Tornado questions

[Cookie]

first one.

whats the longest lasting tornado? from when it touches the ground to when it completely disappears?

second one.

mainly for the guys who go storm chasing do the vehicle's get fitted with extra strength windscreens etc and what other modifications do the vehicle's get?

and finally whats the biggest in size tornado?

thanks in advance cookie

[Lightning Hunter]

The answer to the first question is probably the 'Tri-State' tornado in 1925, USA. It lasted over 3 hrs and travelled over 200 miles, see here:

http://en.wikipedia.org/wiki/Tri-State_Tornado

As for the second question, well I've seen some high profile chasers such as Warren Faidley using grills/mesh for their windscreens, but I think most just try to avoid damaging hail and keep a pair of safety goggles in the car just in case :o

Edited April 11, 2008 by Lightning Hunter

[Cookie]

thanks mate for answering those 2 questions

[Gorky]

The Tristate tornado is listed as the longest but there is a lot of evidence to support the fact that it was a tornado family rather than 1 continuous track. As detailed storm surveys were not carried out back in 1925 we'll never really know. Due to the nature of tornados they are very unlikely to stay on the ground for that long before cycling, but it had a very high forward speed which may well have helped with the track length.

Some more recent and well documented long trackers were the Arkansas tornado of Feb 5th this year at 123miles and long track tornados in Mississippi (F4 - 128miles) and North Carolina (F3 - 160miles) during the November 1992 outbreak.

The widest tornado by damage path was the Hallam, Nebraska tornado of 2004 at 2.5 miles. The Mulhall Tornado of May 3rd 1999 had a larger measured max wind radii then any other sampled with damaging winds estimated out to 4 miles from mobile Doppler radar but it was over open fields and had very little to damage at it's widest. The Hallam tornado was never measured by similar equipment but as it went through town, the damage caused by lower end winds was noted. For comparison, the Greensburg tornado last year was a 'only' 1.7 miles across with the next tornado in that family near Hopewell a 'mere' 2.2 miles in diameter

[Cookie]

only 1.7 and the damage that caused!!

thanks gorkey

[kold weather]

Actually I have a question, how can this happen:

[crimsone]

Wow! I'd like to know that myself - that's incredible!

[NL]

only 1.7 and the damage that caused!!

thanks gorkey

What do ya mean ONLY 1.7...!! Thats massive considering most tornadoes are a few hundred

yards across..!!

[Gorky]

I may have been kinda joking with my 'only' description but the fact that the Hallam tornado almost 50% wider than the Greensburg Tornado is pretty amazing considering the pictures we've seen of the the Greensburg wedge. It's a shame there is very little video of the Hallam tornado at it's widest (only one that I know of and that was taken from inside the tornado!)

[kold weather]

So the 1999 tornado was estimated to have circulation winds out to 4 miles according to the doppler radar?!

If that was the case that is mental...for comprasion the smallest eye from an atlantic hurricane was Wilma...its eye was only 3 miles wide...smaller then that tornado, madness!

[Cookie]

What do ya mean ONLY 1.7...!! Thats massive considering most tornadoes are a few hundred

yards across..!!

I meant to the others that we're listed

[Lightning Hunter]

Actually I have a question, how can this happen:

That footage is amazing, I've seen it loads of times but it never fails to impress. Must be some great dynamics going on to create that. I've seen 'satellite' tornadoes etc, but to have two join like that.....wow

[Cookie]

we need to get paul to notice this thread

[0000]

The answer to the first question is probably the 'Tri-State' tornado in 1925, USA. It lasted over 3 hrs and travelled over 200 miles, see here:

http://en.wikipedia.org/wiki/Tri-State_Tornado

As for the second question, well I've seen some high profile chasers such as Warren Faidley using grills/mesh for their windscreens, but I think most just try to avoid damaging hail and keep a pair of safety goggles in the car just in case

that link was fascinating,so I presume that was a perfect storm scenario for that 1925 tornado?

[Roger J Smith]

I've seen the map for that date in the archives at Environment Canada, not sure if it is reproduced on the internet anywhere. Of course they didn't have upper air maps in 1925. The surface map is a fairly obvious tornado event but not some massive superstorm, I recall it as something like a wide open wave from a low of about 1002 mbs. Some of the research variables were quite high in the geomagnetic realm. The winter of 1924-25 was not very severe in eastern and central N America so I assume the spring onset was early in Illinois and Indiana.

[0000]

I've seen the map for that date in the archives at Environment Canada, not sure if it is reproduced on the internet anywhere. Of course they didn't have upper air maps in 1925. The surface map is a fairly obvious tornado event but not some massive superstorm, I recall it as something like a wide open wave from a low of about 1002 mbs. Some of the research variables were quite high in the geomagnetic realm. The winter of 1924-25 was not very severe in eastern and central N America so I assume the spring onset was early in Illinois and Indiana.

thank you for that RJS

[0000]

Are waterspouts and tornados the same creature ?

[BrickFielder]

The most simple answer is that they are the same. The complex answer is that both can be formed from two different processes with waterspouts tending to be formed from a vertical vorticity source rather than a horizontal one. Typically the big tornadoes in the US are formed in association with a horizontal vorticity source with low level wind speed shear playing an important role along with strong updrafts. In the UK as in Florida we have a bountifull supply of vertical vorticity sources, whether from thermal updrafts ,coastal cliff edges,onshore wind convergence, hills etc which can play a role in short lived weak tornadoes or funnels (spout type). Either type can form over water or land and one can change into the other under the right circumstances. All are usually shortlived unless there is updraft and downdraft seperation (moderately strong mid level winds) and there is a mid level mesocyclone (super cell formed from mid level winds changing direction with height) to keep the vortex going.

See the Estofex Forecasting Severe Thunderstorms information found under the Research and Education Link on the left for more details.

Estofex