Tuesday, 3 March 2009 - Monthly Climate Summary for Tasmania - Product code IDCKGC17R0

Tasmania in February 2009: Some heavy rain, several cold nights and few hot days

February did not see many especially hot days, but did have several quite cold nights. Rainfall was close to average in many parts of the state, mostly the result of some heavy falls in the final week, but there was very little rain in the north and especially on the Bass Strait Islands.

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

Details

Heavy rain and thunderstorms: On the evening of the 23rd, a low pressure system developed over southern Tasmania as a cold front crossed the state. The low stalled near the southeast on the 24th and heavy rain fell in the west and south, including in the southern Midlands and Coal River Valley. Over 100 mm fell in elevated areas of the west and many parts of the southeast and southern Midlands received 30 to 50 mm, but very little rain reached the north. There was minor flooding of the Huon River at Tahune Bridge. Strathgordon Village received 92.4 mm in the 24 hours to 9 am on the 24th, its highest daily rainfall on record for February, and Hobart's 47.2 mm (over two days) was its highest rainfall from one event since January 2007. Ahead of the rain, on the evening of the 23rd, thunderstorms produced hail and damaging winds gusts in western, central and southern areas. Winds gusted to 100 km/h in Hobart. There was another outbreak of thunderstorms on the 20th, bringing heavy rain and gusty winds to the northeast and northern Midlands. On this occasion, several sites received in excess of 20 mm; the highest was 46.6 mm at Mathinna. A total of 16 mm fell at Launceston Airport in under 20 minutes, flooding a house, reducing visibility to below 400 metres and contributing to some car crashes.

Above average rain totals, except in the north: Although many February days had very little rain, rainfall for the whole month was near or above average in all but the north. This was mostly due to the rain on the 20th and 24th, but there were also moderate rainfall totals in the west and central east with troughs on the 2nd and 7th. In the north, rainfall totals were mostly below 20 mm, and several sites along the coast and on the Bass Strait islands had less than 10 mm. King Island Airport was the driest location, recording only 1.4 mm for the month and it, along with Naracoopa, had its driest February on record and other sites on King and Flinders Islands had their driest February for at least 20 years.

Not many hot days: There was a lack of very hot days in February, with temperatures exceeding 30°C on only three days. All of these occurred between the 4th and 7th when a high pressure system persisted over the Tasman Sea and the airflow over Tasmania was predominately northerly. Hogan Island reached 38.4°C on the 7th, and Flinders Island recorded 37.9°C, but otherwise Tasmania avoided the extremely hot temperatures that were experienced in Victoria during this time. There was a run of cool days from the 9th to the 12th when a slow moving high over the Bight directed a southerly airflow over the state for a number of days and temperatures struggled to reach 20°C. It was also cool on the 24th, and in the east on the 16th when winds were easterly, but for the rest of the month daytime temperatures were mostly near average. Over the whole month, maxima were up to a degree warmer than usual in the western half of the state, but one to two degrees below normal in the east. The mean daily maximum temperatures at Swansea, Orford and Lake Leake were their lowest for February since 1996.

Some very cold nights: Over the whole month, overnight temperatures were generally within half a degree of normal, except for most of the southeast which was one to two degrees cooler than normal. This was despite several warm nights in the first and third weeks. There was a run of cold nights from the 9th to the 15th when a southerly airflow persisted for a few days before a ridge of high pressure moved over the state. During this time, temperatures were up to nine degrees below average. Liawenee recorded −3.6°C early on the 13th; only three temperatures colder than this have ever been measured in Tasmania during February. Bushy Park, a site with records since 1957, had eight nights below 6°C this month; usually there are only four. Bushy Park, along with Dover, Grove and Geeveston, had its coolest February nights on average since the early 1990s.

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
38.4°C at Hogan Island on the 7th
Warmest days on average
Highest mean daily maximum temperature
25.0°C at Ouse Fire Station
Coolest days on average
Lowest mean daily maximum temperature
12.2°C at Mount Wellington
Coldest day
Lowest daily maximum temperature
5.1°C at Mount Wellington on the 12th
Coldest night
Lowest temperature
−3.6°C at Liawenee on the 13th
Coolest nights on average
Lowest mean daily minimum temperature
4.4°C at Mount Wellington
Warmest nights on average
Highest mean daily minimum temperature
15.3°C at Hogan Island
Warmest night
Highest daily minimum temperature
18.7°C at Flinders Island Airport on the 5th
Wettest overall
Highest total rainfall
174.0 mm at Mount Read
Driest overall
Lowest total rainfall
1.4 mm at King Island Airport
Wettest day
Highest daily rainfall
92.4 mm at Strathgordon Village on the 24th
Highest wind gust
109 km/h at Maatsuyker Island Lighthouse on the 8th
109 km/h at Mount Wellington on the 24th

