Continued heavy rain events again last week has resulted in floods at many places in our regions. Many farms are now completely waterlogged particularly in NE Victoria and the Riverina. The worst floods to date have been around Forbes which has had it's wettest September since 1996 and also the wettest May to September period in any year since 1892. The May to September periods at Forbes were also very wet in 1917, 1956, 1973 and 1978.
The latest rain event of last Wednesday, 21st September saw the wettest ever September day at Meningee in 140 years of records when 63 mms fell and this month's total is close to the record wet September of 134 mms in 1916. Many other places have now surpassed their annual averages. The state of SA shows nearly every station has now passed their annual average.
During last week an out of season deluge occurred at Jabiru in the Top End of the NT when 232 mms fell. September in Jabiru is usually the driest month of the year with only 15 mms rainfall. and past records dating back to 1971 showed the closest deluge of that magnitude at that time of year was 270 mms in October 2010 of which 161 mms fell on the 10th.. After that October 2010 deluge there were major floods in our regions from November to January.
Out in the Indian Ocean Christmas Island was swamped by record September rains the last 4 days when 227 mms fell. . The month's total this month at Christmas Island has reached 393 mms breaking the previous September record of 1975 when 346 mms fell. September is normally the driest month of the year at Christmas Island and also at nearby Cocos Island which is having it's wettest September since 2001. Other Septembers with high rainfalls at Christmas Island were in 1906, 1909, 1958 and 1978.
The current prognosis synoptic charts for the coming week indicate a deepening low pressure to hit our regions this Thursday once again. This year has seen an absence of very strong high pressure systems from April onwards. . Last year there were many cases of very high barometer readings From April right through to December in our regions.