August 2010

RAINFALL

Not even the most confirmed atheist has any reason not to give thanks for the region’s great rainfall last month. Heavy August rains have increased catchment totals to over 56% of capacity, having increased by 6% in the last week alone. This is better than at any time since 2005, and has triggered a flood warning on the upper Barwon. For those who study model-based output it was instructive to note the failure of the BoM 3-monthly probability outlook, which predicted only a 30-35% chance of average falls in winter for this region.

The most spectacular result was at Weeaproinah, where 575 mm fell in August, eclipsing the previous total of 472 mm set in 1939, and providing in 4 weeks what Geelong usually takes more than a full year to accumulate. The figures go back to 1901. In this La Nina year this is a significant event. Weeaproinah also broke its all time monthly record of 538 mm set in June 1952.

Winter rains compared to average: Weeaproinah 899 (674 mm average), West Barwon Dam 432 (410 mm), Apollo Bay 433 (351 mm), Aireys Inlet 233 (221 mm), Geelong Airport – Mt Duneed 148 (140 mm), Waurn Ponds 153 (134 mm), Bell Post Hill 167 (144 mm), Barwon Heads 216 (179 mm), Leopold 198 (160 mm), Bellbrae 220 (184 mm), Lara 100 (115mm) and Anakie 144 (144 mm).

Some areas to our northwest, from Lara to Anakie and the Moorabool catchment were not quite as fortunate over winter, but their August rainfalls were generally above average.

TEMPERATURES

It was Geelong’s coldest winter since 1998 and its 2nd coldest in 19 years of Airport figures at Mt Duneed. Mean daily winter temperature this year was 9.6 degrees C, and the long-term daily mean is 10.1 degrees C. All 3 winter months were colder than average, June by 0.5C, July by 0.2C and August by 0.85C.

August was nearly a full degree colder than average. Daily maximums averaged 13.5 degrees and minimums averaged 5.6 degrees. These figures are 1.5 and 0.2 degrees below the means of 15.0 and 5.8 degrees respectively established at Geelong Airport 1992-2009. Average daily temperature last month therefore was 0.85 degree below normal.

Coldest overnight temperature was 2.2 degrees C on the 7th, and the warmest day reached 17.7 degrees C on the 30th.

OTHER FEATURES

There were 9 days where wind gusts exceeded 60 kph, including speeds of 76 kph recorded at Mt Duneed on both the 24th and 25th. On 2 occasions small hail fell, but there were no severe storms. One thunder day occurred without incident.

RAINFALL DATA

 

GEELONG REGION
Location Total for
Month
(mm)
Monthly
Average
(mm)
Aireys Inlet 115.0 78.5
Anakie (Granite Road) 61.0 46.0
Anakie (De Motts Road) 73.2 46.0
Anglesea na 69.0
Apollo Bay 292.4 124.7
Bacchus Marsh 66.8 39.0
Ballan 119.2 55.6
Ballarat 161.0 76.4
Bannockburn 68.2 47.0
Barwon Heads 96.8 63.0
Bells Beach na 60.4
Bellbrae 98.0 60.4
Beeac 122.4 70.1
Benwerrin 189.8 164.0
Birregurra 142.0 80.3
Boonah 175.0 150.0
Cape Otway 221.0 102.1
Colac 164.2 59.5
Clifton Springs 86.6 52.0
Cressy 106.4 52.0
Curlewis 70.0 42.0
Dereel 131.7 62.0
Drysdale na 54.9
Durdidwarrah 89.0 53.3
Forrest 264.6 146.2
Forrest (West Barwon) 251.0 146.2
Gellibrand na 103.2
Inverleigh 67.0 na
Johanna Heights 380.0 na
Lal Lal 125.8 na
Lavers Hill 505.0 na
Laverton 63.6 48.0
Little River West 57.0 38.0
Melba Gully na n.a.
Melbourne (City) 63.0 51.0
Meredith (Darra) 79.0 61.7
Moriac 101.0 58.0
Morrisons 93.8 80.3
Mt Cowley 267.0 185.0
Mt Mercer 106.0 70.3
Mt Sabine 335.0 210.0
Ocean Grove na 45.0
Pollocksford 69.2 n.a.
Point Lonsdale 87.4 59.0
Queenscliff na 61.4
Scotsburn 112.0 80.3
Shelford na 51.0
Sheoaks 77.4 47.0
Skipton 133.4 48.0
St Leonards na 60.0
Teesdale na 44.5
Torquay 125.0 64.0
Warncoort na 89.8
Weeaproinah 575.0 232.8
Winchelsea 104.6 57.2
Wooloomanatta 59.0 47.2

GEELONG SUBURBS
Location Total for
Month
(mm)
Monthly
Average
(mm)
Avalon 65.0 48.3
Bell Park 83.1 50.9
Belmont 90.5 49.4
City 66.0 51.0
Connewarre 73.1 44.3
Corio 69.8 42.0
East Geelong 76.1 47.3
Grovedale 93.0 51.5
Hamlyn Heights 69.0 46.0
Highton 83.0 51.5
Lara 60.0 39.6
Lara (Serendip) na 39.6
Leopold 79.0 49.5
Leopold East 82.0 49.5
Manifold Heights 76.4 46.0
Moolap 71.0 45.0
Mt Duneed Airport 70.8 48.1
Mt Duneed West 103.8 48.1
Waurn Ponds 71.6 48.1
Whittington na 51.0
Urban Area Average 78.0 47.3