Wednesday, 1 September 2010 - Monthly Climate Summary for Tasmania - Product code IDCKGC17R0

Tasmania in August 2010: Cold and wet with heavy rain and snow

In contrast to most months this year, August was wetter and cooler than usual. Constant heavy rain fell in eastern parts of the state between the 10th and 12th, leading to the wettest August on record for some areas. Snow was common, and several sites had their coldest month in over a year.

  • 199 mm in a day at Mount Wellington
  • Flooding in the northeast
  • Snow settling to 200 metres
A summary covering all of winter has also been prepared.

Extremes Maps Records Summaries Important notes the top


A deluge in the east

Record-breaking rain fell in eastern Tasmania between the 10th and 12th as a deep low pressure system passed near the northeast of the state. It was one of the wettest August days Tasmania has ever experienced, with 175 mm falling at Gray overnight on the 10-11th followed by 199 mm at Mount Wellington during the day. In 36 hours, many parts of the east and Derwent Valley had more rain than usually falls for the whole month and a number of sites had their wettest August day on record. The downpour was welcome in the southeast, which was experiencing one of its driest years on record, but not so welcome in the northeast, where it caused road closures and flooding of several rivers.

Wetter than usual overall

The deluge in the east from the 10th to 12th combined with moderate to heavy rain on several other days to ensure a wetter than usual August in most areas. Parts of the east had more than double the monthly average, and some sites, including Hobart, Mount Wellington and Nugent, had their wettest August in 20 or 30 years. Mount Read was the wettest overall with 356 mm, while Tunbridge with 28 mm was the driest site, having missed out on much of the heavy rainfall. The second driest location was Ross, with 46 mm. Only a few sites on the southwest coast were drier than usual.

Cold with plenty of snow

Winter hit with a vengeance in August after relatively mild daytime temperatures and little snow during either June or July. In contrast to most other months this year, average temperatures for August were around half a degree cooler than usual in most areas. There were several cold days when temperatures struggled to reach double digits, followed by almost as many cold nights. The coldest morning was the 7th, when Liawenee dropped to -6.9 °C. Highland snowfalls were frequent, especially in the second half on the month when falls settled to 200 metres on the 16-17th, 450 metres on the 19-20th and 400 metres on the 26-27th. A consequence was very cold days in mountainous areas: Mount Wellington didn't break the freezing point on 6 days (in July every day had been above 0 °C). The coldest day was -2.0 °C at Mount Wellington on the 16th.

A brief respite from the cold came between the 11th and 15th when a milder airmass moved over the state, bringing the warmest temperatures for the month. The warmest morning was the 11th, when cloud, rain and easterly winds kept temperatures mild and Eddystone Point didn't drop below 11.3 °C. A few days later on the 15th both Hobart and Bicheno climbed over 18 °C, making it the warmest day of the month.

Rain at last for Hobart

Hobart had its wettest August since 1978 after heavy rain on the 11th and moderate rain on a number of other days. The monthly total of 107.8 mm was more than double the average for this time of the year, and more than fell in the previous five months combined. Most of the rain fell on the 11th, with 58.8 mm recorded to 9 am on the 12th. This is the second-highest August daily rainfall on record for Hobart (the wettest was 64.8 mm on 2 August 1976). It was also the wettest day since January 2007. Despite this, Hobart's rainfall total for 2010 so far is only 249 mm, 36% less than the January-to-August average of 390 mm and much lower than the 529 mm recorded over the same period last year.

As well as rain there were several cold days in Hobart: the temperature only reached 9.4 °C, 9.5 °C and 9.8 °C on the 6th, 20th and 27th respectively. Nevertheless, the month as a whole was warmer than usual with an average maximum temperature of 13.8 °C (0.8 °C above average). The average overnight temperature of 5.3 °C was near average, with daily values ranging from 1.5 °C on the 8th to 9.3 °C on the 31st. 

