Tasmania in autumn 2012: warm with heavy rain

Autumn rainfall was above average in most areas, but especially in the northwest and parts of the south following heavy rain in March, April and May. Autumn temperatures were warmer than average across Tasmania, by up to one degree in most areas.

  • Record heavy rain in the east and northwest
  • Wettest autumn on record for Cape Grim
  • Warm autumn days and nights
  • Warmest autumn night on record for Launceston, Dover and Maydena

Monthly summaries have been prepared for March, April and May.

Wet, especially in the south and northwest

Autumn rainfall was above average across most of Tasmania, except on Flinders Island. In parts of the south and northwest rainfall was well above average following heavy rainfall events in March, April and May. Cape Grim recorded its wettest autumn on record whilst several other sites, mainly in the northwest and on King Island, recorded their wettest autumn for at least 20 years.

The most notable of these heavy rainfall events was on 25 May when a low pressure system moved down along the east cost of Tasmania, delivering around 50 to 100 mm of rain to eastern parts of the state. In the 24 hours to 9 am on the 26th, Nugent (103 mm), Launceston (47 mm) and Campbell Town (64 mm) all recorded their wettest autumn day on record. Rainfall rates were intense in the northeast with this event: St Helens Aerodrome recorded 67 mm in one hour, causing flash flooding. Rainfall of this intensity is only expected to occur less than once in 100 years in St Helens.

Earlier in May, a low pressure system lingering over Tasmania produced heavy rain in the northwest and southeast, notably on the 3rd. In the 24 hours to 9 am on the 4th, Naracoopa (89 mm) and City of Melbourne Bay (98 mm) on King Island recorded their wettest autumn day on record.

Thunderstorms in the far south early on 24 April brought exceptionally heavy rain to Maatsuyker Island with 67 mm falling in just 90 minutes at the lighthouse. The overall daily total of 111 mm at Maatsuyker Island Garden was the highest daily rainfall total in Tasmania this autumn.

Mount Read was the wettest location with at least 1092 mm (though it is likely that snow was lost on some days through autumn, so this total should be higher). Lake Margaret Power Station was the next wettest site with 789 mm, whilst Avoca in the northeast was the driest with 114 mm for autumn.

Warm autumn days

Autumn days were up to 1 °C warmer than average across most areas of Tasmania, but just below average in parts of the Derwent Valley, Central Plateau and West Coast districts. This is in contrast to last autumn when maximum temperatures were below average statewide.

The warmest periods of autumn were the first week of April, when several sites across the state observed their warmest start to the month on record; and 13 to 21 March. Most sites recorded their warmest day of the season on either the 14 or 19 March if not within the first week of April. Strahan Aerodrome recorded the warmest day of autumn with 30.3 °C on 14 March.

There were a few cold periods – the coldest of which were around 23 March, 9 April and 12 May when snow fell down to at least 700 m. 23 March was a very cold day for so early in the season: temperatures generally remained below 15 °C and several sites recorded their coldest March day on record. Mt Read's maximum temperature of 0 °C was Tasmania's second lowest March maximum temperature on record. The coldest day of the season was on 12 May, when the temperature only reached -1.8 °C at Mount Wellington.

Warm autumn nights, record warm for some

There were many warmer than average nights in March, April and May, and few very cold nights. Overall autumn average minimum temperatures were warmer than normal as a result, by up to two degrees in the Derwent Valley, Central Plateau and Southeast districts, and up to one degree elsewhere. Strathgordon Village, Tarraleah Village and Geeveston all had their highest autumn mean daily minimum temperature on record.

The warmest periods were around 15, 16 and 21 March, and 20 April when warm northerly winds and cloudy conditions prevented much cooling. The night of 21 March was especially warm with Launceston (19.0 °C), Dover (17.8 °C) and Maydena (16.4 °C) all recording their warmest autumn night (highest daily minimum temperature) on record. Almost a week beforehand, Flinders Island observed the warmest night of the season when the temperature only fell to 19.7 °C on 15 March.

