With John and others obviously involved in the 2002 WSSC, I thought it might
be worth bringing to the lists attention the extremes of rainfall/moisture
that Australia has witnessed in the last couple of days. Foremost, Exmouth
under what might very loosely be called a NW cloud band - but clearly was
not in the conventional sense received a June WA state record rainfall of
304.6mm to 9am Tuesday. Apparently, the town power station was flooded, and
witnesses who live through TC Vance verified that it was wetter than during
that event (see http://abc.net.au/news/newsitems/s573115.htm for example).
The previous June WA record was 272.2mm Urala (11/6/1992 - thanks Blair).
Falls near 100mm were quite widespread, but with the rain band substantially
tracking along its axis and the sparsity of stations, it is not surprising
that Exmouth which would appear to have "scored" a near direct hit achieved
such a high total.

Mechanistically, the rain coincided with a tongue of exceptionally moist air
(precip water near ~55mm,
http://serva.vic.bom.gov.au/cgi-bin/dfcgi/difacs.cgi?0097) [image at time of this message] extending from
the Indian Ocean onto the coast, and a small but well organized area of
rapid vertical motion omega values ~-40 (- I'm sure John or someone can come
up with a nice explanation involving Q vectors or IPV!). From a climate
perspective, this rain event coincides with an Indian Ocean NW of Australia
which is quite possibly the warmest we have ever witnessed in early winter
(see http://vortex.ho.bom.gov.au/ocean/charts/SSTanom.gif). [image at time of this message]

On the flip side, the enormous semi permanent high which has firmly lodged
itself near Victoria for ~6 weeks, which is linked to the very strong falls
in the SOI in the last month, has seen exceptionally dry air become
established over much of central Australia. Indeed, yesterday, the
precipitable water analysis shorted a minimum of 1mm in the NT which I can't
imagine happens to often (comments?), and which has been reflected in the
very large diurnal temperature ranges (widely ~20C) which have been common
place in recent days (e.g., Yesterday, 0 to 20C Alice Springs, -3 to 16C
Wangarratta, -4 to 17 Canberra, -2 to 18C Renmark,... etc).
Regards,

David