A deep low pressure which formed in the Bight last week and moved across Tasmania brought exceptional winds and severe thunderstorms at many places in our region. Tamworth recorded a wind gust of 139 kph during a thunderstorm and the heaviest December rainfall for 6 years with 51 mms. Aireys Inlet had a record wind gust of 109 kph last Thursday 8th December and nearly every place in Tasmania had very strong winds over 100 kph as the deep low of 980 mbs passed directly over this State.
The deep low brought an abrupt end to the very hot conditions in out back QLD and many thunderstorms were reported; Emerald reported 58 mms. Northern Tasmania had more heavy rain with Sheffield getting closer to the record wet year of 1917.
Deep low pressures have dominated the synoptic charts since early September and have also been frequent on these charts in May, June and July this year. In Melbourne barometric pressures the last 4 months have been low and similar occurrences were in 1863, 1893, 1948, 1952 and 1971. The summer following these past cases were not outstandingly hot, although January 1894 was slightly warmer than normal. So far there has not been a maximum temperature reaching 35 in Melbourne and looking at these past cases the temperature did not reach 35 before mid December. I do recall there was a lot of thunderstorms in the summers of 1948-49, 1952-53 and 1971-72 and this summer is likely to follow suit.