Tasmania in winter 2011: Wet with flooding in the northeast

Two heavy flooding rain events in August meant it was a wet winter in the northeast of Tasmania.
Night time and daytime temperatures were warmer than average this winter, following a very warm August. There were however, a few very cold nights, mostly in July.

  • Wet with flooding in the northeast in August
  • Warm winter days and nights
  • Strong winds and large waves in June and July
  • A record low -11.2 °C for Liawenee
Monthly summaries have also been prepared for June, July and August.

A wet winter in the northeast

The northeast received well above average rainfall due to wet conditions in June and August . Winter rainfall totals in the northeast generally ranged from 200 mm to 300 mm, increasing up to 900 mm at Mount Victoria (not far behind the usually wet Strathgordon in the southwest with 919 mm). Fingal recorded its wettest winter in 20 years with 347 mm following its wettest August on record. In contrast, the driest winter site was Maria Island off the southeast coast, where 104 mm was recorded.

Winter rainfall was generally close to average across the rest of Tasmania. Cold fronts delivered most of the state’s rainfall, along with the passage of low pressure systems across Bass Strait delivering rainfall to the north and east of Tasmania in July and August. In the south, Richmond and Huonville had their wettest winter days on record on 8 and 9 June respectively associated with the passage of a low pressure system and cold front.

Flooding in the northeast

There were two significant flooding events in the northeast this winter associated with complex areas of low pressure to the north of Tasmania. Both events were in August and within a week of each other, causing hundreds of thousands of dollars worth of damage to infrastructure.

Warm winter nights with a few very cold ones

Average minimum temperatures were up to 2 °C warmer than normal for winter, due largely to very warm nights in August when several sites across Tasmania had their warmest August minimum temperatures on record. Nights were warm at the end of July too, with Bushy Park, Butlers Gorge, Tarraleah Village and Strahan all recording their warmest July nights on record on the 29th.

There were some very cold nights this winter however, most of those in July. Of particular note was the 23rd of July when Liawenee recorded its coldest temperature ever with -11.2 °C. The mix of a mild August and a cold July ensured that no other winter temperature records were set.

A very warm end to winter

Daytime temperatures were close to the winter average overall, but generally on the warm side. The coldest days were in July. Many areas were on track to record their coldest July in several years until a warm spell developed at the end of the month. This warmth generally persisted for the rest of winter. For most areas, their warmest winter days were either at the start or the end of August.

Bicheno was the warmest winter location, recording an average winter maximum of 14.7 °C, whilst Mount Wellington, as usual, had the coolest days with a mean winter maximum of 4.0 °C.

Wild weather

In addition to the two flooding events in August, there were two other significant weather events in winter. Strong winds, large waves, and low level snow affected Tasmania in the first week of June, and again in the first week of July. Winds were especially damaging in the July event, and the waverider buoy off Cape Sorell recorded an exceptionally large 18.68 m wave.

Hobart: a warm winter with average rainfall

Temperatures were warmer than normal overall and rainfall was close to average in Hobart this winter. Both the average maximum (13.3°C) and the average minimum (5.9 °C) temperatures were close to one degree warmer than the long-term winter average. Daytime temperatures were below average for most of July, when Hobart was on track to record its coolest July in 16 years, but temperatures rose at the end of the month and remained warmer than average for most of winter. Hobart had 25 winter days were the maximum temperature was 15 °C or higher, compared to the average of 14 days. The warmest day was on 24 August where the temperature rose to 22 °C, which was the warmest winter day since 30 August 2006.

Hobart did have some cold winter nights. On 16 June the temperature dipped to 0.8 °C, and every night from 23 July to 27 July it dropped below 2 °C, and right down to 0.6 °C on both 25 and 27 July. In contrast, it stayed above 11 °C from 17 to 21 August.

The 168 mm of rain that Hobart received this winter was very close to average, and slightly more than the 124 mm received last winter. There was 43 mm of rain over two days early in June, ensuring it was the wettest of the months this winter.

Further information

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Extremes in winter 2011
Hottest day 22.2 °C at Flinders Island Airport on 4 Aug and 5 Aug
Warmest days on average 14.7 °C at Bicheno (Council Depot)
Coolest days on average 4.0 °C at Mount Wellington
Coldest day -2.9 °C at Mount Wellington on 10 Jul
Coldest night -11.2 °C at Liawenee on 23 Jul
Coolest nights on average -0.9 °C at Liawenee
Warmest nights on average 9.2 °C at Hogan Island
Warmest night 13.7 °C at Cape Sorell on 25 Aug
Warmest on average overall 11.4 °C at Hogan Island
Coolest on average overall 1.7 °C at Mount Wellington
Wettest overall 918.8 mm at Strathgordon Village
Driest overall 103.4 mm at Maria Island (Point Lesueur)
Wettest day 141.4 mm at Mount Victoria (Una Plain) on 9 Aug
Highest wind gust 178 km/h at Mount Wellington on 10 Jul


