Thursday, 1 April 2010 - Monthly Climate Summary for Melbourne Metropolitan Area and Environs - Product code IDCKGC2xx0

Melbourne Metropolitan Area and Environs in March 2010: Rainfall much more than that usually received.

The city of Melbourne's total rainfall for the month was 79 mm, this being much more than that usually recorded (normal 50.4 mm, percentage of normal received during the past month 157%).

Overnight minimum temperatures were much warmer than those historically experienced and averaged 16.3°C (departure from normal 3.1°C), partly on account of the heat island effect (cities are usually warmer than their rural surroundings, especially at night, because of heat stored in bricks and concrete and trapped between close-packed buildings).

Daytime maximum temperatures were also much warmer than those usually experienced and averaged 26.2°C (departure from normal 2.3°C).

The maximum temperature in the city has now reached  20°C on every day since 9 December last year (113 days), the longest string of 20°C+ days on record (previous record: 78 days, set between 29 December 2000 and 16 March 2001).

On 6 March, a developing low pressure system with an associated low pressure trough to the west of Victoria generated showers and thunderstorms in the west of the State during the morning, which spread eastward and intensified during the early afternoon. Severe thunderstorms developed to the northwest of the Melbourne Metropolitan Area and moved through the city from early afternoon progressing to the eastern suburbs and then into West Gippsland later in the afternoon.

The severe thunderstorms were associated with large hail and heavy rain resulting in widespread flash flooding and water and hail damage to property. Hail of 10cm was reported at 3.30 pm at Ferntree Gully, with 7cm hail at 3:30pm Ferny Creek, and 5cm hail at Blackburn and Glen Iris. Historically, the only comparable report of such large hail in Melbourne was from 14 November 1901 when "an egg shaped mass of ice (was) picked up in Victoria Parade (that) had dimensions 7 cm x 4.5 cm x 4 cm."

 Details Extremes Records Summaries Important notes the top

Selected Melbourne suburbs

In the suburb of Essendon, which is located some 15 kilometres to the northwest of the city centre, overnight minimum temperatures were much warmer than those usually experienced and averaged 14.6°C (departure from normal 2.3°C). Daytime maximum temperatures were warmer than those usually experienced and averaged 25.2°C (departure from normal 1.3°C). Total rainfall for the month was 82 mm, this being much more than that usually recorded (normal 39.9 mm, percentage of normal received during the past month 206%).

The suburb of Laverton is located some 30 kilometres to the southwest of the city centre, and is often under the drying influence of the rain shadow from the ranges of western Victoria. Here, overnight minimum temperatures were much warmer than those usually experienced and averaged 14.6°C (departure from normal 2.1°C). Daytime maximum temperatures were much warmer than those usually experienced and averaged 25.2°C (departure from normal 1.6°C). Total rainfall for the month was 70.8 mm, this being much more than that usually recorded (normal 35.6 mm, percentage of normal received during the past month 199%).

In the suburb of Bundoora, which is located some 20 kilometres to the northeast of the city centre, overnight minimum temperatures were much warmer than those usually experienced and averaged 14.4°C (departure from normal 2.1°C). Daytime maximum temperatures were warmer than those usually experienced and averaged 25.6°C (departure from normal 1.4°C). Total rainfall for the month was 76.2 mm, this being much more than that usually recorded (normal 44.5 mm, percentage of normal received during the past month 171%).

In the suburb of Moorabbin, which is located some 20 kilometres to the southeast of the city centre, overnight minimum temperatures were much warmer than those usually experienced and averaged 14.5°C (departure from normal 1.7°C). Daytime maximum temperatures were warmer than those usually experienced and averaged 24.9°C (departure from normal 1.2°C). Total rainfall for the month was 58.4 mm, this being slightly more than that usually recorded (normal 44.8 mm, percentage of normal received during the past month 130%).

Synoptic summary

The generally warmer than normal conditions were associated with extended periods of northerly flow across eastern Australia, because of the tendency for high pressure systems to be located over the Tasman Sea, where Mean Sea Level pressures averaged more than 4 hPa above the long term average.

The generally wetter than normal conditions may be linked to the frequent incursions of moisture brought by ex-tropical cyclones, which were steered over inland Queensland by the easterly flow on the northern flank of the Tasman Sea anticyclones.

Mean Sea Level pressures were well above normal over Victoria for much of the month. Melbourne's reading of 1037.6 hPa at 9.53am on the 12th was the highest on record for March. 

Rainfall

Some sites had their highest total March rainfall for at least 10 years.

Temperature

Some sites had their highest March mean daily minimum temperature on record.

Some sites had their highest March mean daily minimum temperature for at least 10 years.