The coldest autumn nights were around 10 April, at the end of April and during May under clear skies and in the cold air behind cold fronts. The lowest temperature recorded for the season was -4.3 °C at Ross on 30 April following the passage of a vigorous cold front on the 28th. It is more common for the coldest autumn nights to occur in May in the lead-up to winter, but this year there were few very cold nights in May; the coldest was -4.0 °C at Fingal on the 29th. Last autumn the temperature dropped below -5 °C on several occasions, most of those at Liawenee in May.

A warm autumn for Hobart, with a wet finish

There was a distinct lack of cold nights in Hobart this autumn. In an average autumn the temperature falls to 5 °C or below on 11 days, 8 of which are in May. This year the lowest temperature was 4.0 °C on 30 April, and this was the only morning the temperature fell to 5 °C or below. Most nights were on the warm side of average, with the highest minimum of 18.3 °C on 21 March.

Autumn days were warmer than average too, but significantly warm in April when Hobart recorded its equal highest April mean maximum temperature on record. The first 6 days of April were very warm with an average maximum temperature of 24.5 °C, six degrees above the April average. There were a few cold autumn days, with most of those in May. A typical Hobart autumn has 8 days with a maximum of 12 °C or less, whilst this autumn there were only 4, the coldest of which was 10.7 °C on 12 May.

Both maximum and minimum temperatures were just over a degree above average overall – warmer than autumn last year, but cooler than the autumn of 2010 which was the warmest on record for Hobart.

Hobart received 145 mm of rainfall this autumn, which is just above the long-term average of 143 mm. 92 mm of this rain fell in May, which is double the long-term May average, and Hobart's wettest May since 1986. The wet conditions in May followed below average rainfall in March, and well below average rainfall in April.

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Extremes in autumn 2012
Hottest day 30.3 °C at Strahan Aerodrome on 14 Mar
Warmest days on average19.2 °C at Campania (Kincora), Eddystone Point
and Launceston (Ti Tree Bend)
Coolest days on average8.5 °C at Mount Wellington
Coldest day -1.8 °C at Mount Wellington on 12 May
Coldest night-4.3 °C at Ross (The Boulevards) on 30 Apr
Coolest nights on average 2.5 °C at Mount Wellington
Warmest nights on average12.7 °C at Swan Island
Warmest night 19.7 °C at Flinders Island Airport on 15 Mar
Warmest on average overall 15.5 °C at Swan Island
Coolest on average overall5.5 °C at Mount Wellington
Wettest overall1091.6 mm at Mount Read*
Driest overall 114.2 mm at Avoca (Railway House)
Wettest day110.8 mm at Maatsuyker Island Garden on 24 Apr
Highest wind gust150 km/h at Hogan Island on 7 Apr

* It is likely some snow was blown away at Mount Read, hence the autumn rainfall total should be higher.


Maps
ObservedAnomalyDecile rank
Total
rainfall
Map of Rainfall totals Map of Percentage of normal rainfall Map of Rainfall deciles
Mean
daily
maximum
temperatures
Map of Mean maximum temperature Map of Anomaly in mean maximum temperature Map of Decile rank of mean maximum temperature
Mean
daily
minimum
temperatures
Map of Mean minimum temperature Map of Anomaly in mean minimum temperature Map of Decile rank of mean minimum temperature

Click on a map to show it full size in a pop-up window


Record highest autumn daily rainfall
Highest daily rainfall
in autumn 2012 (mm)
Previous wettest
for autumn
Years of
record
Naracoopa 88.8 on 4 May 82.3 on 5 Apr 1929 94
City of Melbourne Bay 97.6 on 4 May 66.8 on 22 Mar 1978 77
Launceston (Ti Tree Bend) 47.2 on 26 May 42.0 on 7 Apr 1992 33
Nugent (Twilight Valley) 102.8 on 26 May 80.6 on 13 Apr 2011 29
Campbell Town (Elizabeth R) 63.6 on 26 May 43.7 on 3 May 1973 26



Record highest total autumn rainfall
Total rainfall
for autumn 2012 (mm)
Previous wettest
for autumn
Years of
record
Average for
autumn
Cape Grim BAPS (Comparison) 353.4 287.0 in 1987 25 191.0

