Wednesday, 1 June 2011 - Monthly Climate Summary for Tasmania - Product code IDCKGC27R0

Tasmania in May 2011: less rain, lower temperatures

May 2011 was the first month this year without extremely heavy rainfall. The state was mostly drier than usual though cold fronts brought some rain and snow on several days. It was cool overall following many cold and frosty nights and cool days.

• Cold outbreak with snow and large waves
• Launceston's coldest May day on record
• Drier than usual

Extremes Maps Records Summaries Important notes the top

End to the wet

Cold fronts brought rain to Tasmania on several days during May but it was still drier than usual overall. It was the first month of 2011 without extremely heavy rain, the highest daily total being just 38.6 mm at Lake St Clair on the 14th. Memana (22.6 mm) on Flinders Island had its driest May on record and less than 25 mm fell through much of the East Coast and in the Derwent Valley, with only 9.6 mm recorded at Ouse. In the west totals reached 338 mm at Mount Read, but even this was below average.

The Midlands was one area that had near normal rainfall, after falls of around 10 mm on the 1st and 23rd. The far southeast around Bruny Island and the Tasman Peninsula were slightly wetter than usual with Premaydena (103 mm) having its wettest May since 1985.

Launceston's coldest May day on record

A cloudy day and cold airmass gave Launceston its coldest May day on record on the 12th, with a maximum of just 9.6 °C (beating the previous record of 9.8 °C set on 21 May 1982). This occurred during a period of cold weather from the 8th to the 14th when fronts brought showery conditions and mountain snow. Bicheno (12.1 °C) and Strahan (9.2 °C) had colder days than the whole of 2010, and Scottsdale (9.6 °C) and Ross (7.6 °C) had their coldest May day in over 15 years. Mount Wellington reached only -0.3 °C on the 8th.

Days were warm between the 19th and 23rd (Bushy Park reached 22.8 °C on the 22nd) but generally cool during the rest of the month. Average maximum temperatures were around half to one degree cooler than usual in most areas. Orford had its lowest May mean daily maximum temperature on record. Only a few sites in the Derwent Valley were warmer than usual.

Many cold and frosty nights

Cold and frosty nights were common during May, especially from the 5th to 15th and again from the 25th to 30th. The coldest temperatures were in the north, with Liawenee falling to -7.4 °C on the 10th and -7.0 °C on the 28th. Smithton recorded its coldest temperature since 1997 (-2.9 °C on the 10th) and Devonport had its coldest May morning since 1994 (-0.5 °C on the 28th).

Nights were warm on the 1st and from the 16th to 23rd, but it was still cooler than usual overall. Average minimum temperatures were one to two degrees below normal in the north and within half a degree of normal in the south. Eddystone Point (8.2 °C) and Orford (4.4 °C) had their lowest May mean daily minimum temperature in over 20 years.

Huge swells in the south and west

Following a cold outbreak on the 8th, several low pressure systems passed to the distant south of Tasmania generating huge southwest swells that affected the west and south coasts. The waverider near Strahan recorded a peak height of 12.7 metres early on the 14th, while swells at Cape Bruny reached 5 metres. A second peak occurred around midday on the 17th, with swells reaching 7 metres at Cape Bruny. Such large swells are rare in the southeast, but still well short of the extreme 10 metres reported at Cape Bruny in September 2010.

Hobart: little rain and some cold weather

Showers fell in Hobart on several days, but totals were small and for the whole month the city received only half its average May rainfall. This made it the first month this year with below average rainfall. The wettest day was 6.8 mm (to 9 am on the 24th), and the monthly total was 23.6 mm (the long-term average is about 46 mm).

There were several cold days: temperatures struggled to reach 13 °C from the 8th to the 14th and peaked at just 10.4 °C on the 24th in a cold southerly airsteam. In contrast, most days between the 16th and 23rd exceeded 18 °C . Cold nights were also common, with the temperature falling below 4 °C six times (this hasn't happened since 1969). Overall, both days (14.9 °C) and nights (7.1 °C) were slightly warmer than usual.

Extremes Maps Records Summaries Important notes the top

Maps
	Observed	Anomaly	Decile rank
Total rainfall
Mean daily maximum temperatures
Mean daily minimum temperatures

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Extremes Maps Records Summaries Important notes the top

Extremes Maps Records Summaries Important notes the top