I cannot say for sure that people who live there take the warnings seriously, but sometimes I wonder. And I'm not only talking about people in the south. All you have to do is check out youtube and watch videos of people putting themselves in harms way (the latest tsunami, floods, etc etc). All great points. In addition, the Deep South has a much greater population density than the plains. I never really thought of parts of the south as a highly densely populated area, but compared to the midwest, minus some of the bigger cities, that has to be right. I remember taking a plane from Denver back east, and looked out over the prairie, and thinking..."where is everybody?" haha Link to comment Share on other sites More sharing options...
whitemountainhiker Posted March 13, 2011 Share Posted March 13, 2011 Here's some info about nocturnal tornadoes. I'm not exactly sure what they define as nocturnal for the map but it gives a general idea. http://www.niu.edu/P...v/tornado.shtml I think it is midnight to dawn, because that is what is in the title. But I would think dusk to dawn makes more sense, though it is probably tougher to measure. Link to comment Share on other sites More sharing options...
Hoosier Posted March 13, 2011 Author Share Posted March 13, 2011 I never really thought of parts of the south as a highly densely populated area, but compared to the midwest, minus some of the bigger cities, that has to be right. I remember taking a plane from Denver back east, and looked out over the prairie, and thinking..."where is everybody?" haha Link to comment Share on other sites More sharing options...
Bozart Posted March 13, 2011 Share Posted March 13, 2011 This reason may be a bit more controversial, but what about education, meaning....actually knowing what a tornado warning means, and taking it seriously. There is only so much the weather service can do. I cannot say for sure that people who live there take the warnings seriously, but sometimes I wonder. And I'm not only talking about people in the south. All you have to do is check out youtube and watch videos of people putting themselves in harms way (the latest tsunami, floods, etc etc). Way back in 1972, John Sims (psychiatry, U of Chicago) and Duane Baumann (geography, Southern Illinois U), noted in an article* published in Science that "the number of tornado-caused deaths in the South is strikingly higher than it is in the remainder of the nation." To try to understand why, they administered a sentence-completion survey to 57 participants in Illinois and Alabama, and found pronounced differences in how residents of the two states react to severe-weather bulletins. E.g., in sentence completions for the stem, "During the time when a tornado watch is out, I..." residents of Illinois were five times more likely than Alabamians to report taking specific safety precautions. The Southerners were more likely to just consign themselves to God's will and go about their business, hoping (praying) for the best. I wonder how much of that kind of cultural disparity is still at play, four decades later, in people's responses to weather hazards. *Sims, John H. and Duane D. Baumann. "The Tornado Threat: Coping Styles of the North and South." Science, New Series, Vol. 176, No. 4042 (Jun. 30, 1972), pp. 1386-1392. Link to comment Share on other sites More sharing options...
Thunder Road Posted March 13, 2011 Share Posted March 13, 2011 This reason may be a bit more controversial, but what about education, meaning....actually knowing what a tornado warning means, and taking it seriously. There is only so much the weather service can do. I cannot say for sure that people who live there take the warnings seriously, but sometimes I wonder. And I'm not only talking about people in the south. All you have to do is check out youtube and watch videos of people putting themselves in harms way (the latest tsunami, floods, etc etc). Driving through a town in Kansas when a TOR was out and sirens were going off I saw almost the entire town out of their homes looking for the tornado. Thankfully there was no tornado, but I found that very interesting. Link to comment Share on other sites More sharing options...
hm8 Posted March 13, 2011 Share Posted March 13, 2011 Driving through a town in Kansas when a TOR was out and sirens were going off I saw almost the entire town out of their homes looking for the tornado. Thankfully there was no tornado, but I found that very interesting. Shows like Storm Chasers probably don't help the matter... Link to comment Share on other sites More sharing options...
