SPC Tornado Outbreak Browser

[chrisbroyles]

Wow what a awesome tool. I have one question though. It appears as though some of the events are missing tornadoes? May 13, 1995 for example, a high risk day here in Illinois, there were 2 F4 tornadoes (one near Raritan/Roseville and the other near Ipava), it only shows the Ipava storm tornadoes? I realize this was 21 years ago, however this isn't the only source I've seen that leaves these tornadoes out. I'm curious as to why this is, if anyone has insight into this, I'd greatly appreciate it. Especially considering this event is one that is of great interest to me, probably one of the few that sparked my interest in weather. View attachment 11622


Here is the NCDC article on the missing F4 in this database: https://www.ncdc.noaa.gov/stormevents/eventdetails.jsp?id=10320748

There was also another significant F2 that came after that across Southern Knox County in which I don't see shown.

As was mentioned before, the Knox County F2 is already in the database. Added the Raritan F4 tornado into the SPC database yesterday. A script will be rerun in a couple of weeks and the correction will be made official. I have not had a chance to update the Violent Tornado Webpage for the Raritan F4 tornado but hope to get it done within the next couple of months.

 

[Drew Terril]

I just now saw this. Very, very nice.

 

[chrisbroyles]

Wow what a awesome tool. I have one question though. It appears as though some of the events are missing tornadoes? May 13, 1995 for example, a high risk day here in Illinois, there were 2 F4 tornadoes (one near Raritan/Roseville and the other near Ipava), it only shows the Ipava storm tornadoes? I realize this was 21 years ago, however this isn't the only source I've seen that leaves these tornadoes out. I'm curious as to why this is, if anyone has insight into this, I'd greatly appreciate it. Especially considering this event is one that is of great interest to me, probably one of the few that sparked my interest in weather. View attachment 11622


Here is the NCDC article on the missing F4 in this database: https://www.ncdc.noaa.gov/stormevents/eventdetails.jsp?id=10320748

There was also another significant F2 that came after that across Southern Knox County in which I don't see shown.

The Raritan, Illinois F4 tornado on May 13, 1995 has been added to the Violent Tornado Webpage and to the SPC database as well. The Knox County tornado from the same day was already on the Violent Tornado Webpage and in the SPC database. Thanks for bringing these tornadoes to our attention.

 

[Brandon Skalniak]

Is this website no longer being updated? The last event that was added was Pilger in 2014.

 

[Jeff Duda]

Is this website no longer being updated? The last event that was added was Pilger in 2014.

Half joking, but have there been any events worth adding since then? We haven't had many violent class tornadoes since 2014. What, a couple of isolated EF4s...(some of which occurred in March 2020, which I wouldn't expect to have been added yet anyway).

 

[Lou Ruh]

Chapman, maybe?

 

[Mark Blue]

Just a quick internet search defines a tornado outbreak as having 6 - 10 tornadoes from the same synoptic scale system. I didn’t chase Chapman so am not that familiar with the event. I see it was a long track tornado but I’m not sure if it meets the definition of an outbreak per se.

 

[Lou Ruh]

Just a quick internet search defines a tornado outbreak as having 6 - 10 tornadoes from the same synoptic scale system. I didn’t chase Chapman so am not that familiar with the event. I see it was a long track tornado but I’m not sure if it meets the definition of an outbreak per se.

The SPC tool seems to not use that definition. It has 2 columns to choose from ... >= 4 Violent Tornadoes in 3 days ... >=1 Violent Tornado in 1 day ... so, it seems to qualify for inclusion (it was rated an EF4). Not to mention that there were a total of 4 tornadoes that day from that storm and a total of 11 in KS (based on filtered reports at SPC), a day after the Dodge City tornado-fest (arguably the same synoptic scale system).

 

[Mark Blue]

I just emailed Mr. Broyles at the SPC for clarification. Hopefully I’ll hear back from him or he’ll post an update here if he has time.

 

[chrisbroyles]

Thanks for the questions. On the Violent Tornado Outbreak webpage, there are two columns at the right. One column displays all major violent tornado outbreaks in the U.S. To be a major violent tornado outbreak, the case had to have at least four F4-5s (EF4-5s) within a 72 hour period (12Z to 12Z). The other column is for more localized violent tornado outbreaks in the U.S. The more localized cases had between one and three F4-5s (EF4-5s) in a 24 hour period (12Z to 12Z). While most of the cases are true tornado outbreaks, a few may not be considered outbreaks by many people's standards if the total number of tornadoes is too small. The definition of outbreak ranges widely depending upon who you talk to. I've seen the word "tornado outbreak" refer to cases with a minimum total as little as six tornadoes or as many as 50 tornadoes. I ranked the major outbreaks with at least four violent tornadoes using an equation that considers tornado number, sigtor number and violent tornado number for each case. You can display the major tornado outbreaks in ranked order by using the menu above labeled "Options".

The Pilger, Nebraska case is the last case because the data collection process is very tedious. It takes an incredible amount of work to process each case. Sometimes it can take a week or two just to process one case. And to update the webpage would be a major undertaking that would probably require at least 2 months to complete. Programming languages can change over time making image creation of the required specifications even more difficult. Although there are many new cases that qualify, I just have not had the time to process the new cases. There are literally over a half million images that are stored online. The amount of space taken for the webpage is about 35 gigabytes. So making the database larger is problematic. Finding the time to add new cases is difficult. Right now I am involved in a major radar project looking at tornadogenesis in over 200 violent tornadic supercells. So I just have not had the time to update the violent tornado webpage. But I am glad that people are using it.

If you have any other questions, please don't hesitate to ask.

Chris

 

[Warren Faidley]

Impressive collection of data. I'll spend hours obsessing over it eventually.