Records

Record highest February daily rainfall
Highest daily rainfall
in February 2009 (mm)
Previous highest
for February
Years of
record
Strathgordon Village 92.4 on the 24th 56.4 on the 22nd in 1969 41



Record lowest total February rainfall
Total rainfall
for February 2009 (mm)
Previous lowest
for February
Years of
record
Average for
February
Naracoopa 4.6 6.4 in 1965 96 42.4
King Island Airport 1.4 3.0 in 1983 36 30.3

Lowest total February rainfall for at least 20 years
Total rainfall
for February 2009 (mm)
Most recent lower
for February
Years since
lower
Average for
February
City of Melbourne Bay 6.6 5.3 in 1936 73 44.7
Yambacoona 2.4 0.5 in 1965 41 36.5



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 February 2009
Maximum temperatures
for February
(°C)
Minimum temperatures
for February
(°C)
Rainfall
for February
(millimetres)
Mean for
February
2009
Diff
from
average
Highest for
February
2009
Mean for
February
2009
Diff
from
average
Lowest for
February
2009
Total for
February
2009
Average
for
February
Rank of
February
2009
Fraction of
February
average
Northern (district 91)
Bridport 21.9 −0.3 29.1 7th 12.9 −0.2 8.0 9th 7.0 31.4 low 22%
Burnie 21.7 +0.6 26.4 7th 14.1 +0.9 8.0 12th 10.0 45.0 low 22%
Cape Grim BAPS 19.7 +0.2 23.3 19th 13.6 −0.2 8.8 12th 7.4 32.4 very low 23%
Cressy Research Station 24.8   30.7 5th 10.6   3.2 9th 22.6 20.7 average 109%
Devonport Airport 21.9 +0.4 27.2 7th 12.6 +0.2 6.8 9th 11.6 36.0 low 32%
Launceston 24.9 +0.4 30.3 7th 12.7 +0.7 6.4 9th 38.6 31.0 average 125%
Launceston Airport 24.2   29.0 5th 10.9   5.3 12th 47.6
Launceston Airport Comparison 23.4 +0.3 28.0 5th 11.0 +0.7 5.5 9th 49.8 38.7 high 129%
Low Head 20.6 −0.4 25.2 7th 14.0 −0.5 9.8 13th 6.0 23.7 low 25%
Luncheon Hill 21.2 +0.1 25.8 19th 10.3 −0.4 4.5 12th 24.8 54.7 low 45%
Marrawah 21.1 +0.2 24.3 19th 12.2 −0.2 7.5 11th 16.6 43.5 low 38%
Scottsdale 23.0 −0.1 30.5 7th 11.2 +0.1 6.9 13th 29.6 39.3 average 75%
Sheffield School Farm 22.6 +1.2 28.8 5th 10.6 −0.1 4.3 12th 25.0 37.3 average 67%
Smithton Aerodrome 21.6 −0.2 26.0 7th 11.1 −0.5 3.1 9th 6.0 30.2 low 20%
Wynyard Airport 22.1 +0.6 28.2 5th 12.1 +0.7 3.3 9th 11.8 47.7 low 25%
East Coast (district 92)
Bicheno 20.6 −0.7 25.6 7th 13.1 +0.1 9.9 11th 43.6 58.0 average 75%
Eddystone Point 21.3 +0.2 29.5 5th 14.2 +0.1 10.6 12th 27.4 46.8 average 59%
Fingal 21.4 −1.4 31.0 5th 10.8 +0.9 3.6 14th 52.6 40.7 high 129%
Friendly Beaches 21.0 −1.8 27.8 5th 12.4 −0.9 7.7 14th 57.8 60.3 average 96%
Lake Leake 17.4 −1.6 26.2 7th 7.5 −0.7 1.8 14th 47.2 45.7 average 103%
Maria Island 19.9   27.3 5th 13.1   9.5 13th 28.0
Orford 20.1 −1.8 28.3 5th 11.7 −0.4 7.1 13th 46.4 45.0 average 103%
Scamander 20.4 −1.3 30.5 5th 13.1 +0.3 9.0 14th 39.8 42.5 average 94%
St Helens Aerodrome 20.9   31.7 5th 13.0   7.6 12th 57.4
Swan Island 20.2   25.0 5th 14.5   10.6 12th 6.2
