An Open Letter to the @cityofmelbourne: Why Is Our City so Bipolar?
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I’ve been meaning to write this letter for a long time now. But my love for Melbourne has convinced me not to. Her sunny days and autumn evenings have given me many memorable marshmallow sunsets.
But Melbourne, my love, you have pushed me too far. You’ve played with my emotions. I can no longer forgive you for your Bipolar Nature.
How is it possible for you to smile so brightly at noon, and then suddenly rain without any warning, as I cycle back home?
I arrived home soaked in the sudden rain. My leather boots turned into weather-ruined boots. I was fuming.
Melbourne’s Cold Temperature
What frustrates me most is that weather reports never seem to be accurate. A forecast of 15°C causes me to believe that a hoodie and a pair of jeans are enough – only to find out that it’s actually more like 5°C and I’m shivering as I cycle to class.
There are actually two types of weather forecasts. The commonly referred to “Temperature” is what the actual temperature is. The “Feels-Like” temperature takes into account of other things in the environment, like the effect of the gushing winds that blow against our face. This is what you should be aware of if you want to know what to wear.
On an average Melbourne day, the temperature of what it feels like (in orange) is consistently lower than the actual temperature (in blue). Now you know, don’t be fooled: look at the “Feels-Like” temperature instead.
But Melbourne’s cold is nothing when compared to how it can have “Four Seasons in a Day”. The turbulent changes that occur within an hour can drive you nuts!
This is a result of Melbourne’s unique geographical position. On the map, we are roughly 37° South of the Equator. 37° North or South of the equator are where many other cities lie like Buenos Aires, Madrid, Rome and Washington DC. However, these cities are not known for their turbulent weather, but Melbourne is. This must mean that there are other factors that cause Melbourne’s bipolar nature – which is unrelated to her location from the equator.
Melbourne’s Fickle Weather
So why does Melbourne get special treatment? Why is her weather so fickle?
If you look at the bottom of the map, you’ll see that there is nothing but water separating Australia and Antarctica. Air from Antarctica is free to blow in unhindered, giving us chilly breezes all year long.
Below is another map of Australia, using colours to show the elevation of the land. Land in green is below 200m, yellow is around 600m and brown is 1000+m.
You’ll see immediately that there is plain of green spanning from the top to the bottom (slightly to the right of centre). On the West are yellow/brown mountains, and on the East near the coast in brown are the mountains that form the Great Dividing Range. The hot desert wind from Central Australia is channeled through this pathway. The mountains on each side act as walls that concentrate the flow of wind, such that they all blow either towards or away from Melbourne. When they do blow towards Melbourne, we get those unbearable heat waves of 40°C+.
This is where Melbourne’s unique geographical position comes into play. Melbourne is where the paths of the cold Antarctica air and hot desert air intersect. Even meteorologists find it difficult in predicting what’s coming next.
When opposites meet, something bad is bound to happen. When good meets evil, all hell breaks loose. When warm and cold air meet, we get those famous 5-minute Melbourne Showers™.
These showers are the result of two basic science concepts:
(1) We know that warm air is less dense than cold air because it expands. This is the reason why hot air balloons rise.
(2) Water droplets are formed by a process called condensation. Water vapour cools into droplets which accumulate to form clouds.
In Melbourne, as the cold air meets the warm air, the warm air will start to rise because it is less dense. As it rises, the cold air cools the warm air into droplets. These droplets accumulate into clouds until they start to rain.
Melbourne may be the world’s most livable city, but living here comes at the cost of unpredictable weather. You can get spells of picturesque sunsets but be prepared to be sprinkled with short periods of rain.
Unfortunately, there’s nothing much we can do. Melbourne’s geographical location situated in the middle of two sources of opposing winds is the key reason to her Bipolar nature. Unless you can move mountains and block off the path of the wind, there really isn’t much you can do to stop these winds from interacting.
Just make sure you have a rain jacket with you where ever you go and you’ll be on your way of becoming a fine Melbournian.
One of my aims of these blogs is to inspire curiosity. We are all naturally curious, in fact all of these posts are questions that my friends have asked me to explain.
Shout out to John Raj for suggesting this topic. If you have any ideas, please comment them below!