BAMOS March 2017
18
Article
Recent severe weather events in the Australian Capital Territory
Gavin O’ Brien, Southside Weather Watch( ACT) southsidewhract @ gmail. com
I operate a Personal Weather Station( PWS) which is a Davis Vintage Pro 2 with sensors communicating by wireless link to a Console on my office. In addition, I also operate a manual weather station with a temperature screen modelled on the conventional Stevenson Screen and Marquis rain gauge located on a grassed plot on the upper level of our back garden. A Maximum Analog Dial Anemometer is co-located with the Davis Anemometer, attached to the top of a guyed mast whose base is anchored on the upper end of the rear veranda roof. The sensors are about nine metres above ground level. The sensors have a good exposure in all directions, except the sector from east through north east as we are located on the southwest slope of Gilmore Hill whose summit, about 15 metres higher than the site, is located about 350 metres to the east north east. There is a mercury barometer adjacent to my office. It is set to station level readings( 662 metres above mean sea level).
Observations are made at 0900 and 1500 local time daily, with special observations when unusual or severe weather occur. The PWS transmits data to a data logger set at five minute intervals, which in turn transmits the information to a personal computer. The data are sent via the internet to the Weather Underground web site in real time, with the station name“ Gilmore North”. Manual observations are entered into the UK Met Office WOW website operated by the Bureau of Meteorology, twice daily following the observations. A Meteorological Log for the 0900 and 1500 Observations are kept as paper copy and filed. I am a Storm Spotter for the Bureau of Meteorology.
Severe Thunderstorm and hail storm in the Tuggeranong Valley ACT 29 January 2016.
Synoptic Situation The Synoptic Analysis for 11:00 a. m. 29 January 2016( 0000 UTC)
Figure 1( above). Mean sea level pressure conditions over Australia, 0000UTC 29 January 2016. Figure 2( below). Loop of 850hPa, 500hPa and 250 hPa conditions over Australia, 0000UTC 29 January 2016. Images: Australian Bureau of Meteorology.
A trough extended from north west Queensland through central New South Wales to a low pressure system, 1002 hPa located over central Bass Strait, separating warm moist tropical air flowing southward around a 1023 hPa high system. This system was centred over the southern Tasman Sea, while another high