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 winter daily rainfall

Highest daily rainfall
in winter 2011 (mm)
Previous wettest
for winter
Years of
record
Huonville (Tutton Avenue) 76.0 on 9 Jun 62.0 on 26 Jun 2009 42
Richmond (Strathayr) 53.8 on 8 Jun 46.4 on 12 Aug 2010 24



Highest total winter rainfall for at least 20 years

Total rainfall
for winter 2011 (mm)
Most recent winter
at least this wet
Years since
wetter
Average for
winter
Fingal (Legge Street) 346.6 404.4 in 1981 30 174.9




Summary statistics for winter 2011
Maximum temperatures
for winter
(°C)
Minimum temperatures
for winter
(°C)
Rainfall
for winter
(millimetres)
Mean for
winter
2011
Diff
from
average
Highest for
winter
2011
Mean for
winter
2011
Diff
from
average
Lowest for
winter
2011
Total for
winter
2011
Average
for
winter
Rank of
winter
2011
Fraction of
winter
average
Northern (district 91)
Bridport (Sea View Villas) 13.7 0.0 16.7 18 Jul 5.7 -0.1 0.0 7 Jul 195.0 248.6 average 78%
Burnie (Round Hill) 13.7 +0.6 17.5 11 Jun 7.5 +1.3 1.3 13 Jun 307.4 338.0 average 91%
Cape Grim 12.7   15.6 19 Aug 8.5   2.8 15 Jun 310.4
Cape Grim BAPS (Comparison) 12.8 +0.1 16.2 22 Aug 8.4 0.0 3.3 15 Jun
Cressy Research Station 12.4 0.0 18.4 19 Aug 3.3 +1.5 -4.3 15 Jul 197.6 196.4 average 101%
Devonport Airport 13.3 +0.3 17.3 19 Aug 5.7 +0.8 -1.7 27 Jul 220.7 264.7 low 83%
Launceston (Ti Tree Bend) 13.6 +0.5 18.5 19 Aug 4.2 +1.3 -2.6 15 Jul 240.9 231.4 average 104%
Launceston Airport 12.3   17.8 19 Aug 3.5   -3.7 16 Jul 224.6
Low Head 13.0 -0.1 15.9 19 Aug 7.8 +0.6 1.0 27 Jul 179.4 224.2 low 80%
Luncheon Hill (Forestry) 11.2 +0.2 17.5 22 Aug 5.5 +0.3 0.5 21 Jul 567.4 545.1 average 104%
Marrawah 13.0 +0.4 17.5 22 Aug 7.7 +0.7 1.5 15 Jun 352.6 392.1 average 90%
Scottsdale (West Minstone Road) 12.5 +0.1 16.9 19 Aug 4.7 +0.8 -2.1 14 Jul 272.8 344.1 low 79%
Sheffield School Farm 11.5 +0.1 15.2 24 Jun 4.2 +0.5 -1.8 11 Aug 314.4 364.8 low 86%
Smithton Aerodrome 13.5 0.0 17.1 24 Aug 5.4 +0.5 -2.3 20 Jul
Wynyard Airport 13.5 +0.4 16.8 9 Aug 4.6 +0.8 -2.5 14 Jul 366.0 355.5 average 103%
East Coast (district 92)
Bicheno (Council Depot) 14.7 +0.3 22.0 4 Aug 6.7 +0.4 0.7 6 Jul 181.6 164.9 average 110%
Eddystone Point 14.3 +0.8 18.7 24 Aug 8.0 +0.6 1.2 14 Jul 204.2 223.6 average 91%
Fingal (Legge Street) 12.9 +0.2 19.8 4 Aug 2.0 +1.1 -5.4 27 Jul 346.6 181.0 v high 191%
Friendly Beaches 14.0 -0.2 21.4 4 Aug 6.4 +0.3 -0.6 16 Jul 209.2 153.1 high 137%
Lake Leake (Elizabeth River) 9.1 +0.1 14.4 1 Jun 1.5 +1.0 -6.3 16 Jul 345.2 243.5 high 142%
Maria Island (Point Lesueur) 13.0   18.8 4 Aug 8.0   3.5 11 Jul 103.4
Orford (Aubin Court) 13.3 -0.2 19.4 4 Aug 4.3 +0.4 -2.8 16 Jul 162.0 172.5 average 94%
Scamander 14.3 0.0 21.5 4 Aug 5.8 +0.7 -1.2 6 Jul 286.3 176.1 high 163%
St Helens Aerodrome 13.9 0.0 19.9 4 Aug 5.8 +0.6 -0.1 15 Jul 275.0 179.8 high 153%
Swan Island 13.6   18.0 2 Jun 9.0   4.0 15 Jul 223.8
Midlands (district 93)
