Storm News
and Chasing

Main Index Home Page Stock Weather Photos Australian Severe Weather Forum Storm News and Storm Chasing Reports Tropical Cyclones / Hurricanes / Typhoons Weather Data and Links Wild Fires / Bushfires Weather Observation Techniques Weather Picture Catalogue Tornado Pictures and Reports Stock Video Footage and DVDs for sale
Mesocyclone Develops on a Triple Point in Western Sydney: Monday 31st October 2005
Report compiled by Jimmy Deguara and Michael Bath

October showed some conditions that put western Sydney in a favourable situation for severe storms due to high CAPE, excellent deep layer shear (for Australian conditions) and reasonable moisture profile. But nothing would prepare me and Jeff Brislane for what we would witness from different vantage points!

After watching video, it is interesting that there was pronounced and prolonged rotation - so I was not imagining things! In fact some tornadic funnels formed under the main centre of rotation! This mesocyclone developed on a triple point so it will be interesting to see the doppler images for this time! Given the high CAPE and moderate wind shear environment, and of course the low condensation levels, in hindsight it is not unexpected.

Obviously a triple point was evident within the environment of the storm - well the storm developed along a triple point. With high CAPE, the upmotion was incredible and sustained for at least 30 to 40 minutes and likely longer. The interesting behaviour began earlier but it seemed to become hidden by rain for a little while. Then a shelf cloud emerged so I prepared for an evacuation in order to remain ahead. But the storm with shelf cloud reorganised due to stronger deep inflow and the rotation once again developed. It was amazing to observe inflow from the east where I was and even northeast on the northern side and southeast on the southern side of the 'mesocyclone'! I am going to investigate this one further with the Bureau of Meteorology.

If you have any reports or photos you would like to provide about this storm, please send an email to Jimmy Deguara


From Bureau of Meteorology

  • Sydney local scale loop 0500z to 0930z 31/10/2005 (4pm to 8.30pm 31/10 local time)
  • Sydney medium scale loop 0200z to 1000z 31/10/2005 (1pm to 9pm 31/10 local time)

    Satellite Images

    From Weatherzone and Bureau of Meteorology

    11am to 10pm local

    31/10/2005 06z 5pm local

    Analysis Charts

    From Bureau of Meteorology

    31/10/2005 06z

    GFS Model Analysis

    From NOAA 31/10/2005 06z analysis

  • Liftex Index
  • CAPE
  • Relative Humidity surface
  • Relative Humidity 850 hPa
  • Relative Humidity 700 hPa
  • Relative Humidity 600 hPa
  • Relative Humidity 500 hPa
  • Relative Humidity 300 hPa
  • Temperature (C) surface
  • Temperature (C) 850 hPa
  • Temperature (C) 700 hPa
  • Temperature (C) 500 hPa
  • Temperature (C) 300 hPa
  • Winds (knots) surface
  • Winds (knots) 925 hPa
  • Winds (knots) 850 hPa
  • Winds (knots) 700 hPa
  • Winds (knots) 500 hPa
  • Winds (knots) 300 hPa
  • Winds (knots) 200 hPa

    Document: 200510-07.htm
    Updated: 18th December, 2005
    [Australian Severe Weather index] [Copyright Notice] [Email Contacts] [Search This Site]