June 2012

RAINFALL

What an amazing rainfall month! The whole region received well above average rain, much to the delight of farmers and water managers, but to the horror oflong-range forecasters whose expectations were that the whole region of southern Victoria should return to the drought of the previous decade.

Geelong’s urban area received over double (104 mm) its normal June total (42 mm) and the Bellarine, Golden Plains and Otways areas were also well above.

Most of Geelong’s rain came in two bursts: around the 3rd – 5th, when 60.2 mm fell within 3 days, making it the wettest 3 consecutive June days since 1952! Mt Sabine, at the edge of the West Barwon catchment achieved a record 283 mm at this time; ironically, since then the local rain gauge has malfunctioned and has not yet been repaired. Then again on the 21st – 22nd another 32.6 mm fell in Geelong, much higher in some other places.Weeaproinah recorded the region’s highest monthly total – 337 mm, followed closely by Beech Forest with 322 mm and Lavers Hill with 307 mm.

Both of those rain events were caused by low pressure systems with vigorous cold fronts. On the first occasion it was an”East Coast Low” which slowly retrogressed from the northwest, bringing “wrap-around” rain over Geelong from the south and southeast until it moved away over Tasmania.On the second occasion the system came typically from the west, with several cold fronts tapping in to a much wetter cloud mass propagating from the Indian Ocean. On this occasion the Geelong rainshadow effect was nullified.

TEMPERATURES

Average daily minimum temperature at Breakwater was 6.8 degrees C, and maximums 13.8 degrees C. After the site change is taken into account the temperatures forthe month were slightly lower than Geelong’s average – by 0.5 degrees C.In other words, days were colder than normal and nights were slightly warmer.

OTHER FEATURES

Despite the heavy rain and the colder days, the month was generally settled and only on one day (4th) was there a wind gust over 60 kph.

There were two earthquake tremors experienced in Geelong. The first (Richter 2.3) was felt mainly in the northern suburbs on the 16th. It was centred between Lovely Banks and Anakie near the Rowsley fault. The second (Richter 5.3) originated in Gippsland on the 20th, but no damage was done locally despite the unusual occurrence of 2 tremors within 5 days. There were 2 frosts and the lowest minimum was 0.8 C on the 27th.

RAINFALL DATA