Swansea Post Office 20.1 −2.1 30.1 5th 11.5 −0.2 6.3 14th 51.2 42.7 average 120%
Midlands (district 93)
Ross 23.0 −1.2 30.3 5th 10.8 +0.2 3.5 13th 49.4 38.2 high 129%
Southeast (district 94)
Bull Bay 20.2 −1.0 25.5 5th 11.8 −0.8 7.2 13th 41.2 42.7 average 96%
Campania 22.7   30.9 5th 10.8   3.8 13th 41.2
Cape Bruny 19.5 −0.3 25.6 27th 12.0 −0.4 8.3 13th 49.2 62.2 average 79%
Cape Bruny Lighthouse 18.5 +0.1 25.2 27th 12.1 +0.4 8.6 10th 56.2 56.8 average 99%
Dover 19.6 −1.0 24.5 5th 8.7 −1.6 3.2 13th 54.4 51.5 average 106%
Geeveston 21.4 −0.7 28.0 27th 8.5 −1.3 2.0 13th 72.8 50.2 high 145%
Grove 22.3 −0.1 28.9 27th 8.5 −1.0 1.5 13th 66.8 47.1 high 142%
Grove 22.0   28.8 27th 8.0   0.6 10th 71.4
Hobart 21.2 −0.4 30.1 5th 12.1 0.0 7.5 11th 59.4 40.3 high 147%
Hobart Airport 21.8 −0.5 29.4 5th 11.7 −0.3 6.5 13th 38.0 36.6 average 104%
Maatsuyker Island Lighthouse 17.7 +0.5 25.2 27th 11.7 +0.6 8.6 11th 79.4 70.3 average 113%
Melton Mowbray 22.5 −1.1 28.2 4th 9.9 −0.3 2.9 13th 41.2 35.6 high 116%
Mount Wellington 12.2 −1.5 19.2 27th 4.4 −1.0 −1.2 11th 75.0 79.5 average 94%
Tasman Island 16.8   23.7 5th 11.1   7.7 11th 27.6
Tunnack Fire Station 20.0 −1.4 27.8 5th 8.5 −0.6 0.4 13th 71.8 47.3 high 152%
Derwent Valley (district 95)
Bushy Park 24.1 +0.2 31.1 4th 8.8 −1.2 3.5 13th 34.6 35.1 average 99%
Maydena Post Office 22.1 −0.2 29.0 4th 7.8 −1.1 1.5 10th 57.4 64.7 average 89%
Ouse Fire Station 25.0 −0.2 31.0 4th 9.6 −0.3 2.3 13th 26.4 30.3 average 87%
Tarraleah Village 20.3 +0.5 27.0 5th 7.2 +0.2 0.9 12th 45.1 60.4 average 75%
Central Plateau (district 96)
Butlers Gorge 19.3 +0.6 26.5 4th 5.5 −0.7 −1.6 12th 73.0 82.2 average 89%
Lake St Clair National Park 19.1 −0.1 25.4 4th 5.6 −0.3 −0.7 12th 90.2 82.7 average 109%
Liawenee 17.5   23.4 7th 5.0   −3.6 13th 43.6
West Coast (district 97)
Hartz Mountain 17.0 −0.6 24.1 4th 6.4 −0.9 2.1 11th 105.8 66.0 high 160%
Mount Read 14.6 +0.4 20.5 4th 6.2 0.0 0.0 11th 174.0 173.1 average 101%
Scotts Peak Dam 21.9 +1.2 29.0 4th 8.8 −0.5 4.5 13th 104.0 74.0 high 141%
Strahan Aerodrome 21.2 +0.1 27.8 27th 9.8 −0.9 4.9 12th 57.2 64.6 average 89%
Strathgordon Village 20.5 +0.9 26.0 4th 10.4 +0.8 3.4 12th 138.6 110.3 high 126%
Warra 18.9   24.4 4th 7.3   2.1 13th 91.2
King Island (district 98)
King Island Airport 21.3 +0.2 26.1 7th 13.4 +0.5 6.2 6th 1.4 30.3 lowest 5%
Flinders Island (district 99)
Flinders Island Airport 22.8 +0.2 37.9 7th 13.3 −0.3 5.4 10th 2.4 38.3 very low 6%
Hogan Island 21.5   38.4 7th 15.3   12.2 10th 6.2
Antarctica and Macquarie Island (district 300)
Macquarie Island 8.1 −0.5 10.2 23rd 4.8 −0.4 2.0 11th 71.2 84.9 average 84%
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Notes

This statement has been prepared based on information available at 9 am on Tuesday 3 March 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