Highest total autumn rainfall for at least 20 years
Total rainfall
for autumn 2012 (mm)
Most recent autumn
at least this wet
Years since
wetter
Average for
autumn
Naracoopa 402.4 407.8 in 1952* 58 232.2
City of Melbourne Bay 397.0 426.8 in 1973 39 244.5
Marrawah 384.8 476.3 in 1975 37 256.4
Maatsuyker Island Lighthouse 457.8 487.8 in 1982 30 309.0
York Plains (Handroyd) 172.2 198.2 in 1986 26 132.2
Wynyard Airport 275.4 351.5 in 1965* 22 218.5
Yolla (Sea View) 407.6 552.8 in 1989* 21 327.0
Barrington Post Office 313.6 395.8 in 1992 20 249.9
Burnie (Round Hill) 290.3 324.7 in 1992 20 218.4
Forthside Research Station 267.4 346.8 in 1992 20 215.3

* note: there are gaps in the historical record at this site, so it is possible a higher value has gone unreported.




Record highest autumn daily minimum temperature
Highest daily minimum
temperature
in autumn 2012 (°C)
Previous warmest
for autumn
Years of
record
Average for
autumn
Launceston (Ti Tree Bend) 19.0 on 21 Mar 18.5 on 4 Mar 1992 31 7.5
Dover 17.8 on 21 Mar 17.2 on 26 Mar 2010 23 7.3
Maydena Post Office 16.4 on 21 Mar 16.0 on 2 Mar 2007 20 5.5



Record highest autumn mean daily minimum temperature
Mean daily minimum
temperature
for autumn 2012 (°C)
Previous warmest
for autumn
Years of
record
Average for
autumn
Strathgordon Village 7.8 7.7 in 1980 29 7.0
Tarraleah Village 5.7 5.0 in 1989 27 4.1
Geeveston (Cemetery Road) 7.8 7.7 in 2007 24 6.4

Highest autumn mean daily minimum temperature for at least 20 years
Mean daily minimum
temperature
for autumn 2012 (°C)
Most recent autumn
at least this warm
Years since
warmer
Average for
autumn
Bushy Park (Bushy Park Estates) 6.9 7.5 in 1988 24 6.2

* note: there are gaps in the historical record at this site, so it is possible a higher value has gone unreported.




