Maleny Weather

The catastrophic Chile earthquake on Sunday 28^th was followed by a Pacific tsunami warning being issued by Hawaiian control centre. The likelihood of a tsunami reaching our coastline was minimal but even so, as a precautionary measure, all east coast beaches were closed, especially to swimmers, surfers and anglers.  However, despite all efforts by police and lifeguards it was difficult to enforce the order to the dismay of authorities and many swimmers and surfers were foolishly waiting for the ‘big one’.

The past week has again been the wet and muggy and we recorded 282mm of rain, with the heaviest falls occurring during the 48 hour period from 9am Monday when a total of 173 mm was measured. It has been an interesting week for meteorologists when three weather systems interacted with one another. The cause for some of our drenching was from a deep monsoonal low in a trough extending across southern Queensland bringing torrential rain and flash floods to the region. Winds were light and movement of the low was slow until Tuesday morning when an east coast low developed close to Fraser Island to intensify rainstorm activity. Winds increased to gale force due to the steep pressure gradient between the high in the Tasman Sea and the ‘east coast low’ off Fraser Island.

On Saturday 6^th March we had another deluge when 109mm fell in a  space of  18hours, causing flash flooding in many areas. The Baroon Pocket dam is full to capacity and closed to both swimmers and boaters.

 Keeping a weather eye open for wind vanes is an interesting pastime. In many countries of the world the tops of buildings are adorned with wind vanes. Weathervane is perhaps not the best word to use, for a vane just indicates wind direction and not weather. The word vane comes from the Anglo-Saxon word ‘fane’ meaning ‘flag’.

In the days of old sailing ships a narrow pennant was flown at the masthead to indicate wind direction to the helmsman and this was known as a vane. Today, sailing yachts use burgees for the same purpose.

The Tower of the Winds in Athens once bore on its roof a wind vane in the form of a bronze Triton holding a a rod in his outstretched hand, rotating as the wind changed direction. Below, the frieze was adorned with the eight deities. The eight metre high structure dates from around 50 BC.

The wind vane evolved from a Triton to a weathercock as the Roman Empire converted to Christianity. Many churches have a weathercock on the tower or spire.

Pope Nicholas 1 in the ninth century ordained all land vanes to be in the shape of a cockerel to remind people of Peter’s denying Christ and the cock- crow that followed. Hence the commonly used synonym weathercocks even when there is no cockerel shown. Weathercocks predominate, however, and can be seen in any shape, form or material. Sometimes in copper sheathed, often gilded, occasionally in lead. The bird’s head always faces into the wind with the tail behind, naturally the larger part, sometimes looking ridiculous.

Vanes in the shape of ships probably follow cockerels in popularity, especially in coastal towns and ports, where fishing trawlers skippers depend so much on the weather that in turn was the will of the wind.

Farms quite often have vanes for the same practical reason, as do the fishing ports. A wind change could mean a change of weather for the good and time to plough or sow.

Rural vanes are often in the shape of a country theme, such as horses ploughing, ridden or pulling some form of transport. Shapes of farm animals and birds are also popular.

Weather, of course, is a major talking point. We keep a weather eye on things, we make heavy weather of other things, and we can be under the weather or weathering life’s storms.

The world’s largest weather vane is JEREZ, Spain. A challenger for the world’s largest weathervane is located alongside Whitehorse International Airport, Yukon. The weathervane is a retired Douglas DC-3 atop a swivelling support. The vane only requires a 5-km/hour wind to rotate.

The term weathervane is also a slang word for a politician who has frequent changes of opinion.

Flash floods happen suddenly (hence the name), forming in less than six hours. This sets them apart from “regular” floods, such as river floods, which can often be predicted days in advance. They are caused when a heavy rain falls over low-lying areas, especially when the soil is already saturated. They happen when rainfall intensity and duration match up, in a very bad way. More than half the fatalities happen when people try to cross flooded intersections in their cars. This is because people are generally not very good at judging the depth and danger of flooded streets. (They can’t actually see the roadway surface, which might be a big deep hole.) While two feet of water doesn’t seem like much at all, especially if you are safely inside a big, heavy car, it is enough to carry you and the car away. (Another fact we tend to forget: cars are buoyant.)  According to the National Oceanic and Atmospheric Administration of USA: –  ”Water weighs 1,010 kg per cubic metre and typically flows downstream at 10 to 20 kph. When a vehicle stalls in the water, the water’s momentum is transferred to the car. For each foot the water rises 226 kg of lateral force are applied to the car. But the biggest factor is buoyancy. For each foot the water rises up the side of the car, the car displaces 2,040 kg of water. In effect, the car weighs 2,040 kg less for each foot the water rises.”

Do not be tempted to drive across a flooded roadway.(”Don’t drown; turn around.”) If you find your vehicle stalled in a flooded road way, leave it and seek higher ground. (”Better wet than dead.”)

The summer season has come to an end. It was a wet one with over 900 mm of rain over the three months. However, it was not as wet as the summer of 2008 when Maleny recorded rainfall of 1,213 mm.

February is usually the wettest month of the year and it is no surprise that it rained on 22 days this month.  Total February rainfall was 601.4 mm, well above the 117 year average of 332 mm.  Previous record rainfall occurred in 2003 with 783 mm. It was also wet in 1999 with 880 mm. This was when 630 mm fell in four days, and brought the Obi-Obi up to the height of the library boardwalk. It also contributed in no small way to the flooding of town centres at Gympie and Maryborough.

Most of the rain we have had this month came from an active monsoonal trough line with a   tendency to track south and interact with a high pressure system extending from a high over the south Tasman Sea..

Mean temperature for the month was up by two degrees from the norm of 20°C, while relative humidity was in the range of 85 and 95 per cent. There were ten days when the THSW Stress factor measured 35°C and over, similar to last year.

The BBC is considering dumping Britain’s Met Office as the public broadcaster’s main weather forecaster and hiring one from New Zealand instead.The state-owned Met Office has come under fire in the past year for its inaccurate long-term forecasts for Britain.It infamously predicted a “barbecue summer” for Britain in 2009 which turned out to be a washout, before incorrectly forecasting a “mild” winter that instead saw the nation blanketed in snow.The BBC has relied on the Met Office for almost 90 years to provide it with forecasts but is now considering switching to New Zealand’s national forecaster, Metra.