Further information

Media
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Extremes in August 2010
Hottest day 18.4 °C at Hobart (Ellerslie Road) on the 15th
Warmest days on average 14.7 °C at Bicheno (Council Depot)
Coolest days on average 2.6 °C at Mount Wellington
Coldest day -2.0 °C at Mount Wellington on the 16th
Coldest night -6.9 °C at Liawenee on the 7th
Coolest nights on average -1.7 °C at Mount Wellington
Warmest nights on average 8.3 °C at Swan Island
Warmest night 11.3 °C at Eddystone Point on the 11th
Warmest on average overall 10.8 °C at Swan Island
Coolest on average overall 0.4 °C at Mount Wellington
Wettest overall 356.4 mm at Mount Read
Driest overall 27.8 mm at Tunbridge (Austin-Vale)
Wettest day 199.0 mm at Mount Wellington on the 12th
Highest wind gust 137 km/h at Cape Grim BAPS on the 20th

Extremes Maps Records Summaries Important notes the top

Maps

Observed Anomaly Decile 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

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Record highest August daily rainfall

Highest daily rainfall
in August 2010 (mm) 		Previous wettest
for August		 Years of
record
Mangalore (Mangalore Farm) 46.4 on the 12th 44.8 on the 10th in 2007 104
Bothwell (Cluny) 72.2 on the 12th 44.5 on the 17th in 1958 96
Waddamana Field Study Centre 62.8 on the 12th 53.3 on the 17th in 1970 85
Tarraleah Village 72.0 on the 12th 63.5 on the 5th in 1947 74
Levendale 86.0 on the 12th 78.5 on the 17th in 1970 67
Glenorchy (Glenorchy Reservoir) 92.0 on the 12th 81.5 on the 17th in 1970 60
Pyengana (Forest Lodge Road) 135.6 on the 11th 110.7 on the 20th in 1967 49
Huonville (Tutton Avenue) 56.0 on the 12th 45.0 on the 12th in 1984 41
Mount Wellington 199.0 on the 12th 62.4 on the 13th in 2009 30
Risdon Vale (Poplar Road) 84.6 on the 12th 36.6 on the 24th in 1966 30
Nugent (Twilight Valley) 104.0 on the 12th 82.0 on the 12th in 1984 28
Scamander 60.0 on the 11th 58.2 on the 24th in 2003 27
Tea Tree (The Point) 59.2 on the 12th 40.8 on the 10th in 2007 25
Richmond (Strathayr) 46.4 on the 12th 26.8 on the 1st in 1994 23


Record highest total August rainfall

Total rainfall
for August 2010 (mm) 		Previous wettest
for August		 Years of
record		 Average for
August
Risdon Vale (Poplar Road) 127.0 110.4 in 2009 30 49.2
Mount Wellington 263.2 217.8 in 1970 23 73.6
Richmond (Strathayr) 91.0 88.0 in 2009 22 50.5

Highest total August rainfall for at least 20 years

Total rainfall
for August 2010 (mm) 		Most recent August
at least this wet		 Years since
wetter		 Average for
August
Hobart (Ellerslie Road) 107.8 108.6 in 1978 32 53.1
Nugent (Twilight Valley) 205.4 215.2 in 1984 25 82.9


Lowest total August rainfall for at least 20 years

Total rainfall
for August 2010 (mm) 		Most recent August
at least this dry		 Years since
drier		 Average for
August
Macquarie Island 49.4 40.0 in 1989 21 73.4