SluggerWx Posted March 14, 2011 Share Posted March 14, 2011 I think the best way to look at tornado frequency is to compare the # of TOR warnings in a siloed urban area with RADAR coverage year-over-year. Way more tornadoes happen, and have always happened, than are reported. But, if we strip the data down to areas that do have the bandwith to report and then survey, maybe we get a clearer picture of the trends. Year-over-year in these silos also needs to be adjusted for 'tornadoflation'- more chasers each year means more visual reports and improved radar tech means more issued warnings. I think Stormchasers is 100% beneficial ('long-run') for the advancement in tornadoes because the increased exposure in the MSM will allow for increased investment in R&D to meet the public's interest level. IMO, southern states need 2x to 3x more dopplers that input data into a central server and export a clearer line of sight into approaching systems. Varied elevation in terrain and centralized city skyscrapers can hide/skew an approaching storm if the RADAR is in the NE proximity to the city. IMO, Nashville's low def doppler is in the world's worst position. Sent from my Droid using Tapatalk Link to comment Share on other sites More sharing options...
Ian Posted March 14, 2011 Share Posted March 14, 2011 dc area mini tornado alley ftw Link to comment Share on other sites More sharing options...
AtticaFanatica Posted March 15, 2011 Share Posted March 15, 2011 I think Stormchasers is 100% beneficial ('long-run') for the advancement in tornadoes because the increased exposure in the MSM will allow for increased investment in R&D to meet the public's interest level. I really don't think that increased media coverage has that much of an effect on the amount of funding NSF steers towards tornado research. The show was always pretty bad at accurately depicting what was going on in the tornado research community anyway. Their treatment of V2 was fleeting, at best, and the idea that the research (if you want to call it that) Reed and/or Sean are doing is going to increase tornado warning times, for example, is not one to be taken seriously. Naturally, it's not unexpected that DC would present the information that way, it makes for much more compelling television, but I doubt NSF funders and reviewers really care all that much. NSF does like media coverage, of course, and that was probably part of the reason TWC was welcomed to come out in the field for V2. Regardless, nothing to the scope of V2 is going to be funded for a long time considering the amount of data that were collected and the amount of money that was spent on the project. Link to comment Share on other sites More sharing options...
WxUSAF Posted March 15, 2011 Share Posted March 15, 2011 The bullseye around Norman, OK is complete observational bias due to the high density of meteorologists in the area. I'm sure reality is something else. Link to comment Share on other sites More sharing options...
Cajun Thunder Posted March 20, 2011 Share Posted March 20, 2011 Interesting how the killer tornadoes has two max gridpoints, near Birmingham, AL, and western TN, meanwhile the OKC area has the most significant severe weather reports in the country. Do you think that has to do with less storm cellars in Alabama and Tennessee, or people just don't take the warnings seriously there? West Tennessee tornado deaths have several factors. No storm cellars (or not many)...prefabricated homes and trailers...just to name two. Most of the tornado deaths...and most of the tornadoes...in West Tennessee in the last 20 years have been in the overnight hours. The warnings are taken seriously by most people in West Tennessee and the surrounding area. But not being able to see the storms coming at you is certainly a contributing factor. Link to comment Share on other sites More sharing options...
Itunis Posted March 20, 2011 Share Posted March 20, 2011 Driving through a town in Kansas when a TOR was out and sirens were going off I saw almost the entire town out of their homes looking for the tornado. Thankfully there was no tornado, but I found that very interesting. I wonder sometimes if the number of "false alarms" have something to do with apathy regarding tornado warnings in my area. We tend to have several tornado warnings a year, and usually severe t-storm criteria isn't met. The general attitude among my friends and family is that when the siren sounds, it'll rain harder and get a little breezy. The EF2 tornado that hit downtown ATL a couple years ago sent a warning that tornadoes can hit urban areas, but people here still think they are limited to the midwest and no-name towns in Alabama. Interesting that the total number of tornadoes map confirms my hunch that storms seem to "die out" right when they cross from AL to GA. Any possible reason for this? Link to comment Share on other sites More sharing options...
SluggerWx Posted March 24, 2011 Share Posted March 24, 2011 Ever seen the stats for how many folks joined Naval Aviation or the Air Force after Top Gun was released? I'm not saying the increased attention won't continue to drive yokels out to chase the chasers, it will, but I am saying increased attention gives some long-run upside that a Tornado 'Einstein' emerges. Sent from my Droid using Tapatalk Link to comment Share on other sites More sharing options...
