Friday, 29 June 2007

MEDIA RELEASE

Exceptional cold and rain in the tropics in June

If southerners heading north for warmer climes felt they’d been short-changed these past few weeks, the Bureau of Meteorology has confirmed their suspicions, with the Australian tropics experiencing one of the coldest June months on record. The Bureau’s National Climate Centre has also noted that the cold conditions experienced from 17 to 22 June were accompanied by widespread unseasonable rain during what is normally the dry season.

The cold snap resulted from the combination of an extensive and slow-moving middle-level cloud band associated with an upper-level trough. At the same time, there was a south-southeasterly surge over much of the tropics as a direct result of the circulation from the intense low-pressure system off the NSW coast, which brought the flood rain to that region.

Record low daily maximum temperatures were widespread through the tropics. The areas that were spared included the Cape York Peninsula, the Pilbara and the Queensland coast north of Townsville. In total, more than 31 per cent of the land area of Australia recorded lowest maximum temperatures for June.

The conditions have contributed to a new record for the wettest June in tropical Australia, with the area-averaged total of 46.9 millimetres (as of 27 June) exceeding the previous record of 39.1 mm set in both 1939 and 1973.

Blair Trewin of the National Climate Centre says the cold snap is very unusual. “In the past, most of the notable events of this kind have occurred during the warmer months of the year, often creating even larger observed differences between the recorded maximum temperatures and what would normally be expected at that time. To experience such low temperatures at this time of the year is pretty rare,” Blair says.

Further information:

Dr Blair Trewin, Climate Analysis, National Climate Centre, Bureau of Meteorology,
tel: (03) 9669 4623

Neil Plummer, Acting Superintendent, National Climate Centre, Bureau of Meteorology,
tel: (03) 9669 4714

The Special Climate Statement: http://www.bom.gov.au/climate/current/special-statements.shtml