Monday, 1 June 2009 - Seasonal Climate Summary for Tasmania - Product code IDCKGC27R0

Tasmania in autumn 2009: Mostly near average rain but still dry in the central east and northeast coast

A few heavy rainfall events led to near average autumn rain over much of the state and even above average totals in the west and southeast, but it was another dry season for the central east and northeast coast. There were several windy days, and gusts reached almost 200 km/h at Scottsdale during April - most likely from a tornado. Temperatures were generally warmer than usual, but there no really hot days and some very cold periods, especially near the end of April.

An archive of previous seasonal summaries for Tasmania is also available, as are summaries for other states and many other climate summaries and diagnostics.

Details

Some good falls give near average rain to most areas: There was significant rain on the 14−16th March, 24−26th April and 14−16th May and moderate falls on a number of other occasions, so rainfall totals for autumn were near average for most of the state. It was wetter than normal in most of the southeast, where it was the wettest autumn since 2003, and in parts of the west. But the central east and northeast coast endured another season of below average rain. Swansea Post Office was the driest overall, with only 69.8 mm for the 3 months, while Mount Read was the wettest with 1175 mm. The highest daily rainfall for autumn was in the 24 hours to 9 am on the 15th May, when a cold front delivered 140.6 mm to Mount Read; this is around double the total autumn rain received by some sites in the east. Great Bay (Robeville) had its highest autumn daily rainfall on record on the 15th March as a complex low pressure system crossed the state.

Not many hot days but several cold periods: Although there were many days when maxima were warmer than usual, there were few hot days. Ouse reached 30.5°C on the 21st March, which was the highest temperature for autumn. There were several cold days, even at the start of March, but the coldest period was the 26−29th April when temperatures struggled to reach the low teens. Mount Wellington's maximum of −1.9°C on the 27th April was the coldest autumn day. Snow fell to 600 metres or lower on three occassions, and was even observed falling at Bothwell (350 metres) on the 16th May. The final few days of May were also quite cold. Overall, mean maxima for autumn were mostly around half a degree cooler than usual in the west and south and within half a degree of average elsewhere.

Some very cold nights but above average overall: The warm nights in March and at the start of April more than compensated for the cold nights at end of April and in much of May, so mean minima for autumn were near normal in the west, far south and northeast but half to one degree warmer than usual elsewhere. Wynyard and Grove had their equal highest autumn mean minimum temperature on record. The coldest nights were on the 29th and 30th of April when overnight temperatures fell well below zero at many sites and Liawenee fell to −7.5°C, the coldest temperature recorded this autumn. Dover dropped to −2.0°C early on the 30th April, beating its previous lowest autumn temperature on record by half a degree. Very frosty conditions were experienced in many parts of the state on both the 29th and 30th April, as well as the 18th and 19th May.

Damaging winds and tornadoes: There were several windy days during autumn and damage was sustained on the 15th April, 26th April and 17th May. Scottsdale registered a wind gust of 194 km/h on the 15th April, just short of the strongest gust ever recorded in Tasmania of 200 km/h on Mount Wellington. The damage pattern, along with other reports from the north of the state, suggests a tornado moved through the area.

Further information

Ian Barnes-Keoghan
Meteorologist
Tasmania and Antarctica Climate Services Centre
Bureau of Meteorology
Phone (03) 6221 2043
Email climate.tas@bom.gov.au

Extremes

Hottest day
Highest temperature
30.5°C at Ouse Fire Station on 21 Mar
Warmest days on average
Highest mean daily maximum temperature
19.3°C at Launceston (Ti Tree Bend)
Coolest days on average
Lowest mean daily maximum temperature
8.1°C at Mount Wellington
Coldest day
Lowest daily maximum temperature
−1.9°C at Mount Wellington on 27 Apr
Coldest night
Lowest temperature
−7.5°C at Liawenee on 29 Apr
Coolest nights on average
Lowest mean daily minimum temperature
2.2°C at Mount Wellington
Warmest nights on average
Highest mean daily minimum temperature
12.7°C at Hogan Island
Warmest night
Highest daily minimum temperature
19.7°C at Flinders Island Airport on 22 Mar
Wettest overall
Highest total rainfall
1174.6 mm at Mount Read
Driest overall
Lowest total rainfall
69.8 mm at Swansea Post Office
Wettest day
Highest daily rainfall
140.6 mm at Mount Read on 15 May
Highest wind gust
194 km/h at Scottsdale (West Minstone Road) on 15 Apr

Records

Record highest autumn daily rainfall
Highest daily rainfall
in autumn 2009 (mm)
Previous highest
for autumn
Years of
record
Great Bay (Robeville) 78.0 on 15 Mar 75.0 on 21 Mar 2003 25



Record lowest autumn temperature
Lowest temperature
in autumn 2009 (°C)
Previous lowest
for autumn
Years of
record
Average for
autumn
Dover −2.0 on 30 Apr −1.5 on 31 May 2006 20 7.3




Record highest autumn mean daily minimum temperature
Mean daily minimum
temperature
for autumn 2009 (°C)
Previous highest
for autumn
Years of
record
Average for
autumn
Grove (Comparison) 7.5 = 7.5 in 1980 51 6.2
Wynyard Airport 8.4 = 8.4 in 2007 23 7.2



Summaries

In this table, key sites have been highlighted to make them easier to find. This table is very wide and may not fit if printed.


