2011 data edited

The SPC has made some changes to the 2011 data, which have been carried over here. While the tornado count changed for two states (1 more for Oklahoma, 1 less for Tennessee), the total tornado count for the year remained the same. A list of the changes:
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2011 data added

The Tornado History Project is happy to announce that year 2011 tornadoes have been added to the database*. There were 1692 tornadoes logged last year, which makes it the 2nd highest annual total on record. This brings the total number of tornadoes mapped on the site to 56,221, covering the period 1950-2011.

Unfortunately, it was also a very deadly year with 550 fatalities and 5479 injuries. To put that into perspective, the total number of fatalities for the previous ten years combined was 563. Some of the most notable tornadoes of the year were this F5 tornado that struck Joplin and surrounding areas in Missouri, and this F4 tornado that struck Tuscaloosa and surrounding areas in Alabama.
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Minor data change

Just noticed that the SPC made a very minor edit to their historical data file. As always, this change has been carried over to the Tornado History Project.

The tornado in question is 19681117.28.13, where the lift-off coordinates were changed from 30.8,-88.92 to 31.67,-89.93. While the data has been updated, this had no effect on the map since the approximate path was reproduced with data from the NCDC (see Enhanced Paths Explained), which already had the correct coordinates.

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2010 tornado data added

Just a quick note to announce that year 2010 tornadoes have been added to the database*. There were 1282 tornadoes added for last year, which caused a total of 45 fatalities and 701 injuries. The most noteworthy tornado of the year is this F4 on April 24 that tore through parts of Mississippi and Louisiana killing 10 and injuring 146 while causing an estimated $386 million in damages.

With this latest update, there are now 54,529 tornadoes to explore at the Tornado History Project.

* Thanks to the SPC for collecting and providing the data.

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Data updates

As you may know, the Tornado History Project uses data from the Storm Prediction Center’s (SPC) historical archive to generate maps and tables. So when the SPC updates their archive with new stats and information, the Tornado History Project incorporates those changes into our database. A quick summary of the recent changes follows:

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2008, 2006, 2000, and 1971 data updated

Just a quick note to document a few changes to the database where the SPC has modified data for past years:

A number of changes were made to 2008 records:

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2009 SPC Data Added

I am pleased to announce that 2009 tornado data has been added to the database. 1,156 tornadoes were added this year, bringing the total number of tornadoes in the database to 53,253. Just visit the front page to get started.

Note that, at the time of writing, the SPC has not assigned sequential national or state tornado numbers. However, they are using temporary non-sequential tornado numbers for the national number, which has been carried over here. Once the SPC officially sequences the tornadoes, our data will be updated.

2006 and 2007 data updated

In a previous post, I noted that there were some significant revisions to the 2006 and 2007 SPC historical tornado archive (the source of data for this site.)  According to Gregorgy Carbin, the Warning Coordination Meteorologist at the SPC, the National Weather Service changed the way they reported latitude and longitude values in October of 2006.  The person responsible for maintaining the SPC archive at the time inadvertently continued to convert the lat/lon values from minutes/seconds to decimal degrees, even though they were now being reported by the NWS in decimal degrees.  This unnecessary conversion caused the lat/lon values to be slightly off.  When this was discovered in late 2008, he corrected the lat/lon values, while also taking the opportunity to do some additional quality control.

As of last Saturday night (10/10/2009), these changes have been incorporated into the Tornado History Project database.  Although not a comprehensive list, some key changes are listed below:

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2008 SPC Data Added

I am pleased to announce the addition of the 2008 tornado data from the Storm Prediction Center (SPC). Simply go to the search page to have a look.

I should note that the SPC has not assigned state tornado numbers this year (as of the time of writing.) Although a minor issue, this does affect how tornado index numbers* were chosen for tornadoes. In past years, the index number was generally a mix of the date, state FIPS code, and state tornado number (see “2006 Data Added to Tornado History Project Database”. However, since the state tornado number has not yet been assigned, the general SPC tornado number was used instead.

One more note on the archive files posted by the SPC this year…I noticed some significant revisions to the 2007 and 2006 data (mainly tornado number and latitude/longitude revisions), but those changes have not yet been incorporated here. So, be on the lookout for another update to address this in the near future, as well as several other general updates to the Tornado History Project.

* Index numbers are generated by the Tornado History Project to uniquely identify tornadoes within the site. The index number is not part of the official SPC data.

The SPC Archive and the Tornado History Project

One of my favorite recently added features of the site (see Major Upgrade to Tornado History Project 7/19/08) is the ability to easily correlate each tornado in the Tornado History Project database to the original line (or lines) in the Storm Prediction Center (SPC) archive. Why is this important? It is not uncommon for users to email me with a comment such as:

The county listed for tornado X is wrong. It should be Y – I know because it hit my house. Why don’t you do a little research before putting this on the internet?.

Yikes! While I want to know when there is a suspected error in the data, I also want to be clear where the information comes from. So, this will make it much easier to tell if the Tornado History Project is accurately reporting the data as given in the original SPC archive. In short, it adds transparency to the site and takes the mystery out of where the data comes from. And in cases where the Tornado History Project has changed any of the data (which is very rare), notice is given.

Let’s take a look at where you can find this info. On any individual tornado map page, all stats for that tornado are shown in an easy to read format immediately under the map as shown in the picture below. The last line of the section shows the actual text from the SPC archive used to generate those stats.

Of course, being able to actually see the original line from the SPC archive isn’t quite enough. It is also important to know how to read and interpret the information. So, a link is also given to the SPC instructions that explains what each piece of information actually means.

I should point out that there is one situation in which the approximate path shown for a specific tornado may not actually be based on the data in the SPC archive. Please see a previous blog entry (Enhanced Paths Explained 7/19/08) for more information.

And finally, there is one more note on this…Users must be logged in to see the corresponding line (or lines) from the SPC archive, so if you don’t see anything it, just login or register for a free account and you’ll be all set.