Advancing forecasts

Perhaps some of you wondered why

Perhaps some of you wondered why. A few who read Weather Eye on Saturday, and noticed that it came from several hundred miles inside the Arctic Circle, may have wondered, en passant, what brought the doyen of page 2 to such latitudinal extremes. Most, no doubt, did not. But I propose to tell you anyway.

It all goes back to 1976 or thereabouts, when a perception emerged among European meteorologists that little progress was being made in improving forecasts for extended periods.

Short-range forecasting was progressing nicely, and becoming more accurate with every year that passed, but when it came to more than a day or two ahead, existing computer models of the atmosphere were quite inadequate.

In any case, individual meteorological services did not have computers big enough to cope with the massive calculations that predictions for several days ahead require.

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The problem was solved by pooling resources. Eighteen nations came together to form the European Centre for Medium Range Weather Forecasts, or ECMWF as weather-people call it.

The centre is staffed by leading meteorologists from all over Europe, and also maintains one of the largest computer installations in the world to process the mathematical models that predict our future weather. ECMWF, based in Reading in the south of England, is now the world leader in the preparation of forecasts for two to 10 days ahead.

Every 24 hours, the centre transmits to each of the 18 member-states detailed charts showing how the global pressure pattern is likely to develop during the following 10 days. With the aid of these charts, meteorologists in each recipient country are able to provide extended forecasts with much more accuracy than if they had to depend upon their own resources.

Indeed for smaller countries like Ireland, it would be almost impossible to attempt extended forecasting at all without this guidance.

Now the affairs of ECMWF are governed by a council headed by a president, the latter normally being the director of the meteorological service of one of the member-states, and holding office for a term of four years.

It has become a tradition that towards the end of his period in office, the President holds one of the bi-annual council meetings, not in Reading as is usual, but at a location of his choice in his own country. For the last four years the president of ECMWF has been Dr Arne Grammeltvedt of Norway, and he exercised his privilege by inviting council to meet in the novel surroundings of the most northerly city of that country.

And that is the reason Weather Eye repaired to Tromso.