Tasmania in August 2013: Frequent rain and flooding in the north

August rainfall was well above average across most of Tasmania, and record wet in some parts of the north. Frequent rain throughout the month led to flooding in the north when falls were heavy. Maximum temperatures were close to average. Minimum temperatures were up to 2 °C above average in the north, and up to 1 °C elsewhere.

  • Frequent rain and flooding in the north
  • Launceston's wettest August on record
  • Damaging winds on the 18th
  • −0.4 °C Hobart's coldest August morning in 41 years

A summary for all of winter has also been prepared.

Frequent rain and flooding in the north

August saw the passage of cold fronts and low pressure troughs on most days, and in combination with warmer than usual sea surface temperatures surrounding Tasmania led to frequent rain across the north and west of the state. The rain was heavy at times, notably around the 6th, 14th and 19th, which resulted in flooding as catchments were already saturated. The flooding caused damage to property, landslips and a rock falls. Several roads were closed across the north of the state, with railway lines also affected.

On the evening of the 5th, a short but intense heavy rain event produced daily totals of around 20 to 60 mm across the north and west. Three Hummock Island recorded 36 mm, its highest August daily rainfall on record. The rainfall caused minor flooding in the Meander, Mersey, North Esk, upper South Esk and lower Macquarie river basins, as well as minor flash flooding in the Railton area.

A cold front brought heavy rain to the north and west overnight on the 13th. Daily rainfall totals generally ranged from 30 to 60 mm, peaking at 78 mm at Mount Victoria. Cape Grim BAPS recorded its wettest August day on record with 39.4 mm. There was moderate flooding in the North Esk, Lower Meander and Upper South Esk river basins, and minor flooding in the Mersey and Forth rivers with this event. The heavy rain caused flash flooding around Launceston (Launceston recorded 52 mm over the 24 hours to 9am on the 14th), and in Smithton.

Another cold front crossed overnight on the 16th, followed by a second during the day on the 18th. Daily rainfall totals of around 20 to 40 mm were observed across the north and west on each of those three days. Mount Victoria recorded the highest daily total with 87 mm over the 24 hours to 9am on the 19th. There was moderate flooding in the North Esk, Mersey, Lower Meander, Lower Macquarie, and Upper South Esk river basins, and minor flooding in the Forth river basins. The Launceston area also flooded for a second time in a week.

Record wet in the north overall

August rainfall totals were two to three times the long-term average across northern Tasmania. Sites including Launceston, Scottsdale, Marrawah and Wynyard all had their highest total August rainfall on record, with several other sites observing their wettest August in more than 20 years. Launceston's 233.0 mm is its highest total for any month. This beats the previous monthly record of 183.6 mm set at the current Ti Tree site in August 2005, but is around 35 mm short of the all-time record set at the Launceston City site in August 1936 (254.4 mm).

It rained on almost every day in August across the north and west, with only a handful of rain-free days. Daily rainfall amounts were not as high in the east, resulting in near-average August rainfall totals in the east compared to well-above-average totals elsewhere. Across Tasmania, more than 20 dams were spilling in August due to the above-average rain.

Mount Read was the wettest site overall with at least 740.6 mm (the true total is not known as snow was blown away on some days), whilst Swansea on the east coast was the driest with 21.0 mm.

Damaging winds and snow

A series of cold fronts brought snow showers and strong winds between the 18th and 21st. The cold front on the 18th produced damaging winds across the north, with wind gusts reaching 83 km/h in Launceston, 93 km/h in Wynyard and 98 km/h in Devonport. Cape Grim recorded a wind gust of 157 km/h that evening, followed by a wind gust of 161 km/h in the early hours of the 19th. Thousands of premises lost power in the Launceston area due to downed power lines, including South Launceston, Trevallyn, Kings Meadows and Riverside. Hundreds of premises also lost power around Burnie, Boat Harbour, and Pipers River.

Snow settled down to around 400 m on the 20th, resulting in a number of road closures in the northwest. This followed earlier snow showers between the 12th to 14th, with reports of thick snow in the northwest around the 13th which closed the Anthony Road between Tullah and Queenstown.

Both cool and warm August days

Maximum temperatures were generally on the cool side of average over the first 3 weeks of August due to increased cloud cover and above-average rainfall. The coldest day was on the 20th when maxima remained below 12 °C in a cold southwesterly flow, and there were reports of snow down to 400 m and small hail. Mount Wellington's maximum of −2.6 °C was the coldest day of the month.

The last 9 days of August were warmer than average, maxima rising into the mid to high teens every day. Most sites had their warmest day of the month on the 30th or 31st, Hobart's 19.7 °C on the 30th the highest temperature observed.

Overall, mean maximum temperatures were within one degree of the August average in most areas.

