Two major weather events recently

By Peter Nelson

During the last few days there were two major weather events affecting the Nation. The heavy to flood rains of a record nature occurred at Hobart and nearby centres in south east of Tasmania.

Across to Perth there was unseasonable warmth for this time of year. The temperature soared to 32.7 degrees on May 12th and this was the highest May temperature since 34.3 in 2002.

Hobart had a record daily fall of 129.2mm for May last Friday 11th May. It was the fourth wettest ever day in 177 years of records; the wetter days being 132 mm in 1960, 147mm in June 1954 and 156mm in September 1957.

Record daily rainfalls were recorded at Grove, 160mm, Huonville, 150mm, Kingston, 179mm and at Leslie vale, 226mm. The month's rainfall total currently at Hobart is 146mm and this is approaching the May 1958 record of 213.8mm.

Other very wet Mays at Hobart were in 1848, 1882, 1905,1923 and 1956. Three of these namely 1848, 1882 and 1923 had followed a marked dry period of the previous 12months at Hobart which also happened during most of the last 12 months.

I do not have detailed  records for 1848 except for Hobart, Melbourne,Adelaide and Sydney. I was fortunate to photo copy these out of an old BOM publication of 1935 back in 1975 for the period 1840 to 1860. 

In Melbourne the period May 1848 to January 1850 was extremely wet with major floods particularly in November 1849 when 310mm fell in the City and I recall reading 300 mm fell in one day in Brighton. Both 1882 and 1923 saw much above average rain for the rest of those years whilst 1923 alone saw much above average rainfall up to Autumn of 1924.

The recent cold snap which was associated with the record rainfalls in south east Tasmania has ended our long spell of warmer than normal days and there will be frosts for the next week or so. The complex low which deepened over Tasmania did bring Melbourne's wettest May day for six years but only light falls in our area, although 46 mm fell at Harrietville.

Unseasonably warm days in Perth quite often reaches our area in a few days but because of the recent cold snap and with passages of weak cold fronts during this week it appears we will miss out this time.

However warm days have returned to Perth yesterday (May 15) and we should enjoy mild to warm days during the fourth week of May. In both 1923 and 1962 Perth had a lengthy warm spell during May and this transported into our area near the end of May and early June. Actually June 1962 was warmer than May that year in our area .

It is difficult to interpret when the next significant rainfall event will arrive as the recent two major weather events have never before occurred at the same time . Present indications for rain is about May 24 and again in early June.