Cfa Posted March 27, 2011 Share Posted March 27, 2011 I wonder sometimes if the number of "false alarms" have something to do with apathy regarding tornado warnings in my area. We tend to have several tornado warnings a year, and usually severe t-storm criteria isn't met. The general attitude among my friends and family is that when the siren sounds, it'll rain harder and get a little breezy. The EF2 tornado that hit downtown ATL a couple years ago sent a warning that tornadoes can hit urban areas, but people here still think they are limited to the midwest and no-name towns in Alabama. Interesting that the total number of tornadoes map confirms my hunch that storms seem to "die out" right when they cross from AL to GA. Any possible reason for this? Similar thing here, I've been in countless Tornado Warnings yet it's almost always nothing but a strong thunderstorm. That all changed last year, NYC had 3 Tornadoes as well a microbursts, this all happened no more than 5 miles from me so I saw a lot, if I didn't stay home that day for other reasons I would've been right in the action (probably outside too on my way home). We got strong winds and all of that but not the 100+ mph winds just a couple of miles to our north. In 2007 I was asleep during the EF2 that hit Brooklyn/Staten Island. NYC doesn't have Tornado sirens so how would anyone know unless they were by a TV, I think that's why so many people tend to be shocked since it's almost like a random event. I'll be more aware now as opposed to every warning meaning just another thunderstorm of a specific intensity. Link to comment Share on other sites More sharing options...
mnchaser Posted March 28, 2011 Share Posted March 28, 2011 Those first maps are some ancient data, just think back how active the 2000s have been! Climo is changing, we aren't in the 80s and 90s anymore. This is a new era! Last year speaks for its self. Minnesota had more tornadoes then any state in the country, even Texas! Link to comment Share on other sites More sharing options...
AtticaFanatica Posted March 28, 2011 Share Posted March 28, 2011 This is a new era! Last year speaks for its self. Minnesota had more tornadoes then any state in the country, even Texas! The new tornado alley IMO. Link to comment Share on other sites More sharing options...
tacoman25 Posted March 28, 2011 Share Posted March 28, 2011 The first map illustrates the mini-tornado alley that exists just east of the Denver area. Not a highly populated area at all, either. The tornados here tend to be weak, but are quite numerous compared to most parts of the country. Link to comment Share on other sites More sharing options...
LocoAko Posted March 28, 2011 Share Posted March 28, 2011 Similar thing here, I've been in countless Tornado Warnings yet it's almost always nothing but a strong thunderstorm. That all changed last year, NYC had 3 Tornadoes as well a microbursts, this all happened no more than 5 miles from me so I saw a lot, if I didn't stay home that day for other reasons I would've been right in the action (probably outside too on my way home). We got strong winds and all of that but not the 100+ mph winds just a couple of miles to our north. In 2007 I was asleep during the EF2 that hit Brooklyn/Staten Island. NYC doesn't have Tornado sirens so how would anyone know unless they were by a TV, I think that's why so many people tend to be shocked since it's almost like a random event. I'll be more aware now as opposed to every warning meaning just another thunderstorm of a specific intensity. You've had "countless" tornado warnings in NYC? Link to comment Share on other sites More sharing options...
tacoman25 Posted March 28, 2011 Share Posted March 28, 2011 Those first maps are some ancient data, just think back how active the 2000s have been! Climo is changing, we aren't in the 80s and 90s anymore. This is a new era! Last year speaks for its self. Minnesota had more tornadoes then any state in the country, even Texas! Certainly not representative of the 2000s. EDIT: I can only find the data from 2000-2005, but TX had more than three times as many tornados as MN 2000-2005. Link to comment Share on other sites More sharing options...
tacoman25 Posted March 28, 2011 Share Posted March 28, 2011 The new tornado alley IMO. Why do you think that? The southern plains/southern Mississippi Valley region has the most strong tornados now, just as they have in the past. Link to comment Share on other sites More sharing options...
AtticaFanatica Posted March 28, 2011 Share Posted March 28, 2011 Why do you think that? The southern plains/southern Mississippi Valley region has the most strong tornados now, just as they have in the past. Maybe my sarcasm skills are lacking today. I don't think that. Link to comment Share on other sites More sharing options...
tacoman25 Posted March 29, 2011 Share Posted March 29, 2011 Maybe my sarcasm skills are lacking today. I don't think that. Ah, ok. Never know on here. Link to comment Share on other sites More sharing options...
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