A cold August night

The morning of the 21st was particularly cold, with temperatures dropping below zero in many areas and approaching −7 °C in central regions. Several sites had their coldest August morning in several years: Burnie's minimum of −1.3 °C was its coldest August morning in 18 years and Launceston's −2.5 °C its coldest August morning in 7 years. Liawenee's −7.6 °C that morning was the lowest temperature of the month.

Nights were warmer than average around the 25th, 26th, 30th and 31st due to milder northwest winds and overnight cloud cover. Devonport equalled its warmest August night on record on the 30th with a minimum of 12 °C. The highest minimum temperature of the month was 12.9 °C at Cape Sorell and Flinders Island Airport on the 30th.

Overall, mean minimum temperatures were warmer than average, by up to 2 °C in the north, and up to 1 °C elsewhere.

Hobart's coldest August morning in 41 years, but warm overall

Hobart had a few cold nights in August, the coldest of which was on the 21st when the temperature dropped to −0.4 °C. This was Hobart's coldest morning in 18 years (since −1.0 °C on 6 June 1995) and its coldest August morning in 41 years (since −1.8 °C on 5 August 1962). There were also a few mild nights, Hobart's minimum of 10.2 °C on the morning of the 25th was the warmest of the month. Overall, minimum temperatures were 0.5 °C above average.

The temperature rose to 16 degrees or higher on 10 days, more than double the August average of 4 days. The warmest day was 19.7 °C on the 30th. The coldest day was on the 20th when the temperature only reached 9.8 °C. This was the only day the temperature remained below 10 °C; a typical August sees an average of 4 days. Overall, day-time temperatures were 1.1 °C above average for Hobart.

Hobart recorded 61.0 mm of rain, slightly more than the long-term average of 53.6 mm. The wettest day was on the 13th when a cold front delivered 15 mm over the 24 hours to 9am on the 14th.

Further information

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Extremes in August 2013
Hottest day19.7 °C at Hobart (Ellerslie Road) on the 30th
Warmest days on average15.4 °C at Bicheno (Council Depot)
Coolest days on average2.8 °C at Mount Wellington
Coldest day-2.6 °C at Mount Wellington on the 20th
Coldest night-7.6 °C at Liawenee on the 21st
Coolest nights on average-2.1 °C at Mount Wellington
Warmest nights on average9.2 °C at King Island Airport
Warmest night 12.9 °C at Cape Sorell and at Flinders Island Airport on the 30th
Warmest on average overall11.8 °C at King Island Airport
Coolest on average overall0.4 °C at Mount Wellington
Wettest overall740.6 mm at Mount Read*
Driest overall21.0 mm at Swansea (Francis Street)
Wettest day87.0 mm at Mount Victoria (Una Plain) on the 19th
Highest wind gust161 km/h at Cape Grim BAPS (Comparison) on the 19th

* The true total at Mount Read is probably higher, as it is likely some snow was lost.


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 August daily rainfall
Highest daily rainfall
in August 2013 (mm)
Previous wettest
for August
Years of
record
Cape Grim BAPS (Comparison) 39.4 on the 14th 38.8 on the 2nd in 2007 27
Three Hummock Island 36.2 on the 6th 35.6 on the 12th in 1947 22
Low Rocky Point 43.6 on the 12th 34.0 on the 10th in 2007 20



Record highest total August rainfall
Total rainfall
for August 2013 (mm)
Previous wettest
for August
Years of
record
Average for
August
Naracoopa 332.8 265.3 in 1936 98 129.0
City of Melbourne Bay 350.2 335.4 in 1936 81 140.0
Burnie (Round Hill) 253.5 244.0 in 1955 70 112.3
Forthside Research Station 245.0 239.0 in 1970 47 119.7
Marrawah 306.8 236.0 in 1996 43 136.6
Scottsdale (West Minstone Road) 298.6 269.4 in 1991 43 124.6
Wynyard Airport 334.6 273.1 in 1955 42 120.5
Launceston (Ti Tree Bend) 233.0 183.6 in 2005 34 90.7
Cape Grim BAPS (Comparison) 252.0 208.6 in 2009 27 99.3
Strahan Aerodrome 329.6 324.6 in 1996 26 179.8
Deviot Jetty 255.6 216.2 in 2009 23 108.5
Mount Victoria (Una Plain) 554.0 510.4 in 2011 22 278.9
Three Hummock Island 275.6 196.0 in 2009 22 128.3