Extremes Maps Records Summaries Important notes the top


Summary statistics for August 2010

 Maximum temperatures
for August
(°C)		 Minimum temperatures
for August
(°C)		 Rainfall
for August
(millimetres)
Mean for
August
2010		 Diff
from
average		 Highest for
August
2010		 Mean for
August
2010		 Diff
from
average		 Lowest for
August
2010		 Total for
August
2010		 Average
for
August		 Rank of
August
2010		 Fraction of
August
average
Northern (district 91)
Bridport (Sea View Villas) 13.6 -0.1 16.4 2nd 6.0 +0.2 1.0 10th 107.1 87.0 average 123%
Burnie (Round Hill) 13.1 0.0 17.4 2nd 6.5 +0.4 1.9 26th 117.2 109.7 average 107%
Cape Grim BAPS 12.3 -0.4 14.4 30th 7.6 -0.8 4.0 7th 119.8 90.3 average 133%
Cressy Research Station 12.5 -0.5 15.4 12th 2.3 -0.1 -2.3 28th 72.4 73.3 average 99%
Devonport Airport 13.1 0.0 16.8 12th 4.7 -0.3 0.0 28th 74.6 90.2 average 83%
Launceston (Ti Tree Bend) 13.4 -0.4 16.8 12th 3.7 +0.1 -0.9 17th 101.2 86.6 average 117%
Launceston Airport 12.3   15.0 12th 2.7   -2.2 17th 85.8


Low Head 13.1 0.0 17.0 12th 7.2 0.0 2.4 28th 93.2 80.6 average 116%
Luncheon Hill (Forestry) 10.7 -0.6 14.3 13th 4.3 -0.7 1.7 26th 234.8 204.4 high 115%
Marrawah 12.3 -0.4 15.3 30th 6.8 -0.2 2.5 7th 165.2 131.3 high 126%
Scottsdale (West Minstone Road) 11.9 -0.7 14.7 12th 3.3 -0.6 -1.3 17th 119.0 120.5 average 99%
Sheffield School Farm 11.0 -0.7 14.6 2nd 3.4 -0.5 -0.2 30th 175.2 130.4 average 134%
Smithton Aerodrome 13.1 -0.6 15.4 30th 4.5 -0.9 -2.2 7th 128.0 115.9 average 110%
Wynyard Airport 12.9 -0.3 16.0 2nd 3.9 -0.1 -1.2 7th 137.0 112.7 high 122%
East Coast (district 92)
Bicheno (Council Depot) 14.7 0.0 18.3 15th 6.2 -0.1 2.0 8th 103.0 51.0 v high 202%
Eddystone Point 14.4 +0.8 17.4 9th 6.8 -0.4 1.7 28th 93.6 71.5 high 131%
Fingal (Legge Street) 12.6 -0.7 16.0 15th 1.4 +0.2 -4.3 7th 98.0 59.2 high 166%
Friendly Beaches 14.1 -0.6 17.6 15th 5.7 -0.5 1.6 7th 114.4 56.8 v high 201%
Lake Leake (Elizabeth River) 8.8 -0.7 11.6 9th 0.7 0.0 -4.7 7th 150.0 78.4 v high 191%
Maria Island (Point Lesueur) 12.9   15.6 19th 7.2   4.3 7th 97.0


Orford (Aubin Court) 13.2 -0.8 16.8 22nd 3.9 -0.3 -0.6 9th 113.0 61.9 high 183%
Scamander 14.3 -0.5 17.3 11th 5.0 -0.2 1.1 17th 99.4 60.6 high 164%
St Helens Aerodrome 13.8   17.1 30th 4.9   -0.3 17th 94.0 63.9 high 147%
Swan Island 13.3   15.6 14th 8.3   4.8 28th 95.2


Swansea Post Office* 14.0 -0.2 17.7 15th 3.5 -0.9 -1.5 8th 96.3 44.4 v high 217%
Midlands (district 93)
Ross (The Boulevards) 12.2 -0.4 14.4 11th 2.2 -0.1 -4.8 7th 45.8 48.9 average 94%
Southeast (district 94)
Bull Bay (Lauriston) 12.8 -0.5 16.5 19th 5.5 -0.4 1.8 17th 86.4 56.7 high 152%
Campania (Kincora) 14.1 -0.2 17.2 19th 3.2 -0.9 -2.4 7th 78.8 55.6 high 142%
Cape Bruny (Cape Bruny) 12.4 -0.4 16.3 15th 6.2 -0.4 2.7 7th 105.4 93.9 average 112%
Cape Bruny Lighthouse 12.0 +0.1 15.1 15th 6.1 -0.2 2.0 27th 126.2 93.4 high 135%
Dover 12.8 -0.3 15.5 15th 2.7 -1.3 -1.1 7th 122.6 89.6 high 137%
Geeveston (Cemetery Road) 12.5 -0.5 15.7 9th 2.1 -0.8 -1.5 7th 133.0 103.5 high 129%
Grove (Research Station) 13.2   17.4 15th 1.4   -3.3 8th 136.2