Summary statistics for autumn 2009
Maximum temperatures
for autumn
(°C)
Minimum temperatures
for autumn
(°C)
Rainfall
for autumn
(millimetres)
Mean for
autumn
2009
Diff
from
average
Highest for
autumn
2009
Mean for
autumn
2009
Diff
from
average
Lowest for
autumn
2009
Total for
autumn
2009
Average
for
autumn
Rank of
autumn
2009
Fraction of
autumn
average
Northern (district 91)
Bridport 18.0 −0.3 25.0 22 Mar 10.0 +0.5 2.2 28 Apr 193.9 160.5 high 121%
Burnie 17.9 +0.2 24.6 1 Mar 11.1 +1.1 3.8 18 May 196.0 218.9 average 90%
Cape Grim BAPS 16.0 −0.5 21.1 10 Mar 11.4 −0.1 4.9 28 Apr 216.6 181.6 average 119%
Cressy Research Station 18.7   28.1 21 Mar 6.6   −4.7 18 May 106.0
Devonport Airport 18.0 +0.4 25.3 22 Mar 9.7 +1.1 1.1 18 May 128.0 180.8 low 71%
Launceston 19.3 +0.3 27.2 22 Mar 8.2 +0.8 −0.6 30 Apr 143.1 147.9 average 97%
Launceston Airport 18.2   27.3 21 Mar 7.1   −1.3 30 Apr 153.6
Launceston Airport Comparison 17.5 +0.1 26.4 21 Mar 7.4 +0.7 −1.6 30 Apr 165.2 152.6 average 108%
Low Head 17.3 −0.3 23.8 22 Mar 11.6 +0.5 3.7 29 Apr 158.0 145.2 average 109%
Luncheon Hill 15.4 −0.3 25.0 21 Mar 8.4 +0.3 0.3 28 Apr 399.6 344.3 high 116%
Marrawah 16.4 −0.6 22.7 21 Mar 10.3 0.0 3.5 28 Apr 264.2 252.7 average 105%
Scottsdale 17.6 −0.4 25.8 13 Mar 8.2 +0.4 −0.3 6 Apr 229.6 231.8 average 99%
Sheffield School Farm 16.8 +0.2 25.1 21 Mar 7.4 +0.3 −1.5 29 Apr 242.0
Smithton Aerodrome 17.4 −0.4 22.7 1 Mar 8.3 +0.7 −1.0 19 May 234.8 178.6 high 131%
Wynyard Airport 17.8 +0.3 24.3 22 Mar 8.4 +1.2 −1.1 29 Apr 258.3 217.9 high 119%
East Coast (district 92)
Bicheno 19.0 +0.4 28.2 29 Mar 11.0 +0.8 3.3 30 Apr 77.4 171.7 very low 45%
Eddystone Point 18.9 +0.9 24.5 19 Mar 11.6 +0.2 5.0 6 Apr 114.0 188.8 low 60%
Fingal 18.3 −0.1 30.2 21 Mar 6.2 +0.9 −4.8 30 Apr 79.8 145.6 low 55%
Friendly Beaches     28.1 19 Mar 10.5 +0.7 1.5 30 Apr
Lake Leake 14.6 +0.3 25.6 21 Mar 4.2 +0.1 −5.9 29 Apr 107.4 205.1 low 52%
Maria Island 17.4   24.2 13 Mar 11.3   5.1 16 May 107.0
Orford 17.9 −0.3 25.7 28 Mar 9.0 +0.6 0.5 30 Apr 113.7 160.3 average 71%
Scamander 18.7 0.0 27.9 29 Mar 10.0 +0.3 2.2 30 Apr 81.9 182.5 very low 45%
St Helens Aerodrome 18.5   26.3 29 Mar 10.0   1.3 30 Apr 87.6
Swan Island 17.7   22.2 21 Mar 12.5   6.2 28 Apr 131.4
Swansea Post Office 18.5 0.0 30.0 21 Mar 8.4 +0.2 −0.5 30 Apr 69.8 148.0 low 47%
Midlands (district 93)
Ross 18.2 +0.4 28.7 13 Mar 6.8 +1.3 −4.0 29 Apr 78.2 93.2 average 84%
Southeast (district 94)
Bull Bay 17.0 −0.3 25.0 19 Mar 9.8 +0.2 2.6 30 Apr 212.0 129.7 high 163%
Campania 18.4   30.1 21 Mar 8.2   −1.4 30 Apr 116.0
Cape Bruny 16.1 −0.3 24.3 21 Mar 10.0 +0.1 3.7 29 Apr 205.4 163.5 high 126%