Summary statistics for autumn 2012
Maximum temperatures
for autumn
(°C)
Minimum temperatures
for autumn
(°C)
Rainfall
for autumn
(millimetres)
Mean for
autumn
2012
Diff
from
average
Highest for
autumn
2012
Mean for
autumn
2012
Diff
from
average
Lowest for
autumn
2012
Total for
autumn
2012
Average
for
autumn
Rank of
autumn
2012
Fraction of
autumn
average
Northern (district 91)
Bridport (Sea View Villas) 18.5 +0.2 27.2 14 Mar 9.8 +0.2 1.8 13 May 217.7 169.0 high 129%
Burnie (Round Hill) 18.6 +0.9 25.2 14 Mar 10.6 +0.5 3.8 10 Apr 290.3 218.4 high 133%
Cape Grim 16.4   22.6 20 Mar 11.8   6.4 4 May 339.8
Cape Grim BAPS (Comparison) 16.8 +0.3 22.7 20 Mar 11.7 +0.2 6.5 3 May 353.4 191.0 highest 185%
Cressy Research Station 18.5 -0.1 29.0 14 Mar 6.2 +0.5 -2.5 20 May
Devonport Airport 18.3 +0.6 25.9 14 Mar 8.8 +0.1 1.0 29 May 185.3 181.5 average 102%
Launceston (Ti Tree Bend) 19.2 +0.2 30.0 14 Mar 7.8 +0.3 -0.4 20 May 173.9 152.5 average 114%
Launceston Airport 18.6   29.8 14 Mar 6.7   -2.4 29 May 190.6
Low Head 18.0 +0.4 25.4 14 Mar 11.5 +0.3 4.5 29 May 210.2 159.1 high 132%
Luncheon Hill (Forestry) 15.6 -0.2 26.0 14 Mar 8.5 +0.3 2.6 10 Apr 406.0 342.4 high 119%
Marrawah 17.0 +0.1 24.5 14 Mar 10.9 +0.6 5.5 23 Mar 384.8 256.4 v high 150%
Scottsdale (West Minstone Road) 17.7 -0.3 28.0 14 Mar 7.8 -0.1 -0.8 24 Mar 245.6 232.0 average 106%
Sheffield School Farm 16.7 +0.1 25.7 14 Mar 7.0 -0.2 0.0 10 Apr 342.2 212.2 v high 161%
Smithton Aerodrome 17.8 0.0 24.4 14 Mar 8.1 +0.3 0.8 4 May 285.0 186.5 v high 153%
Wynyard Airport 18.1 +0.6 24.5 14 Mar 7.9 +0.6 0.2 10 Apr 275.4 218.5 high 126%
East Coast (district 92)
Bicheno (Council Depot) 18.8 +0.2 26.8 4 Mar 10.6 +0.4 4.5 30 Apr 201.7 174.0 high 116%
Eddystone Point 19.2 +1.1 25.9 31 Mar 11.5 0.0 3.4 24 Mar
Fingal (Legge Street) 18.6 +0.3 29.3 14 Mar 5.4 0.0 -4.0 29 May 129.4 147.0 average 88%
Friendly Beaches 18.9 +0.2 28.4 31 Mar 10.3 +0.4 2.4 30 Apr 321.4 173.6 high 185%
Lake Leake (Elizabeth River) 14.4 +0.1 22.9 5 Apr 4.8 +0.7 -3.0 30 Apr 210.0 205.0 average 102%
Maria Island (Point Lesueur) 18.1   25.1 5 Apr 11.6   5.8 10 Apr 221.4
Orford (Aubin Court) 18.6 +0.4 28.4 21 Mar 8.7 +0.3 1.2 29 May 245.0 163.8 high 150%
Scamander 18.7 0.0 26.6 4 Apr 9.5 -0.2 3.0 12 May 250.1 191.5 high 131%
St Helens Aerodrome 18.7 +0.3 25.4 3 Apr 9.5 +0.1 1.7 13 May 293.4 172.1 high 170%
Swan Island 18.3 +0.2 24.7 20 Mar 12.7 +0.1 5.2 14 May 149.8 155.7 average 96%
Swansea (Francis Street) 18.9   28.4 31 Mar 8.8   1.0 30 Apr 189.6
Midlands (district 93)
Ross (The Boulevards) 18.0 +0.2 29.5 14 Mar 6.1 +0.5 -4.3 30 Apr 167.2 101.1 v high 165%
Southeast (district 94)
Bull Bay (Lauriston) 17.6 +0.3 25.5 31 Mar 10.3 +0.7 4.3 24 Mar 195.2 133.2 high 147%
Campania (Kincora) 19.2 +0.3 28.3 6 Apr 8.0 +0.4 -0.6 30 Apr 149.0 105.8 high 141%
Cape Bruny (Cape Bruny) 16.8 +0.4 25.2 20 Mar 10.6 +0.6 3.6 24 Mar 288.6 172.2 v high 168%
Cape Bruny Lighthouse 16.4 +0.9 24.2 20 Mar 10.8 +1.1 2.9 24 Mar 300.6 232.3 high 129%
Dover 17.1 +0.3 25.6 20 Mar 8.1 +0.8 1.0 30 Apr 262.4 203.0 high 129%
Geeveston (Cemetery Road) 17.1 -0.2 26.8 19 Mar 7.8 +1.4 -0.4 30 Apr 290.8 194.0 high 150%
Grove (Research Station) 17.9   27.2 19 Mar 6.3   -1.8 30 Apr 218.7
Hobart (Ellerslie Road) 18.6 +1.3 28.9 5 Apr 10.2 +1.3 4.0 30 Apr 145.0 142.9 average 101%