Highest total August rainfall for at least 20 years
Total rainfall
for August 2013 (mm)
Most recent August
at least this wet
Years since
wetter
Average for
August
Frankford (Rossville) 315.8 337.7 in 1939 74 128.3
Latrobe (Coal Road) 291.4 410.0 in 1939* 73 116.9
Ringarooma (Charles Street) 379.0 401.2 in 1936* 71 151.7
Northdown (Hamley) 211.8 292.6 in 1939* 70 91.0
Yolla (Sea View) 368.8 409.5 in 1955 58 183.9
Mole Creek 288.2 293.2 in 1970* 42 146.4
Barrington Post Office 293.7 319.1 in 1970* 41 146.6
Lorinna 357.2 437.0 in 1955* 22 182.1
Maatsuyker Island Lighthouse 228.2 255.0 in 1991 22 124.1
Lilydale Post Office 217.0 236.3 in 1991* 21 114.8

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




Record highest August daily minimum temperature
Highest daily minimum
temperature
in August 2013 (°C)
Previous warmest
for August
Years of
record
Average for
August
Devonport Airport 12.0 on the 30th = 12.0 on the 30th in 2005 22 5.1



Summary statistics for August 2013
Maximum temperatures
for August
(°C)
Minimum temperatures
for August
(°C)
Rainfall
for August
(millimetres)
Mean for
August
2013
Diff
from
average
Highest for
August
2013
Mean for
August
2013
Diff
from
average
Lowest for
August
2013
Total for
August
2013
Average
for
August
Rank of
August
2013
Fraction of
August
average
Northern (district 91)
Bridport (Sea View Villas) 13.5 -0.2 16.7 29th 5.2 -0.6 -1.1 21st 232.9 95.8 v high 243%
Burnie (Round Hill) 13.6 +0.5 17.3 26th 7.2 +1.1 1.3 21st 253.5 112.3 highest 226%
Burnie NTC AWS 13.1   16.0 27th 7.4   2.4 21st
Cape Grim 12.9   15.7 31st 8.6   4.7 21st 288.4
Cape Grim BAPS (Comparison) 13.1 +0.4 16.0 31st 8.5 +0.2 4.8 21st 252.0 99.3 highest 254%
Cressy Research Station 12.9 -0.1 16.5 26th 3.5 +0.9 -4.1 21st 144.0 76.1 high 189%
Devonport Airport 13.3 +0.2 15.8 29th 6.3 +1.2 -0.9 21st
Launceston (Ti Tree Bend) 14.0 +0.2 17.8 29th 4.5 +0.8 -2.5 21st 233.0 90.7 highest 257%
Launceston Airport 12.7   16.6 29th 3.5   -3.2 21st 211.8 95.7 high 221%
Low Head 13.2 +0.1 16.0 31st 8.3 +0.9 0.5 21st 192.2 89.5 v high 215%
Marrawah 12.9 +0.2 16.5 31st 7.6 +0.6 1.8 21st 306.8 136.6 highest 225%
Scottsdale (West Minstone Road) 12.2 -0.4 15.7 31st 4.3 +0.4 -2.0 21st 298.6 124.6 highest 240%
Sheffield School Farm 11.1 -0.6 14.9 26th 4.0 +0.1 -2.4 21st 309.6 144.7 v high 214%
Smithton Aerodrome 13.5 -0.2 16.2 31st 5.9 +0.5 -1.6 21st 286.6 129.2 v high 222%
Wynyard Airport 13.2 -0.1 16.9 27th 4.8 +0.7 -2.5 21st 334.6 120.5 highest 278%
East Coast (district 92)
Bicheno (Council Depot) 15.4 +0.7 19.5 30th 6.9 +0.5 2.6 5th 40.5 51.0 average 79%
Fingal (Legge Street) 13.3 0.0 17.8 31st 2.0 +0.7 -4.9 21st 85.4 60.6 high 141%
Friendly Beaches 15.3 +0.6 19.4 31st 6.4 +0.1 0.2 5th 34.6 56.6 low 61%
Lake Leake (Elizabeth River) 9.6 +0.1 13.9 31st 0.9 +0.1 -6.6 21st 104.4 79.3 high 132%
Larapuna (Eddystone Point) 14.3 +0.6 17.3 31st 7.6 +0.4 1.9 21st 95.4 72.1 high 132%
Maria Island (Point Lesueur) 13.8   17.3 31st 7.5   3.7 21st 48.4 43.7 average 111%
Orford (Aubin Court) 14.3 +0.3 19.4 31st 4.0 -0.2 -2.1 21st 61.2 62.1 average 99%
Spring Bay NTC AWS 13.8   17.6 31st 6.4   2.0 5th
St Helens Aerodrome 14.5 +0.2 18.1 31st 5.5 +0.1 -0.9 21st
Swan Island 13.5 0.0 15.6 31st 8.7 +0.2 2.2 21st 135.0