Ross (The Boulevards) 12.0 +0.2 18.6 19 Aug 2.6 +0.8 -6.5 27 Jul 157.6 129.4 average 122%
Southeast (district 94)
Bull Bay (Lauriston) 12.8 0.0 20.0 24 Aug 6.3 +0.3 1.5 25 Jul 158.6 159.7 average 99%
Campania (Kincora) 13.8 +0.1 21.3 24 Aug 4.2 +0.6 -2.2 25 Jul
Cape Bruny (Cape Bruny) 12.4 0.0 19.8 25 Aug 6.8 0.0 2.2 23 Jul 228.4 239.7 average 95%
Dover 12.8 +0.1 20.2 25 Aug 4.4 +0.6 -1.8 25 Jul 315.4 255.1 high 124%
Geeveston (Cemetery Road) 12.7 +0.2 20.1 25 Aug 3.5 +1.1 -2.9 24 Jul 399.8 269.1 v high 149%
Grove (Research Station) 12.9   21.0 24 Aug 2.9   -4.7 27 Jul 280.0
Hobart (Ellerslie Road) 13.3 +1.1 21.7 24 Aug 5.9 +0.9 0.6 25 Jul 167.8 159.9 average 105%
Hobart Airport 13.5 +0.6 21.4 24 Aug 5.4 +1.0 -1.1 15 Jul 151.2 122.4 high 124%
Maatsuyker Island Lighthouse 11.6 +0.4 16.8 16 Aug 7.7 +0.9 1.3 11 Jul 284.5 370.0 low 77%
Melton Mowbray (North Stockman) 11.9 -0.1 19.4 24 Aug 2.7 +0.5 -5.1 16 Jun 166.2 117.9 high 141%
Mount Wellington 4.0 +1.2 10.8 19 Aug -0.6 +0.8 -6.0 7 Jul
Tasman Island 11.1   17.6 4 Aug 6.9   1.4 7 Jul 220.8
Tunnack Fire Station 10.0 0.0 15.8 19 Aug 2.5 +0.5 -5.6 24 Jul 354.0 177.7 v high 199%
Derwent Valley (district 95)
Bushy Park (Bushy Park Estates) 12.8 +1.0 21.5 24 Aug 2.5 +0.6 -4.9 25 Jul 212.0 151.6 high 140%
Maydena Post Office 11.3 +0.2 19.0 25 Aug 2.9 +0.5 -3.5 24 Jul 484.1 362.6 high 134%
Ouse Fire Station 12.4 0.0 20.8 24 Aug 2.1 +0.6 -5.0 23 Jul 170.8 162.7 average 105%
Tarraleah Village 9.3 +0.5 16.5 24 Aug     -6.0 23 Jul 423.3 344.5 high 123%
Central Plateau (district 96)
Butlers Gorge 8.8 +1.3 16.7 19 Aug 0.7 +0.8 -6.3 16 Jul 641.2 512.2 high 125%
Lake St Clair National Park 8.1 +0.4 16.2 20 Aug 0.6 +0.5 -5.9 15 Jun 737.4 624.8 high 118%
Liawenee 6.7 +0.5 14.2 19 Aug -0.9 +0.3 -11.2 23 Jul
West Coast (district 97)
Cape Sorell 13.1 +1.1 17.2 21 Aug 8.3 +1.0 2.8 24 Jul
Hartz Mountain (Keoghs Pimple) 7.0 +0.5 14.9 19 Aug 2.0 +0.3 -3.2 7 Jul
Mount Read 4.7 +0.6 11.2 19 Aug 0.7 +0.3 -3.7 6 Jul
Scotts Peak Dam 10.3 +0.6 20.4 19 Aug 3.9 +0.4 -2.3 24 Jul
Strahan Aerodrome 13.1 +0.5 18.4 16 Aug 6.1 +0.7 -2.1 24 Jul 476.8 498.3 average 96%
Strathgordon Village 10.2 +0.7 16.2 23 Aug 4.0 +0.6 -1.8 24 Jul 918.8 779.7 high 118%
Warra 9.5   17.0 25 Aug     -3.0 23 Jul
King Island (district 98)
King Island Airport 13.9 +0.3 18.4 3 Aug 8.3 +0.6 1.9 15 Jun 272.4 327.8 low 83%
Flinders Island (district 99)
Flinders Island Airport 14.4 +0.7 22.2 5 Aug 7.2 +0.6 -1.5 15 Jul 156.5 230.4 low 68%
Hogan Island 13.6   20.3 4 Aug 9.2   4.9 8 Jun 225.4
Antarctica and Macquarie Island (district 300)
Macquarie Island 4.8 -0.2 8.1 22 Jun 1.3 -0.3 -6.5 24 Jul 250.8 222.1 high 113%

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 11 am on 1 September 2011. 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 the years 1895 to 2100. They are not shown for sites with less than 10 years of record in that time, 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
Enquiries