Tasmania in March 2018: a wet, mild month

Several bursts of wet weather ensured rainfall in March was above average for most of Tasmania, and well above average in parts of the north. Mostly warm weather was replaced by cooler conditions with a front on the 18th, but temperatures were a little above average overall. A strong high pressure system brought record high March pressures.

Bursts of wet weather

  • Monthly rainfall was above average for much of Tasmania, with areas in the northeast and the northwest very much above average; a few sites in the north had their wettest March since at least 1996
  • The total rainfall for the State was about 39% above average
  • There were showers in the northeast on the afternoon and evening of the 16th, with a localised heavy fall of 85 mm at Gray
  • A cloud band ahead of an approaching front brought more rain to all but the southwest on the 17th and 18th; after the front crossed there was more rain in the south and west together with strong and gusty winds
  • A series of troughs and fronts on the 24th and 25th again brought rain statewide, with localised heavy falls in the north and west

A warm month overall

  • Warm weather was dominant in the first half of the month, including some temperatures into the 30s on the 10th and 17th
  • A week or more of cool weather followed a front that crossed on the 18th; at some sites the maximum temperature on the 18th was more than 10 °C cooler than the 17th
  • Tasmania's mean temperature was 0.40 °C above average, much cooler than March last year
  • The State's mean maximum temperature for the month was just 0.11 °C above average, and the mean minimum 0.69 °C above average

Record high pressure

  • After the cold change on the 18th, a high pressure system intensified and moved from south of the Great Australian Bight to be south of Tasmania by the 21st
  • The high was unusually strong for this time of year, with a peak central pressure around 1042 hectopascals
  • Ouse Fire Station reported a mean sea level pressure of 1041.0 hPa at 9 am on the 21st, the highest March pressure ever recorded at an Australian site at a standard synoptic hour
  • Hobart's pressure at 9 am was 1040.5 hPa, a March record for the site where comparable records go back to May 1893
  • All of the reliable observations of pressure over 1040 hPa in Australia in March occurred either on the 21st, or on 12 March 2010
  • The highest pressure recorded in Australia was on 7 June 1967, when Launceston Airport reached 1044.3 hPa
  • Strong high pressure systems close to Australia are more common in the cooler months rather than autumn
  • Slightly higher pressures were registered between 9 am and noon on the 21st, but these cannot be directly compared against records from previous years which are mostly only known at standard synoptic hours (3 am, 6 am, 9 am, and so on)

A warm month for Hobart

  • The mean daily maximum temperature for Hobart (Ellerslie Road) was 21.4 °C, which is 1.3 °C above the long-term average
  • Hobart's warmest day (and the only day over 30 °C) was 30.1 °C on the 17th, and the coolest day was on the 26th when the temperature reached just 15.9 °C
  • The mean daily minimum temperature for Hobart (Ellerslie Road) was 12.4 °C, which is 1.5 °C above the long-term average
  • Hobart's coldest morning was 7.1 °C on the 21st, and the warmest morning was on the 11th when the minimum temperature was 18.2 °C
  • Total rainfall for Hobart (Ellerslie Road) was 38.6 mm, which is 87% of the long-term average of 44.6 mm
  • Hobart's pressure at 9 am on the 21st was 1040.5 hPa, a March record for the site and clear of the 1040.0 hPa from 12 March 2010

Further information

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Extremes in March 2018
Hottest day 31.3 °C at Ouse Fire Station on the 10th
Warmest days on average 22.6 °C at Launceston (Ti Tree Bend)
Coolest days on average 11.0 °C at kunanyi (Mount Wellington Pinnacle)
Coldest day 3.3 °C at kunanyi (Mount Wellington Pinnacle) on the 20th
Coldest night -3.9 °C at Butlers Gorge on the 21st
Coolest nights on average 3.3 °C at Liawenee
Warmest nights on average 14.7 °C at Hogan Island
Warmest night 21.0 °C at Flinders Island Airport on the 18th
Warmest on average overall 17.7 °C at Hogan Island and Swan Island
Coolest on average overall 7.5 °C at kunanyi (Mount Wellington Pinnacle)
Wettest overall 505.6 mm at Mount Read
Wettest day 85.4 mm at Gray (Dalmayne Rd) on the 17th
Strongest wind gust 156 km/h at Maatsuyker Island Lighthouse on the 19th

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 March daily rainfall
New record
(mm)
Old
record
Years of
record
Scotts Peak Dam 43.2 on the 19th 40.0 on the 20th in 2003 20