Swansea (Francis Street) 15.2   19.4 31st 4.9   -1.1 21st 21.0
Midlands (district 93)
Ross (The Boulevards) 12.4 -0.2 16.3 25th 3.1 +0.7 -5.4 21st 85.0 50.1 high 170%
Southeast (district 94)
Bull Bay (Lauriston) 13.7 +0.4 18.0 31st 6.0 0.0 2.5 5th 40.6 56.0 low 73%
Campania (Kincora) 14.0 -0.3 19.1 31st 4.4 +0.2 -2.1 5th 58.2 55.5 average 105%
Cape Bruny (Cape Bruny) 12.8 -0.1 18.1 31st 6.4 -0.3 2.2 21st 99.0 90.7 average 109%
Cape Bruny Lighthouse 12.5 +0.6 17.2 31st 6.4 +0.1 2.3 21st 106.0 93.1 high 114%
Dennes Point 13.3   16.6 31st 6.8   2.4 5th 41.6
Dover 13.0 -0.1 18.8 30th 4.1 0.0 -1.5 21st 131.2 90.2 high 145%
Dunalley (Stroud Point) 13.7   18.8 30th 6.8   1.7 5th 54.0
Geeveston (Cemetery Road) 12.9 -0.1 18.0 30th 3.6 +0.6 -2.7 21st 158.4 105.5 high 150%
Grove (Research Station) 13.4   18.4 29th 2.7   -4.0 21st 101.8 89.3 average 114%
Hobart (Ellerslie Road) 14.2 +1.1 19.7 30th 5.7 +0.5 -0.4 21st 61.0 53.7 high 114%
Hobart Airport 14.1 +0.6 19.4 31st 5.0 +0.3 0.3 5th 50.0 47.2 average 106%
Maatsuyker Island Lighthouse 11.5 +0.3 17.8 31st 6.6 +0.1 3.2 20th 228.2 124.1 v high 184%
Melton Mowbray (North Stockman) 12.7 +0.1 17.6 31st 3.2 +0.5 -3.5 5th 59.6 52.3 average 114%
Mount Wellington 2.8 +0.1 9.3 31st -2.1 -0.4 -7.3 21st
Tasman Island 11.6 +0.1 17.7 31st 6.2 -0.4 3.1 21st 76.0 79.0 average 96%
Tunnack Fire Station 10.3 -0.3 14.4 31st 1.8 -0.3 -5.2 5th 58.0 65.7 average 88%
Derwent Valley (district 95)
Bushy Park (Bushy Park Estates) 13.6 +0.5 18.4 31st 2.1 -0.3 -3.8 21st
Maydena Post Office 10.8 -1.2 16.3 31st 2.6 -0.1 -3.1 21st 244.0 157.2 v high 155%
Ouse Fire Station 13.0 -0.7 18.8 31st 2.3 +0.1 -3.0 21st 93.2 64.1 average 145%
Central Plateau (district 96)
Butlers Gorge 7.8 -0.1 13.5 31st 0.3 +0.2 -6.6 21st 377.8 185.3 v high 204%
Lake St Clair National Park 7.6 -0.6 13.7 31st 0.3 0.0 -6.6 21st        
Liawenee 5.9 -0.8 10.6 31st -0.9 +0.1 -7.6 21st 197.8 145.6 high 136%
West Coast (district 97)
Cape Sorell 13.1 +1.0 18.3 29th 7.9 +0.6 3.8 21st 204.0 150.2 high 136%
Hartz Mountain (Keoghs Pimple) 5.5 -1.2 11.3 29th 0.5 -1.0 -2.8 21st
Low Rocky Point 12.8   18.3 31st 6.8   2.6 21st 231.2 153.8 v high 150%
Mount Read 3.8 -0.3 9.4 31st -0.5 -0.6 -3.9 20th
Scotts Peak Dam 9.8 -0.6 15.7 29th 3.0 -0.6 0.0 20th 379.4 224.3 v high 169%
Strahan Aerodrome 13.0 -0.1 18.6 31st 6.0 +0.2 -0.2 8th 329.6 179.8 highest 183%
Warra 9.1   14.3 31st 2.0   -2.9 8th 377.4
King Island (district 98)
King Island Airport 14.2 +0.5 19.6 31st 9.2 +1.4 3.9 21st
Flinders Island (district 99)
Flinders Island Airport 14.4 +0.6 17.8 31st 8.3 +1.7 -1.6 21st 152.2 77.6 v high 196%
Antarctica and Macquarie Island (district 300)
Macquarie Island 5.7 +0.6 7.5 20th 2.5 +0.9 -1.8 28th 104.4 73.8 high 141%

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 11 am on Sunday 1 September 2013. 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.

The ACORN-SAT dataset is being used for temperature area averages from December 2012 onwards. The major change from earlier datasets is that the ACORN-SAT dataset commences in 1910, rather than 1950, and hence rankings are calculated using a larger set of years.

Further information

Media
(03) 9669 4057
Enquiries