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Extremes in March 2010
Hottest day	34.2 °C at Laverton RAAF on the 17th
Warmest days on average	26.2 °C at Melbourne Regional Office
Coolest days on average	21.0 °C at Ferny Creek (Dunns Hill)
Coldest day	13.2 °C at Ferny Creek (Dunns Hill) on the 10th
Coldest night	4.9 °C at Coldstream on the 2nd
Coolest nights on average	11.8 °C at Coldstream
Warmest nights on average	16.3 °C at Melbourne Regional Office
Warmest night	23.0 °C at Melbourne Regional Office on the 19th
Wettest overall	86.2 mm at Melbourne Airport
Driest overall	46.4 mm at Avalon Airport
Wettest day	46.4 mm at Melbourne Airport on the 7th
Highest wind gust	102 km/h at Melbourne Airport on the 6th

Details Extremes Records Summaries Important notes the top

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Highest total March rainfall for at least 10 years
	Total rainfall for March 2010 (mm)	Most recent higher for March		Years since higher	Average for March
Essendon Airport	82.0	154.1	in 1970	24	39.9
Bundoora (Latrobe University)	76.2	99.4	in 1999	11	44.5
Coldstream	82.4	124.8	in 1999	11	48.0

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Record highest March mean daily minimum temperature
	Mean daily minimum temperature for March 2010 (°C)	Previous highest for March		Years of record	Average for March
Essendon Airport	14.6	14.5	in 1956	40	12.3
Coldstream	11.8	10.8	in 2000	15	9.2
Viewbank (ARPANSA)	14.2	13.2	in 2007	10	12.4

Highest March mean daily minimum temperature for at least 10 years
	Mean daily minimum temperature for March 2010 (°C)	Most recent higher for March		Years since higher	Average for March
Laverton RAAF	14.6	15.3	in 1974	36	12.5
Melbourne Regional Office	16.3	16.8	in 1974	36	13.2
Bundoora (Latrobe University)	14.4	14.5	in 1983	23	12.3
Cerberus	13.9	14.1	in 1992	18	12.3
Cranbourne Botanic Gardens	13.4	13.9	in 1992	18	12.3
Melbourne Airport	14.4	14.4	in 1992	18	12.6
Moorabbin Airport	14.5	14.5	in 1992	18	12.8
Scoresby Research Institute	13.9	14.4	in 1992	16	12.4
Avalon Airport	13.8	13.9	in 2000	10	12.2
Ferny Creek (Dunns Hill)	12.6	12.7	in 2000	10	11.1

Details Extremes Records Summaries Important notes the top

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Summary statistics for March 2010
	Maximum temperatures for March (°C)				Minimum temperatures for March (°C)				Rainfall for March (millimetres)
	Mean for March 2010	Diff from average	Highest for March 2010		Mean for March 2010	Diff from average	Lowest for March 2010		Total for March 2010	Average for March	Rank of March 2010	Fraction of March average
Avalon Airport	25.1	+1.0	34.1	4th	13.8	+1.6	8.9	23rd	46.4	28.7	high	162%
Bundoora (Latrobe University)	25.6	+1.4	33.2	17th	14.4	+2.1	9.1	12th	76.2	44.5	high	171%
Cerberus	24.3	+1.5	32.7	4th	13.9	+1.6	8.7	14th	62.0	45.3	average	137%
Coldstream	26.1	+1.0	32.2	18th	11.8	+2.6	4.9	2nd	82.4	48.0	high	172%
Cranbourne Botanic Gardens	24.8	+1.4	32.5	17th	13.4	+1.1	9.0	12th	66.5	41.2	high	161%
Essendon Airport	25.2	+1.3	33.5	17th	14.6	+2.3	10.1	12th	82.0	39.9	v high	206%
Ferny Creek (Dunns Hill)	21.0	+1.1	27.4	17th	12.6	+1.5	6.9	1st
Laverton RAAF	25.2	+1.6	34.2	17th	14.6	+2.1	8.5	22nd	70.8	35.6	high	199%
Melbourne Airport	25.0	+1.0	32.5	17th	14.4	+1.8	9.1	31st	86.2	37.3	v high	231%
Melbourne Regional Office	26.2	+2.3	33.0	17th	16.3	+3.1	11.1	12th	79.0	50.4	high	157%
Moorabbin Airport	24.9	+1.2	33.1	17th	14.5	+1.7	8.7	12th	58.4	44.8	high	130%
Scoresby Research Institute	25.4	+1.4	32.0	17th	13.9	+1.5	6.8	11th	86.0	53.9	high	160%
Viewbank (ARPANSA)	26.0	+0.7	32.8	17th	14.2	+1.8	8.4	12th	70.0	41.6	high	168%

Details Extremes Records Summaries Important notes the top

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