Victoria's recent rain event - 29/3/2008
Could the recent rain event in Victoria be called 'The Autumn Break" which has been largely missing in recent years?
The Autumn break is usually defined as the first rain event after summer in which a good solid soaking rain event occurs. Usually this should occur in March or April. It should be accompanied with good general soaking rains across a wide area.
Looking at the rainfall records for the past week for Victoria from the BOM rainfall statistics from numerous rain gauges around the state, it will depend on the locality. Some areas recorded reasonable falls but other areas received minimal falls.
I noted that the upland areas of NE Victoria received some good falls due to orographic effect but the agricultural regions away from the hills received low totals, too low to have an impact on water supplies.
It is interesting to see how Melbourne fared. The north eastern suburbs and even the city received good falls but the NW and west and parts of the southern city areas did not. Some sample tallies for Melbourne for the 7 days from Saturday 22 March to Saturday 29 March include:-
Melbourne City 64 mm, Prahran 82 mm, Melbourne Airport 18 mm (Located NW), Altona 36 mm, Rosebud 18 mm, Scoresby 9 mm, Morabbin 23 mm.
The variations are large and the Dandenong Ranges to the east did influence totals that fell.
This was the picture right across the state of Victoria during the same period as shown in the samples below.
NW Victoria
Mildura 12 mm, Ouyen 3 mm, Redcliffs 17 mm.
Mallee
Falls of 0.6 mm to 23 mm featured.
North Wimmera
Falls of 0.2 to 22 mm featured.
South Wimmera
Some very good falls fell including Ben Nevis 37 mm and Stawell 44 mm.
Lower North
Rains were mostly poor or lighter such as Echuca 6 mm, Kerang 28 mm, Boort 13 mm. This was common throughout.
Upper north.
Rains were mostly light to moderate such as Bendigo 12 mm and nearby Lake Eppalock 8 mm, Shepparton 25 mm, Tatura 15 mm, Yarrawonga 23 mm.
Similar falls occurred in the surrounding agricultural lands and wheatbelt.
North east.
Similar to upper north for the lowlands such as the Albury region, 26 mm but centres closer to the NE ranges did well due to orographic influences such as Corryong 50 mm, Euroa 27 mm, Tallangatta 29 mm, Dartmouth 41 mm, bright 34 mm and Mt Buffalo 48 mm.
Gippsland
Falls ranged from light to very good, anywhere between 6 and 46 mm.
Some places did well and the event could be called the Autumn break but in many others, the recent event could not be called that. The sample provided shows that rainfalls were patchy throughout the state ranging from very good to poor. Given that many centres in northern Victoria went without rain for up to 40 days until this week, the recent event would have made little impression on the dry gripping the state in some regions.
Harley Pearman
