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Australian tornado climatology and information / Bulahdelah Tornado Report 1/1/1970

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Jimmy Deguara:
Hi,

Whilst perusing the internet in search of particular facts about tornadoes, I came across these resources which is quite interesting given it is wikipedia. Including is a table of tornado information and links:

http://en.wikipedia.org/wiki/List_of_Southern_Hemisphere_tornadoes_and_tornado_outbreaks

http://en.wikipedia.org/wiki/Bulahdelah_tornado

There are of course links to other segments from the original link above.

Regards,

Jimmy Deguara

Michael Bath:
I came across this as well the other day when looking up the dates for a couple of the other major events.

There was no info that I could find about the time the Bulahdelah tornado occurred. After plotting charts from the GFS archives it appears to have occurred between 00z and 06z. Pretty impressive getting such cold upper air at the beginning of January.

There are no satpics or soundings available (online) this far back in time for Australia.

01/01/1970 00z

Instability: Lifted Index

Relative Humidity: 0300 / 0500 / 0600 / 0700 / 0850 / 1000

Temperature: 0300 / 0500 / 0700 /  0850 / 1000

Winds (knots): 0300 / 0500 / 0600 / 0700 / 0850 / 0925 / 1000


01/01/1970 06z

Instability: Lifted Index

Relative Humidity: 0300 / 0500 / 0600 / 0700 / 0850 / 1000

Temperature: 0300 / 0500 / 0700 /  0850 / 1000

Winds (knots): 0300 / 0500 / 0600 / 0700 / 0850 / 0925 / 1000


Jimmy Deguara:
Michael,

What I find interesting about the year 1970 was that it was from what I recall statistically a cold winter - Richmond for instance acheieved its coldest morning on record of -8.3C. I assume that particularly cold air was advected north and perhaps made such a cut off low with such extreme temperatures possible that year.

That was one hell of a system!

Regards,

Jimmy Deguara

James:

Wow, that is a nice set-up alright! Thanks for digging out those links above MB.

A couple of things caught my eye looking over those charts above. I would have thought the RH for 1000 and 850 would have been a little higher than around 50%. Is there any record of the LCL for that day? Probably not but thought I'd ask. Second thing is watching the surface low really develop between 00z and 06z. Quite awesome to see it take shape with increasing wind speeds around it as the upper cold pool approaches.

Jimmy Deguara:
Hi James,

I have seen the actual report of this event and let me tell you the analysis was reasonably complex with a surface trough along the eastern part of the ranges. Supercells exploded along the line with cricket balls sized hail amongst a few of the storms. This storm for some reason developed very low bases and thence the giant tornado that followed!

Regards,

Jimmy Deguara

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