Hobart Airport 18.8 +0.8 28.1 20 Mar 9.2 +0.5 2.5 30 Apr 140.8 114.9 high 123%
Maatsuyker Island Lighthouse 14.9 +0.4 24.3 19 Apr 10.4 +0.9 4.8 13 May 457.8 309.0 v high 148%
Melton Mowbray (North Stockman) 17.4 -0.1 27.2 14 Mar 7.0 +0.9 0.4 30 Apr 138.4 92.0 high 150%
Mount Wellington 8.5 +0.1 18.0 5 Apr 2.5 +0.3 -3.6 13 May
Tasman Island 15.2 +0.3 23.9 5 Apr 10.2 +0.4 3.1 13 May 339.0 214.5 v high 158%
Tunnack Fire Station 15.7 +0.2 26.1 14 Mar 6.0 +0.6 -3.2 30 Apr
Derwent Valley (district 95)
Bushy Park (Bushy Park Estates) 18.7 +0.7 28.3 19 Mar 6.9 +0.7 -0.8 30 Apr 166.4 131.1 high 127%
Maydena Post Office 15.8 -0.3 27.6 14 Mar 6.9 +1.4 1.5 10 Apr 321.2 248.0 high 130%
Ouse Fire Station 18.4 -0.1 29.4 14 Mar 6.7 +1.3 -0.6 30 Apr
Tarraleah Village 13.5 -0.7 25.2 14 Mar 5.7 +1.6 -1.2 29 May 359.5 268.8 high 134%
Central Plateau (district 96)
Butlers Gorge 13.0 -0.2 25.2 14 Mar 4.9 +1.5 -1.8 2 Apr 428.8 404.8 average 106%
Lake St Clair National Park 12.8 -0.5 25.2 14 Mar 4.3 +1.4 -3.1 29 May 491.0 401.3 high 122%
Liawenee 11.6 -0.9 22.1 14 Mar 2.7 +1.0 -4.2 30 Apr 289.4 211.9 high 137%
West Coast (district 97)
Cape Sorell 16.9 +1.4 27.8 14 Mar 11.4 +1.1 6.3 24 May 352.0 322.3 average 109%
Hartz Mountain (Keoghs Pimple) 10.8 -0.7 21.2 14 Mar 5.0 +0.3 -1.1 13 May
Mount Read 8.6 -0.4 21.6 14 Mar 3.6 +0.2 -1.9 9 Apr 1091.6* 949.1 average 115%
Scotts Peak Dam 14.8 0.0 26.1 19 Mar 7.5 +0.7 1.2 13 May 580.6 398.1 v high 146%
Strahan Aerodrome 17.1 +0.4 30.3 14 Mar 9.3 +0.8 2.5 4 May 447.0 358.6 high 125%
Strathgordon Village 14.2 -0.1 23.2 19 Mar 7.8 +0.8 2.0 9 Apr 658.0 590.4 average 111%
Warra 13.5   22.9 19 Mar 6.3   0.6 13 May 471.0
King Island (district 98)
King Island Airport 18.0 +0.3 28.4 14 Mar 11.3 +0.8 5.9 16 Apr 258.0 193.3 high 133%
Flinders Island (district 99)
Flinders Island Airport 18.7 0.0 29.3 14 Mar 11.3 +0.6 1.2 14 May 132.7 188.0 low 71%
Antarctica and Macquarie Island (district 300)
Macquarie Island 7.4 +0.5 10.1 16 Mar 4.1 +0.5 -1.8 30 Apr 279.8 276.1 average 101%

* It is likely some snow was blown away at Mount Read, hence the autumn rainfall total should be higher.


Notes

A Seasonal Climate Summary is prepared to list the main features of the weather in Tasmania using the most timely and accurate information available on the date of publication; it will generally not be updated. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review, usually published in the fourth week of the month.

This statement has been prepared based on information available at 9 am on Friday 1 June 2012. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

Averages are long-term means based on observations from all available years of record, which vary widely from site to site. They are not shown for sites with less than 10 years of record, as they cannot then be calculated reliably.
The median is sometimes more representative than the mean of long-term average rain.

The Rank indicates how rainfall this time compares with the climate record for the site, based on the decile ranking (very low rainfall is in decile 1, low in decile 2 or 3, average in decile 4 to 7, high in decile 8 or 9 and very high is in decile 10).
The Fraction of average shows how much rain has fallen this time as a percentage of the long-term mean.

Further information

Media
(03) 9669 4057
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