Where has September rain gone?

ALTHOUGH at face value, spring rain across Victoria appears to have improved in recent years, there are still worrying trends – such as the lack of September rainfall.
Nanjing Night Net

Again, this year’s crops are likely to be limited by a poor September.

Even last year, where crops were thick enough for the proverbial dog to run across, there was a dry patch in September, which experts attributed to the sub-tropical ridge pushing further south than normal.

Although it was lost in all the commotion surrounding the floods later on during harvest, there were early reports that crops were not yielding quite as well as expected upon visual inspection, which was attributed in part to the dry September.

The rainfall figures for September in my rain gauge in Horsham over the past five years are as follows.

2007: 25mm

2008: 23mm

2009: 72.5mm

2010: 39.5mm

2011: 16mm

This compares with a long-term average September rainfall of 46mm, meaning just one year in five has been above average.

But that’s not all – even these figures tell a bit of a fib – with little of the rainfall falling in the crucial middle three weeks of the month.

Here’s the figures from September 5-25 each year.

2007: 14mm

2008:14.5mm

2009: 40mm

2010: 2.5mm

2011: 3.5mm

These figures are firmly in decile1-3 range every year but one.

Much of the September rain either falls very early in the month, when crops in the last three years have been too wet to profit from the rain, or late in the month, when yield potential has been lost.

It may just be a statistical anomaly, but it is a sobering picture in light of projected further falls in crucial spring rainfall.

My records here indicate that winter rainfall is holding relatively strong, there has been at least one significant rain event from November to February, but spring and autumn falls are under pressure.

Let’s hope we start getting rain at the time we want and need it once again!

This story Administrator ready to work first appeared on Nanjing Night Net.

Posted in: 南京夜网