Bureau of Meteorology introduces new weather language

Bureau of Meteorology introduces new weather language

      Updated    10 Oct 2014, 6:40amFri 10 Oct 2014, 6:40am

The Bureau of Meteorology (BoM) is using new terminology to make it clearer for the public to understand rainfall forecasts.

When predicting rain, the BoM will now use a percentage rather than words to describe the chance of daily rainfall.

The forecasts will utilise the new Meteye information system which is helping the Bureau with more exact forecasting across the country.

Senior forecaster Rick Threlfall told 612 ABC Brisbane's Rebecca Levingston that the change is set to make things clearer on the weather front.

"The main change is losing words such as isolated, scattered and widespread," he said.

"Research showed that people weren't sure whether scattered meant more or less rain.

"The forecasts will now deliver direct information, so if there are showers, they will be described in a percentage form."

Mr Threlfall said numbers will make it easier for the public to make daily decisions.

"We needed something that users wanted and people really wanted to know if they were going to get rain and numbers help that," he said.

The daily marine forecast will also change.

"Previously we would only mention things that would affect boating in the waters forecast," said Mr Threlfall.

"Now the coastal waters forecast is exactly what you would get on the land, so it will include sunny or 60 per cent change of rain and it will even explain how much cloud there will be."

New rain terminology


  • 0-10 per cent — no mention of rain in forecast
  • 20-30 per cent — slight chance of rain 
  • 40-60 per cent — medium chance off rain
  • 70-80 per cent — high chance of rain
  • 90-100 per cent — very high chance of rain


How the forecast works

Not only will the public now recieve a percentage when the BoM predicts rainfall but the timing of the rain will also be included.

Mr Threlfall says the new Meteye system places the country into grids to predict the rainfall at a certain point.

Queensland is broken into six-kilometre grids and the Bureau then forecasts rainfall at that particular point.

"If there is more of a chance of a shower in the morning that will be stated and you will get more information on the timing of the showers and they will all be linked in," Mr Threlfall said.

He said the new system will pick up rainfall with 0.2 of millimetre of precipitation," he said..

"That chance of rain on the forecast means the chance of getting any rain at all.

"To work out how much rain you are going to get, you have to look at the rainfall amount section.

"You could be at a high chance of only getting a small amount of rain ... to 0.2mm to be precise."