Cape Bruny Lighthouse 15.6 +0.1 23.5 3 Mar 9.9 +0.3 3.3 17 May 245.0 232.3 average 105%
Dover     25.5 3 Mar 7.1 −0.1 −2.0 30 Apr 227.8 203.0 high 112%
Geeveston 17.1 −0.2 28.2 21 Mar 7.3 +0.9 −2.8 30 Apr 254.6 193.0 high 132%
Grove 17.5 0.0 29.7 21 Mar 7.5 +1.3 −1.8 1 May 199.6 168.2 high 119%
Grove 17.2   29.2 21 Mar 6.8   −2.1 30 Apr 221.0
Hobart 17.7 +0.5 26.5 19 Mar 9.6 +0.7 1.3 30 Apr 188.0 143.0 high 131%
Hobart Airport 17.9 −0.1 26.1 28 Mar 9.5 +0.8 1.3 30 Apr 138.6 114.2 high 121%
Maatsuyker Island Lighthouse 14.2 −0.3 25.5 2 Apr 9.9 +0.4 4.2 16 May 254.0 308.9 average 82%
Melton Mowbray 17.0 −0.4 30.3 21 Mar 7.1 +1.1 −3.3 29 Apr 105.8 87.1 average 121%
Mount Wellington 8.1 −0.3 19.8 21 Mar 2.2 0.0 −5.6 6 Apr
Tasman Island 14.6   22.8 13 Mar 9.6   3.6 6 Apr 226.6
Tunnack Fire Station 14.9 −0.6 25.0 21 Mar 6.1 +0.8 −4.1 30 Apr 158.8 133.9 average 119%
Derwent Valley (district 95)
Bushy Park 18.1 +0.1 29.8 13 Mar 6.3 +0.1 −3.5 30 Apr 115.2 131.6 average 88%
Maydena Post Office 15.7 −0.5 28.5 21 Mar 6.3 +0.9 −1.4 30 Apr 261.0 251.2 average 104%
Ouse Fire Station 17.7 −0.8 30.5 21 Mar 5.8 +0.5 −5.6 30 Apr 124.4
Tarraleah Village 13.9 −0.2 25.6 21 Mar 4.8 +0.8 −1.7 29 Apr 299.3 268.7 high 111%
Central Plateau (district 96)
Butlers Gorge 13.3 +0.2 24.9 21 Mar 3.7 +0.4 −4.6 29 Apr 437.2 407.0 high 107%
Lake St Clair National Park 13.0 −0.3 24.2 21 Mar 3.4 +0.6 −4.4 29 Apr 437.6 414.6 average 106%
Liawenee 12.1   22.6 21 Mar 2.3   −7.5 29 Apr 174.8
West Coast (district 97)
Hartz Mountain 11.0 −0.5 24.3 21 Mar 4.6 −0.1 −1.6 28 Apr 260.0 208.9 very high 124%
Mount Read 8.7 −0.4 20.8 21 Mar 3.5 +0.1 −2.9 28 Apr 1174.6 943.3 very high 125%
Scotts Peak Dam 14.6 −0.1 28.1 13 Mar 6.7 0.0 −0.4 29 Apr 473.8
Strahan Aerodrome 16.5 −0.2 27.8 21 Mar 8.4 0.0 0.8 30 May 417.6 354.9 high 118%
Strathgordon Village 13.9 −0.5 25.5 21 Mar       662.0 591.5 average 112%
Warra 13.4   25.5 21 Mar 6.0   −2.5 29 Apr 473.2
King Island (district 98)
King Island Airport 17.4 −0.3 29.8 21 Mar 10.6 +0.2 1.3 29 Apr 190.6 190.5 average 100%
Flinders Island (district 99)
Flinders Island Airport 18.6 −0.1 30.2 21 Mar 10.5 −0.2 −0.3 30 Apr 133.8 188.5 low 71%
Hogan Island 17.5   25.8 22 Mar 12.7   7.3 28 Apr 160.0
Antarctica and Macquarie Island (district 300)
Macquarie Island 7.2 +0.2 9.7 3 Mar 4.3 +0.7 0.3 8 May 248.2 275.9 low 90%

Notes

This statement has been prepared based on information available at 9 am on Monday 1 June 2009. 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

Ian Barnes-Keoghan
Meteorologist
Tasmania and Antarctica Climate Services Centre
Bureau of Meteorology
Phone (03) 6221 2043
Email climate.tas@bom.gov.au