forgotten outbreak

[Dan Cook]

Being bored before class, I was digging around the SPC archives and found some semi big outbreaks that I didn't even know happened:

Feb 13 00 SE outbreak. 24 killed in Georgia

http://spc.noaa.gov/exper/archive/events/0...0213/index.html

I'm off to class, but I'll try to find more later.

 

[rdale]

There were 4 (four) tornadoes in Georgia... They hit primarily trailer parks and a few subdivisions in the middle of the night with no warning. That is not even close to a semi-small outbreak! Just because people die does not mean you had a tornado outbreak.

- Rob

 

[Carrie Halliday]

What is the criteria to have a tornadic event be considered an outbreak?

 

[rdale]

There is no formal definition... yet... Roger Edwards and the gang at SPC are proposing one:

http://ams.confex.com/ams/11aram22sls/tech...paper_81342.htm

 

[Sam Hunter]

I've been reading through some of the conference abstracts on outbreaks, and have been reading up on the May 2003 and the 1974 outbreaks, but I can't find much about what "leads up" to an outbreak -- are there pre-existing or extraordinary conditions of some sort that lead to this kind of weather, some peculiar jet stream activities, el ninos, etc that have been observed before outbreaks happen?

Sam

 

[Glen Romine]

Originally posted by Sam Hunter
I've been reading through some of the conference abstracts on outbreaks, and have been reading up on the May 2003 and the 1974 outbreaks, but I can't find much about what \"leads up\" to an outbreak -- are there pre-existing or extraordinary conditions of some sort that lead to this kind of weather, some peculiar jet stream activities, el ninos, etc that have been observed before outbreaks happen?

Sam

The correct terminology I think you are looking for is "synoptically evident", which is a combination of features often seen in significant severe weather events. You can probably search the web on your own to find the definition of this that suits your needs. It should be noted, however, that this synoptic scale favorable environment has smaller scale features embedded within it that frequently lead to the difference between an outbreak or not, with the latter dominating in most circumstances. Of course, not all outbreaks are synoptically evident - particularly ones that cover a relatively small spatial region, where again smaller scale features combine with the less-than-ideal larger environment to make it favorable on a local scale.

Glen

 

[Shane Adams]

What is the criteria to have a tornadic event be considered an outbreak?

My personal criteria is as follows.....

A concentrated area of one state (3-4 counties) = 10 or more tornadoes

A single state, statewide (tornadoes reported in multiple locations across the state) = 20 or more

After we're talking multiple states, it's pretty obvious whether it was an outbreak or not

 

[Sam Hunter]

Originally posted by Glen Romine


The correct terminology I think you are looking for is \"synoptically evident\", which is a combination of features often seen in significant severe weather events. You can probably search the web on your own to find the definition of this that suits your needs.

Glen

Yes, thank you -- I did find more information. And thanks for the notes on scale, that makes sense.

Sam

 

[David Draun]

speaking of outbreaks and synoptic scenarioes

NWS Chicago has released a paper about the tornado outbreak on 4/20/04. I thought that was very interesting reading. Here is the link, you must have acrobat reader or another pdf reading application.

http://www.crh.noaa.gov/lot/severe/20Apr04.../04slspaper.pdf

 

[Glen Romine]

Re: speaking of outbreaks and synoptic scenarioes

Originally posted by David Draun
NWS Chicago has released a paper about the tornado outbreak on 4/20/04. I thought that was very interesting reading. Here is the link, you must have acrobat reader or another pdf reading application.

http://www.crh.noaa.gov/lot/severe/20Apr04/04slspaper.pdf

Yeah, nothing real novel here though. I like Al P.'s usual assessments, but I was a bit disappointed with this one. It in many ways is a rehash of what Jon davies did for this case:

http://members.cox.net/jondavies3/042004il.../042004ilin.htm

I also don't agree entirely with his assessment of the case - but I haven't taken the time to put together my own, so I guess that makes me a hypocrite...lol. Well, it just relates to my own research, and i see this event a bit differently. Maybe someday I'll put something together on this case for others to hack at.

Glen

 

[Andrea Griffa]

In mitchell county was a tragedy: 18 dead in only one tornado....Somebody knows the scale?Maybe F5?

 

[rdale]

It was an F3, and killed 10. 8 more were killed in separate tornadoes during that event.

http://www.srh.noaa.gov/tae/tlh/mm5/SLS/go...shtml_gould.htm

 

[Andrea Griffa]

It was an F3, and killed 10. 8 more were killed in separate tornadoes during that event.

http://www.srh.noaa.gov/tae/tlh/mm5/SLS/gould_sls/Svrstmshtml_gould.htm

Oh an F3...Anyway seeing the radar, Mitchell county supercell is not very strong as reflectivity even if it shows good rotation with an evident inflow notch and hook echo....Howewer it isn't so much common that similar supercells produce so strong tornadoes.