Record highest March total rainfall
New record
(mm)
Old
record
Years of
record
Average for
March
Derwent Bridge 144.6 127.2 in 2003 21 83.9

Highest March total rainfall for at least 20 years
Observed
(mm)
Most recent
higher
Average for
March
Savage River Mine 205.6 232.0 in 1975* 109.5
Launceston (Kings Meadows) 89.4 92.2 in 1984* 38.3
Zeehan (West Coast Pioneers Museum) 249.7 257.0 in 1996 144.0
Loongana (Serendipity) 189.0 200.0 in 1996* 85.1
Lake Margaret Dam 332.6 339.6 in 1996* 240.6

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



Summary statistics for March 2018
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
March
2018
Diff
from
average
Highest for
March
2018
Mean for
March
2018
Diff
from
average
Lowest for
March
2018
Total for
March
2018
Average
for
March
Rank of
March
2018
Fraction of
March
average
Northern (district 91)
Cape Grim 19.2   24.8 17th 13.1   8.3 21st 56.0
Cape Grim BAPS (Comparison) 19.4 +0.8 25.1 17th 13.0 0.0 8.6 21st 58.4 48.6 high 120%
Cressy Research Station 21.8 -0.9 28.4 11th 8.8 +0.4 2.1 31st 54.0 44.5 high 121%
Devonport Airport 21.2 +0.7 28.9 11th 11.7 +0.7 7.0 20th 75.6 48.2 high 157%
Launceston (Ti Tree Bend) 22.6 0.0 30.2 11th 10.9 +0.6 5.0 31st 81.8 40.0 v high 205%
Launceston Airport 21.6 -1.1 28.0 11th 9.2 -0.3 3.8 31st 82.0 51.8 high 158%
Low Head 20.4 +0.3 24.1 11th 13.8 +0.4 9.2 21st 67.8 48.8 high 139%
Luncheon Hill (Forestry) 18.3 -0.7 24.8 8th 10.2 +0.3 6.3 21st 154.4 89.5 v high 173%
Marrawah 19.4 0.0 25.0 17th 11.8 +0.1 7.5 21st 77.0 67.3 average 114%
Scottsdale (West Minstone Road) 20.4 -0.9 27.1 11th 10.4 +0.4 4.8 27th 117.6 56.5 high 208%
Sheffield School Farm 18.9 -1.1 25.0 11th 9.5 +0.1 3.5 21st
Smithton Aerodrome 20.4 0.0 24.4 17th 10.3 +0.6 4.7 5th 84.6 53.5 high 158%
Wynyard Airport 20.7 +0.4 25.4 11th 10.2 +0.5 4.5 20th 79.2 49.2 high 161%
East Coast (district 92)
Fingal (Legge Street) 21.7 +0.1 27.9 17th 8.3 +0.2 1.4 27th 50.6 44.8 high 113%
Friendly Beaches 22.4 +0.8 29.2 17th 12.4 +0.3 7.5 27th 64.2 56.7 high 113%
Lake Leake (Elizabeth River) 17.8 +0.2 23.5 10th 6.8 +0.6 1.1 31st 73.4 61.7 high 119%
larapuna (Eddystone Point) 21.3 +1.1 26.9 17th 13.5 +0.4 8.6 20th 34.2 58.3 average 59%
Maria Island (Point Lesueur) 20.0 -0.2 26.4 17th 13.4 +0.3 9.6 20th 33.2 34.0 average 98%
Orford (Aubin Court) 20.7 +0.1 28.4 17th 11.2 +0.5 7.1 20th 46.8 45.3 average 103%
St Helens Aerodrome 21.4 +0.3 27.5 17th 12.0 +0.2 6.2 27th 90.6 65.0 high 139%
Swan Island 20.8 +0.3 24.8 17th 14.6 +0.1 10.7 27th 29.4 59.2 average 50%
Swansea (Francis Street) 21.3   28.4 17th 11.2   5.7 31st 48.8
Midlands (district 93)
Ross (The Boulevards) 21.4 -0.5 27.6 7th 8.5 +0.3 2.5 21st 59.0 36.0 high 164%
Southeast (district 94)
Campania (Kincora) 22.0 -0.4 30.2 17th 10.7 +0.6 4.6 6th 44.4 34.3 high 129%
Cape Bruny (Cape Bruny) 18.8 0.0 27.3 17th 12.0 +0.3 7.0 20th 57.2 53.0 average 108%
Cape Bruny Lighthouse 18.2 +0.6 26.8 17th 12.1 +0.9 7.5 20th 67.9 67.8 average 100%
Dennes Point 20.0   29.3 17th 12.8   7.3 21st 53.4
Dover 20.1 +0.7 28.6 17th 9.3 +0.2 3.5 21st 58.6 62.8 average 93%
Dunalley (Stroud Point) 20.7   30.9 17th 12.9   7.9 20th 36.0