Hobart (Ellerslie Road) 13.8 +0.8 18.4 15th 5.3 +0.1 1.5 8th 107.8 53.5 v high 201%
Hobart Airport 13.9 +0.5 18.0 19th 4.6 -0.1 0.6 3rd 65.2 47.0 high 139%
Maatsuyker Island Lighthouse 11.0 -0.2 14.3 9th 6.5 +0.1 3.4 17th 129.4 123.6 average 105%
Melton Mowbray (North Stockman) 12.4 -0.2 16.6 15th 1.4 -1.2 -5.1 3rd 72.6 51.2 average 142%
Mount Wellington 2.6 -0.1 9.0 3rd -1.7 +0.1 -5.5 7th 263.2 81.5 highest 323%
Tasman Island 11.0   14.4 24th 6.2   1.8 17th 99.6


Tunnack Fire Station 10.0 -0.7 13.2 22nd 1.0 -1.1 -6.1 7th 107.4 63.6 high 169%
Derwent Valley (district 95)
Bushy Park (Bushy Park Estates) 13.6 +0.5 16.4 24th 0.6 -1.7 -3.9 8th 70.2 54.0 high 130%
Maydena Post Office 10.9 -1.1 14.5 24th 1.6 -1.0 -2.0 2nd 129.4 155.3 low 83%
Ouse Fire Station 12.8 -0.9 16.1 30th 0.5 -1.6 -4.2 8th 66.8 64.1 average 104%
Tarraleah Village 8.5 -0.9 12.0 15th 0.5 -0.3 -5.0 7th 196.9 127.1 high 155%
Central Plateau (district 96)
Butlers Gorge 7.9 0.0 12.2 13th -0.5 -0.5 -5.6 8th 246.0 183.0 high 134%
Lake St Clair National Park 7.4 -0.8 10.6 13th 0.0 -0.1 -3.5 10th 212.8 250.7 average 85%
Liawenee 5.6   12.0 3rd -1.4   -6.9 7th 147.2 143.2 average 103%
West Coast (district 97)
Hartz Mountain (Keoghs Pimple) 6.2 -0.4 11.9 9th 0.9 -0.6 -2.4 17th 145.6 116.4 high 125%
Mount Read 3.1 -0.9 6.6 13th -0.5 -0.6 -3.5 17th 356.4


Scotts Peak Dam 9.8 -0.5 15.1 9th 2.6 -0.9 -1.5 7th 206.6 215.1 average 96%
Strahan Aerodrome 12.6 -0.5 16.5 9th 5.2 -0.6 -0.2 7th 181.4 158.1 average 115%
Strathgordon Village 9.5 -0.5 13.2 10th 2.9 -0.7 -0.5 7th 256.0 292.7 average 87%
Warra 9.1   12.1 30th 1.8   -3.3 7th 190.8


King Island (district 98)
King Island Airport 13.1 -0.6 15.2 23rd 7.4 -0.4 3.3 7th 161.6 117.3 high 138%
Flinders Island (district 99)
Flinders Island Airport 13.6 -0.1 16.1 9th 5.8 -0.8 -0.4 29th 85.0 75.7 average 112%
Hogan Island 12.6   15.1 15th 8.0   2.6 20th 130.6



* Observations at Swansea have been taken from a new site since September 2008; the new location tends to have lower temperatures during nights in winter than the old site.

Extremes Maps Records Summaries Important notes the top

Notes

A Monthly 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 Wednesday 1 September 2010. 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
Enquiries

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