Weather Forecasts

MetraWeather’s ePD forecasting system analyses over a hundred different weather models to extract, combine and place the correct emphasis on the different strengths of the best models - giving you the best possible temperature and wind forecasts

Forecasts for the energy sector have changed. Until a few years ago it was accepted practice to take one weather model and refine and tune its output to achieve the best possible temperature and wind forecasts.

But improvements in individual models have slowed and it is now recognised that there is valuable information to be gained from each of the world’s leading global weather models, in addition to what can be achieved with high resolution models.

It is no longer safe or sensible to rely on the outputs of a single weather model; the best temperature and wind forecasts combine information from multiple models to provide a full range of probability for each variable at the time and place in question.

This is where MetraWeather comes in. Our customers need to know not only what the most likely weather outcome is, but also the potential for any significant variations, based on what is currently known (and unknown) about the current state of the atmosphere.

MetraWeather’s ePD forecasting system analyses over a hundred different weather models using a short time series of historical data and applies cutting edge statistical techniques to extract, combine and place the correct emphasis on the different strengths of the best models.

Every temperature and wind forecast is expressed as a full probability distribution, from which we extract the most likely outcome as well as reliable confidence intervals of all possible outcomes.

Here is a live temperature forecast for tomorrow’s maximum temperature at Heathrow in London to show you what we mean. The mean value of this probability distribution is the most likely outcome and the one that will minimise our forecast error over time, resulting in the greatest forecast accuracy. 

We can also extract a confidence interval and event threshold from the above graph. For example, we have 90 per cent confidence that the maximum temperature will fall between the fifth and ninety-fifth percentiles.

The probabilities from the ePD system have proven reliability, meaning a five per cent probability will come off one-twentieth of the time and a 90 per cent probability will come off nine times out of ten. This allows decision makers to assess the risk of adverse weather events and take action.

The ePD system creates these distributions for temperature and wind out to 15 days in the future. In the graph below for Frankfurt the expected maximum and minimum temperatures are displayed as red and blue dots respectively, while the lines represent the 80 per cent confidence interval around these expected temperatures. Naturally, the confidence intervals become wider the further into the future we look.

a graph of Daily temperature forecasts with confidence ranges.

We can do the same for hourly temperatures and wind speeds, as in the forecast for Heathrow below:

A graph of hourly temperature forecasts and confidence intervals

And we can chop the data up in useful ways to highlight the probability of temperatures or wind speeds reaching critical thresholds. These can be customised for individual users, as in the graphs below.

Sample probability of high winds in Wellington

A bar graph of the probability of the minimum temperature going below threshold values

The math is complicated but the outcome is simple. We forecast the most likely temperature and wind outcomes and the potential for departure from those outcomes. This allows our customers to assess risk and seize opportunities before their competitors, directly resulting in increased profits.

A recent example of the strengths of MetraWeather’s ePD system was a heat wave that struck Adelaide and Melbourne around New Year 2012.

In addition to temperature and wind forecasts from the ePD system, we can also provide forecasts of atmospheric pressure, humidity, cloud cover, precipitation and derivatives such as heating degree days using our own high resolution models out to 72 hours and the world’s best global models from 72 hours out to 15 days.

MetraWeather delivers powerful weather intelligence through its customised weather forecasts. Contact us now to discuss how the ePD system could work for you.

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