|
The graphics and statistical information on this page fill gradually as they become available, with some not available until the next day.
The page is updated every 30 minutes at about 20 and 50 minutes past the hour.
For weather news as it breaks that is tagged and organised, use the links on the Weather and Climate Media Reports page.
 Lightning flashes on BoM satellite imagery
The BoM's Satellite Viewer has been upgraded to let you overlay lightning activity on an infrared cloud imagery background. After loading the viewer, select Lightning using the Layers button.
The lightning is plotted on a 2km by 2km grid on the chart, and the colour plotted indicates the intensity of lightning within 5km of the centre of each grid centre. The scale at the bottom shows five levels ranging from low intensity (two strikes within the last 10 minutes) to high intensity (ten or more strikes within the last 10 minutes). The lightning data is supplied by Weatherzone.
 Exceptionally high pressure pushes large areas towards drought
|
 Large parts of western WA, southern NSW, northern VIC and eastern TAS had their driest June on record this year. The much larger area with the "very much below average" shading had less rain than it would expect in one in ten years. BoM |
Australia has just completed its second-driest June since reliable rainfall records began in 1900, with large parts of the country having their driest. The bad news is that it's not going to improve in a hurry.
Persistent high pressure across southern Australia and the lack of cold fronts, which normally bring cloud and rain from the Southern Ocean during winter, were responsible for the national rainfall average being 62% below average. The area-averaged rainfall for Australia as a whole was just 8.8mm, only just above the 8.0mm in 1940 which was the driest June on record. VIC recorded an average of 13.7mm statewide, 77% below average and the lowest on record for the state. In its Australian Monthly Summary for June*, the Bureau of Meteorology says "Across the country, more than 100 stations with more than 50 years of observations have reported their lowest June rainfall total on record."
The remarkably persistent high pressure is a foretaste of things to come, with climate change pushing the sub-tropical ridge of high pressure farther poleward as the planet warms. Average pressure in winter in southern Australia has been gradually increasing over recent decades. The BoM says that mean sea level pressure (MSLP) "has been more than 5hPa above average for June across much of southern Australia; many sites with long-term MSLP data observed record high mean 9am MSLP for June, including all but one of the sites in South Australia, and all but three in Victoria." And the next few months are not looking that cheery for farmers, with the BoM's latest Climate Outlook indicating that this southward shift in high pressure and dry conditions will continue through into early spring.
The incredibly dry June has pushed rainfall deficiencies in some areas towards droughty levels looking at the past four months' figures. The western coast and nearby inland areas of WA are worst affected, with much of the Gascoyne coast area as well as smaller areas in the Central West and South West sitting on their lowest rainfall on record for the March to June period.
In SA, deficiencies have worsened on the Eyre, Yorke and Fleurieu peninsulas, Kangaroo Island, the Mid North and around Adelaide. In VIC, an area from West Gippsland to NE VIC is very dry, while in TAS serious deficiencies exist in the west and south over a four-month period, while the record dry June in the northeastern half means that it is now catching up.
On a three-month timescale, from April to June, a broad band of serious to severe deficiency has opened up from central NT to SE QLD, and others exist in the NSW Central West and eastern Riverina.
| 
