Although the forecast last night was for some showers in the morning, clearing, and most activity expected in eastern Victoria, conditions looked oddly suspicious by mid-morning with plenty of showers through Central Victoria and congesting cumulus by midday, soon followed by a rapidly developing band of thunderstorms extending from Bendigo to Cape Otway.   And the cause was an unexpected low pressure developing around Bordertown in the early morning developing along a north-south trough, which incidentally was the same trough mechanism which brought phenomenal rains to the wheat belt of WA 3-4 days ago.

The development of this low created marked convergence to the east & southeast of the system as it moved southeast across Victoria.  This together with surface heating and orography resulted in 6 hour rainfall totals through Central & North Central Victoria of between 10 & 40mm, resulting in scattered flash flooding in the Melbourne metropolitan area mainly in the west & northeastern suburbs, with heavy falls also extending into West Gippsland.

A nice Australia Day, thank you very much.....
Clyve Herbert

Please note that all times on video stills are AEST *not* AEDST
(please add one hour during daylight savings - ie: now)

Looking west from Mt Dandenong

Interesting things at the base of this cumulus - almost over Andrew's house (non-rotating)

Interesting things at the base of this cumulus (non-rotating)

Looking north west towards Dandenong & Melbourne City from the Dandenong-Hastings Road, Cranbourne in far SE Melbourne

Dandenong Creek at Boronia Road - in 7 years I have never seen it come up this fast - we had 31mm in Bayswater (about 3 kms upstream) within a 6 hour period with most of that falling in an hour or so

Video stills - J ONeill (ASWA archive)