mersenneforum.org  

Go Back   mersenneforum.org > Fun Stuff > Lounge

Reply
 
Thread Tools
Old 2021-09-11, 15:36   #78
masser
 
masser's Avatar
 
Jul 2003
wear a mask

2·863 Posts
Default

Quote:
Originally Posted by Uncwilly View Post
Those areas with high counts of twisters, how many above EF-1's do the get? How does that stack up vs "Tornado Alley" in the US of A?
Not well. First of all, the shape is rather inconvenient. And then, the bloody things won't stop moving. It's a nightmare.
masser is offline   Reply With Quote
Old 2021-09-11, 16:23   #79
kriesel
 
kriesel's Avatar
 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest

10110100010112 Posts
Default

Quote:
Originally Posted by masser View Post
Not well. First of all, the shape is rather inconvenient. And then, the bloody things won't stop moving. It's a nightmare.
Sounds like a job for Pecos Bill.
kriesel is online now   Reply With Quote
Old 2021-09-12, 01:35   #80
Dr Sardonicus
 
Dr Sardonicus's Avatar
 
Feb 2017
Nowhere

3·5·331 Posts
Default

Quote:
Originally Posted by Uncwilly View Post
Quote:
Originally Posted by Dr Sardonicus View Post
Would you prefer square furlongs per fortnight?
No, I was amused by the whole notion of "tornadoes relative to land area." As long as it's "tornadoes per unit time per unit area" using the same units, the ratio between any two given areas will be the same. I take tornadoes per year per 10000 km2, as in this article, whose headline is, perhaps amusingly (my emphasis),
Quote:
England is tornado capital of the world! More twisters per square mile than other nation
The article says England averages 34 tornadoes per year, or 2.2 (per year) per 10000 km2.

That gave me an area of about 154000 km2, which (after consulting an atlas) appears to be roughly the combined areas of England and Wales.

An average of 34 tornadoes per year is more than a lot of us might expect for the UK - point taken. (It seems most UK tornadoes are weak and of short duration, but they're still tornadoes.)

But look what happens is we apply the idea of "tornadoes per year per 10000 km2 to Pantelleria, which just got hit by a tornado. Its area is 83 km2, so that one tornado gives roughly 120 tornadoes per 10000 km2 per year. Assuming Pantelleria hasn't had any other tornadoes in the last 50 years, over the last 50 years it has it averaged almost as many tornadoes per year per 10000 km2 as the UK; and over the last 25 years, it leaves the UK far behind - just from a single tornado.

Harris County, Texas has averaged about 4 tornadoes per year since 1950. Its area is 1777 mi2 which is about 4600 km2, which gives about 8.7 tornadoes per year per 10000 km2.

The US Deep South seems to be getting more frequent tornadoes in recent years, causing some folks to re-think the idea of a single "Tornado Alley" being a narrow swath of the Central Plains.

Quote:
Those areas with high counts of twisters, how many above EF-1's do the get? How does that stack up vs "Tornado Alley" in the US of A?
I have read in several places that most tornadoes in the UK are quite weak (as tornadoes go) and do not last very long.

I find it difficult to compare the severity of tornadoes in the US and the UK, because the US uses a damage scale, the Enhanced Fujita Scale (F0 - F5) while the UK uses a "pure wind-speed scale," the TORRO tornado severity scale (T0-T11). It seems, however, that with either scale, wind speeds are usually inferred from the damage, since direct measurements are generally not available.

I found conflicting figures for the wind speeds of the July 28, 2005 Birmingham tornado, the strongest in the UK in recent history.
Dr Sardonicus is offline   Reply With Quote
Reply

Thread Tools


All times are UTC. The time now is 23:34.


Fri Oct 15 23:34:48 UTC 2021 up 84 days, 18:03, 0 users, load averages: 1.50, 1.25, 1.29

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.