March 2010

RAINFALL

Large areas of the Geelong region have received around double the average March rainfall. Southern Geelong recorded well over 60mm for the month compared to the average 30.2mm. This result means that, after a poor start to the year, February and March have received above average falls so that our 3-monthlyaccumulated figure (108mm) is running 15% higher than normal. The northern suburbs did not fare as well with only 40-50mm for the month, although NorthernLara, Anakie, Sheoaks and Bannockburn all received 70-80mm.

This is a generally good result for local gardens and rural dams as well as for the Otway catchment. The West Barwon Dam received approximately72mm for the month (average 63mm) and its accumulated total for the 3 months is about 140% of normal. At this time of year however, levels do not riseunless the catchment floor is very damp, and this has not occurred as yet, so the capacity figure remains about 30%. The famous Weeaproinah is also well above average for the January to March period. Most of Geelong’s rain occurred between the 5th and the 9th, when severe storms swept the district (see below).

TEMPERATURE

March temperatures were about 1.0 degree warmer at Geelong Airport than the averages for the period 1992-2009. Average daily maximum temperature was 24.5 degrees compared to the normal 23.2, and minimums averaged 13.2 degrees compared to 12.4. There were 5 days over 30 degrees with the maximum reaching 33.9C on the 4th. Daily relative humidities were comparatively high for March. As far as temperature trends are concerned, the last 19 years on record from Geelong Airport shows a fractional linear rise of 0.11 of a degree.If extrapolated to the year 2100 – a very risky thing to do although climatologists love to do it – it would indicate a rise of about half a degreeby then, in other words, no excessive warming in March in Geelong in the 21st century! But such a conclusion is practically worthless because therecords of just one month are only one-twelfth of the total data required to make such a projection. As well, a current trend in temperature is no guarantee of continuation for a number of important reasons. In fact, several prominent researchers are predicting global temperatures, including Australia’s, are very likely to decline over the next few years, thus opposing the current political line being pushed by CSIRO and BoM.

OTHER FEATURES

A severe storm (the first for the year) on the early morning of the 5th saw local flash flooding, especially in southern suburbs when 25mm in one hour was recorded in the Grovedale – Mt Duneed – Torquay areas as well as the Anakie district where up to 75mm fell within a couple of hours. Some damage resulted, but not as much as the associated storms caused in Melbourne. For 3 days in succession, the 6th, 7th and 8th, thunder and lightning occurred in Geelong. There were 4 thunder days in total.Otherwise it was a relatively calm month as there were only 2 strong wind days (maximum gust 63 kph on the 9th).

RAINFALL DATA