Storm Australian Severe Weather Forum

Severe Weather Discussion => General Weather - all topics not current severe weather. => Topic started by: John Allen on 07 January 2009, 12:03:27 AM

Title: A reflection of the 1998 Sydney to Hobart disaster
Post by: John Allen on 07 January 2009, 12:03:27 AM

Im going to do a bit of a summary of this event for a bit of fun and everyones benefit, i'm sure we all remember just how bad this system was for the race and the influence it has had on the yachting community.

This memory was sparked by seeing footage the other day of a waterspout which impacted the race leaders ichiban and nicorette. The structure on the NW flank of this particular thunderstorm was rather interesting in my mind, with a corkscrewed strong mesocyclone appearance. Directly under this 'mesocyclone' was the tornado (waterspout), which appeared to be a stovepipe of some size. I will be attempting to dig up some old charts and data to assess whether indeed this storm had the potential to be a supercell at sea, and thus produce a true tornado type waterspout as opposed to the standard kind. Before even assessing these charts I would argue that there is significant potential for this to be a supercell given:
A) The rapidly developing bomb low to the west was tilted eastward at 500hPa similar to that noted for Artic hurricanes. This entails that strong upper level cooling would be present over the prefrontal trough.
B) A prefrontal trough extending northwards was present to provide forcing.
C) With the upper level low significant directional and speed shear was likely present, with N-NE surface backing to S-SW at 500hPa.
D) Presence over the ocean, together with subtropical moisture inflow would lead to a highly moist conditioned enviroment.

Over land these conditions would likely lead to supercell thunderstorms. So Ill dig some more information up and get it up here. Feel free to comment folks.

Title: Re: A reflection of the 1998 Sydney to Hobart disaster
Post by: Michael Bath on 07 January 2009, 03:03:22 AM

Hi John - the tornado was 26 Dec 2001 - there is a thread here (http://www.australiasevereweather.com/forum/general-weather-all-topics-that-are-not-current-severe-weather-should-be-posted-here/sydney-to-hobart-yacht-race-supercell-and-tornado-26-dec-2001/) which you can add to.

Dec 1998 was the bomb low which led to all the deaths - maybe discuss that one here?

regards, Michael

Title: Re: A reflection of the 1998 Sydney to Hobart disaster
Post by: Jimmy Deguara on 07 January 2009, 03:14:22 AM

Actually can this thread be remodified and fixed given it is fresh and not response thanks John/Michael.

I am heading out in 5 minutes - delete my post. Members need not reply until we have the thread fixed.

Jimmy