WEATHER TO BE

Ashburton Guardian, Volume 66, Issue 249, 2 August 1946, Page 2

WEATHER TO BE

FORECAST VALUE STRESSED ADDRESS BY RADAR EXPERT Interesting comments on weather forecasting, with particular reference to its possible development, were made by Mr R. W. James, of the radar station staff, in an address at the weekly luncheon of the Ashburton Rotary Club yesterday.

‘‘Weather is a stock subject for conversation,” said Mr James, “and lots of people like to have a dab at seeing into the future as far as it is concerned. The experienced local man will often do as well, in his own locality, as the officials who base their forecasts on reports from all over the country. Many farmers and others, so far as rain is concerned, rely on the old hand whose corns ‘treat 'im somethink crook’” Everybody would realise the value, continued the speaker, if it were possible to forecast what rain would fall during the coming month. Not only would the farmer and gardener know where he stood, bat so also would the storekeeper who was considering whether or not to order extra stocks of goloshes or mackintoshes. Unfortunately, however, they were very little nearer such longrange forecasts today than they were before the war. The main consumers of weather information over the war years, he pointed out, were the airmen of the belli gerent countries. Flying men in wartime required much more specific information than did the farmer; for instance, it was of the greatest importance to know the wind speed at a height of 12,000 feet not only at their base, but also all the way to Berlin the following night. One result of the need for such specific information was that observations had to be made over a vastly wider area than in the ordinary way and also “upstairs” as well, for bombers sometimes had to travel as high as 30,000 feet.

Weather “Recce.” Planes To obtain the required information, special equipment had to be devised and special methods adopted. One of the principal ways used was to send out reconnaissance planes to the required heights and over the particular areas. Right through the war, these weather “recce” flights were frequent, with lone planes winging their way hundreds of miles out over the Atlantic or right along the route which the bombers would follow the succeeding night. Balloons fitted with recording instruments were sent up to heights of 60,000 feet and more. Such investigations naturally involved great increases in expenditure and it was very doubtful whether the authorities would stand for such heavy costs in peace days, especially since, to-day, the tendency was to cut down substantially on meteorological expenses. •

Weather experts, in the ordinary way, continued Mr James, were not quite confident in their forecasts for 12 or IS hours ahead, but anything over three days ahead, say, was regarded as little more than guesswork, rt was his firm view that the aim of the weather services should be to obtain this longrange view. To be able to forecast a month ahead would be invaluable. That had not been ap proached in the past, but hopes could be held out of better results in the future. At the best to-day, all that could be indicated, over a period, was whether the rainfall was likely to be above or below normal.

Radar and the Weather The only way to real improvement, he considered, was to concentrate more on the investigation side of weather. In the past, the experts merely had time to supply such information as was required at the moment, and there was no opportunity for longer range investigation. During the war, for instance, they had to concentrate on other problems, such, for instance, as the effect of weather on radar. Those very short radio waves employed in radar were not known before the war and it was soon found that they were vitally affected by the weather. Thus it came about that radar became a factor in determining weather conditions.

On D-Day, General Eisenhower required detailed information about, the weather over the Channel, because he wished to know how far across the German radar stations would be effective. If their range was all the way, obviously the enemy would have a good idea of the size of the invading fleet, whether or not it was simply a feint attack. It was that sort of question that the Army and Navy were always asking—it was of vital importance to them to know when conditions were right or wrong, for that longrange phenomenon anomalous propagation. Most frequently, this occurred under nor’-westerly conditions, and that was the reason the research station had been established at Ashburton. This was a problem which arose entirely through the war and for war necessities, but it also had an important bearing in peacetime. These ultra-short waves, in the future, would be of vital importance. Mr James answered several questions and, in the course of these replies, pointed out that heavy cloud produced radio echoes, whereas cleai air gave none. At the height of miles or so, however, there was a heavy layer which would deflect waves used in ordinary radios. t On the motion of Rotarian 11. M . Sherratt, a hearty vote of thanks was passed to Mr James. _______