September 2009

RAINFALL

For the third month in a row Geelong and the surrounding region has had above average rain. Urban Geelong averaged over 60 mm on 16 days in September (wettest September since 2005) and the West Barwon Dam received 114 mm. Even most areas to the northwest such as Avalon, Anakie and Sheoaks reported above average falls.

This is a good result, in contrast with the pessimistic three-month outlook by the Bureau of Meteorology model, which predicted only around a 35-40% chance of the region receiving average rain. The wet start to spring has meant well above average totals over the last three months: Geelong recorded 118% of normal July to September rains, Lara 100%, Moriac 133%, Moolap 128%, Avalon 106%, Sheoaks 104%, Aireys Inlet 116%, West Barwon 114%, Apollo Bay 139% and Weeaproinah 118%.

Geelong’s water catchments are now at 33.7% capacity, higher than at any time in the last 12 months.

After a very dry summer-autumn our 2009 totals to date are now up to 75% of “normal” for this time of year. This is a pleasing recovery and places us in the 2nd decile of all January to September falls, only our 17th driest similar period since 1871.

The outlook for October of some independent forecasters continues to be optimistic. There has been an observed shift in atmospheric long-wave patterns according to Clyve Herbert, head of Aussky and GWS associate. Clyve’s understanding and success in interpreting subtle upper level tropospheric variations means he is confident of reasonably good rainfall for this region (within the average range) for October. Ian Holton, independent weather forecaster of Adelaide, also believes southeastern Australia is on the verge of increasing growing season rainfall. We sincerely hope and pray they are right.

TEMPERATURE

September in Geelong was slightly (0.45C) warmer than the long-term average. Daily minimums averaged 6.8C compared to the mean 6.6C, and daily maximums averaged 17.2C compared to 16.5C. The warmest day (12th) reached 29.1C and by way of contrast the coldest overnight temperature was 1.5C on the 15th. The warmest overnight temperature was 12.9C on the 13th and the coldest day was the 27th (Grand Final day) when cold southwesterlies from a low south of Tasmania kept the maximum to just 11.6C.

If official Bureau figures show Australia was much hotter in September, it is obvious that the trend was not evident to the same extent in this region.

OTHER FEATURES

There was one frost (15th) and one thunder day with lightning (21st). Despite the lack of storm days a funnel cloud was observed at Lara on the 7th. Strong winds gusting over 60kph were experienced on 9 days, with maximum gusts of 76kph at Mt Duneed on the 4th and 13th.

RAINFALL DATA

 

GEELONG REGION
Location Total for
Month
(mm)
Monthly
Average
(mm)
Aireys Inlet 79.2 (71.9)
Anakie 68.4 (64.0)
Anglesea na (70.5)
Apollo Bay 96.4 (108.6)
Ballan 93.8 (51.5)
Ballarat 89.4 (73.0)
Bannockburn 73.4 (52.0)
Barwon Heads 70.6 (61.0)
Bellbrae na (60.5)
Bells Beach na (60.5)
Beeac 62.1 (59.9)
Boonah 101.8 (n.a.)
Benwerrin 122.4 (n.a.)
Birregurra 88.8 (69.6)
Buninyong 84.0 (n.a.)
Clifton Springs 82.0 (65.0)
Cape Otway 107.2 (89.6)
Colac 73.4 (68.0)
Cressy 76.4 (n.a.)
Curlewis na (68.6)
Durdidwarrah 65.4 (69.9)
Forrest 109.4 (118.0)
Forrest (West Barwon) 114.0 (118.0)
Gellibrand na (n.a.)
Inverleigh 45.0 (51.6)
Johanna Heights 151.0 (170.0)
Lal Lal 59.6 (82.0)
Lavers Hill na (180.0)
Laverton 58.8 (53.0)
Melba Gully na (n.a.)
Melbourne (City) 67.4 (59.4)
Meredith (Darra) 61.2 (70.4)
Moriac na (56.0)
Morrisons 76.6 (n.a.)
Mt Cowley 149.4 (n.a.)
Mt Mercer na (n.a.)
Mt Sabine 139.4 (n.a.)
Ocean Grove na (n.a.)
Point Lonsdale 85.0 (59.2)
Pollocksford 58.4 (n.a.)
Portarlington na (59.2)
Queenscliff na (59.2)
Shelford na (54.6)
Sheoaks 64.4 (n.a.)
Skipton 49.8 (n.a.)
St Leonards na (58.0)
Teesdale na (57.7)
Torquay 68.5 (58.0)
Warncoort na (n.a.)
Weeaproinah 199.8 (200.3)
Winchelsea na (54.4)
You Yangs na (46.0)

GEELONG SUBURBS
Location Total for
Month
(mm)
Monthly
Average
(mm)
Avalon 70.6 (46.7)
Belmont na (50.2)
Bell Park 65.1 (50.0)
City 58.0 (48.2)
Connewarre na (60.3)
Corio 73.5 (46.6)
Grovedale 66.0 (51.0)
Grovedale South 68.2 (51.0)
Hamlyn Heights (1) 62.0 (51.9)
Hamlyn Heights (2) na (51.8)
Lara 61.5 (47.5)
Lara (Serendip) 73.8 (47.5)
Leopold na (50.8)
Leopold East na (50.8)
Manifold Heights na (51.9)
Moolap 60.4 (52.0)
Mt Duneed Airport 54.0 (51.0)
Mt Duneed West na (51.0)
Waurn Ponds 59.6 (51.0)
Whittington na (50.3)
Urban Area Average 62.0 (48.0)