Grove (Research Station) 20.8 -0.5 30.0 10th 8.9 +0.8 -0.1 21st 51.0 40.6 high 126%
Hobart (Ellerslie Road) 21.4 +1.3 30.1 17th 12.4 +1.5 7.1 21st 38.6 44.6 average 87%
Hobart Airport 21.1 +0.3 29.8 17th 12.0 +1.2 6.8 20th 55.2 35.9 high 154%
kunanyi (Mount Wellington Pinnacle) 11.0 -0.5 20.1 10th 4.0 -0.1 -1.4 20th 75.8 76.3 average 99%
Maatsuyker Island Lighthouse 16.3 0.0 23.8 17th 11.2 +0.5 6.6 20th 72.8 84.5 average 86%
Melton Mowbray (North Stockman) 20.4 -0.7 28.2 17th 9.1 +0.8 2.0 21st 40.2 32.3 average 124%
Tasman Island 17.0 -0.2 22.7 17th 11.6 +0.2 6.5 20th 57.4 66.0 average 87%
Tunnack Fire Station 19.5 +0.2 25.2 17th     0.5 21st 31.6 47.7 average 66%
Derwent Valley (district 95)
Bushy Park (Bushy Park Estates) 22.0 +0.1 31.0 10th 9.3 +0.8 0.3 21st 26.2 38.9 average 67%
Maydena Post Office 18.7 -1.0 29.5 10th 8.5 +1.3 -0.3 21st 104.9 70.4 high 149%
Ouse Fire Station 21.5 -1.0 31.3 10th 9.2 +1.2 -0.6 21st 39.8 31.1 high 128%
Central Plateau (district 96)
Butlers Gorge 16.1 -0.6 25.8 10th 6.1 +0.9 -3.9 21st 180.0 101.0 v high 178%
Liawenee 15.2 -1.0 21.3 9th 3.3 -0.5 -3.4 21st 89.8 64.8 high 139%
West Coast (district 97)
Cape Sorell 18.6 +0.9 24.1 10th 12.2 +0.6 8.4 21st 80.4 83.2 average 97%
Hartz Mountain (Keoghs Pimple) 14.1 -0.6 25.1 10th 6.1 -0.2 0.9 20th 104.8 71.0 high 148%
Low Rocky Point 18.4   24.9 17th 11.4   4.9 21st 125.6 97.5 high 129%
Scotts Peak Dam 18.2 -0.4 28.5 10th 8.4 -0.1 2.5 21st 184.8 121.4 high 152%
Strahan Aerodrome 19.4 -0.2 25.7 10th 10.2 +0.3 2.2 21st 138.4 105.1 high 132%
Warra 16.5 -0.6 26.4 10th 7.3 -0.2 -1.0 21st 179.2 102.0 high 176%
King Island (district 98)
King Island Airport 20.7 +0.5 28.6 17th 13.3 +1.1 6.3 16th 66.2 51.5 high 129%
Flinders Island (district 99)
Flinders Island Airport 21.5 +0.2 26.6 17th 13.3 +0.7 5.8 6th 35.0 50.1 average 70%
Hogan Island 20.7 +0.2 27.3 17th 14.7 +0.1 9.5 26th 39.2 46.5 average 84%
Note: From 2017, information about Macquarie Island can be found in the climate summary for the Remote Islands and Antarctica

Notes

The Monthly climate summary, generally published on the first working day of each month, lists 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. More extensive discussion of significant weather events, along with later information and data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review.

This statement has been prepared based on information available at 9 am on Tuesday 3 April 2018. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

In some situations, some or all of the rainfall is in the form of hail or snow. In these cases the totals given are for the water equivalent: the depth of liquid water that results from melting any frozen precipitation. There can be significant 'undercatch' of snow in strong winds, meaning the true precipitation can be higher than that reported.

Averages for individual sites 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.

Where temperature area averages are mentioned, they are derived from the ACORN-SAT dataset.

Further information

Media
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