Weatherforecasts forecast.

From The New York Times. Published August 25 1901.
A PDF. …


“There is more bald-faced faking done in this business than in any other.” So spake the Weather Man. He was just beginning to puzzle himself over the incipient hurricane in the Lesser Antilles last week and to wonder whether it would reach New York.

The storm might reach the Atlantic seaboard within a day or so, or it might not.

The Weather Man, with all the science of meteorology at his command, with all the experience of the thirty years history of the Weather Bureaux ready for his reference, couldn't tell just what this storm would do during the next forty eight hours of its career. Hence he seemed a little exasperated that weather “prophets" with no science to hold them up, with no elaborate records to guide them should presume to foretell months in advance just what the snow, the wind and the rain should do.

“Do you suppose that if these fellows really knew anything about weather, that the bureau would allow them to work independently of it for a day?” he queried.

"A man who can accurately foretell the state of the weather for two months hence can get his own price from the United States Government. Struggle as we may, we can't predict with accuracy for more than thirty-six hours ahead and we have at our beck and call all the science that observation of years has been able to accumulate.

As a matter of fact there is no scientific possibility of foretelling what the weather will do more than two or three days beforehand. Upon what these charlatans base their predictions, it is impossible to state. They may base them upon the phases of the moon.

Perhaps this is not so far wrong, apparently, because the moon's phases change every seven days and this is just about the period of storm recurrence. There is no possible connection between the two; it is simply a coincidence.

Some of the charlatans claim that they obtain insight into the future weather conditions from the sun spots, which become frequent upon the solar surface about every eleven years.

It is true that there is a relation between sunspots and magnetic conditions of the earth but no relationship has as yet been scientifically established between the weather and magnetic conditions on this planet.

As for the stars, they have no possible connections with meteorological conditions here and it is the merest folly to presume to base any weather prediction upon their changes and movement. Stars have no more connection with the climate than they have with the every-day occurrences in the lives of men and women.

The United States Weather Bureau takes observations every day at stations ranging from Edmonton, in the Canadian Province of Alberta, on the north-west; St. John's Newfoundland, on the north-east; the island of Barbados on the south-east and Acapulco, on the south-west.

The observations of temperature, barometric pressure and rainfall are all reported twice every day from each of these stations to the central stations of the bureau and upon the basis of these observations, forecasts are made. (Which of course, were forwarded by telegraphic despatches having the right of way above everything else.)

The weather forecaster at a central station takes the observations and makes up a. weather chart. On this chart he records the places where the barometric pressure is the same and then lines (curves, called isobars) are drawn through these points.

It will be found that there are certain areas of the country where the barometric pressure is low, the lowest point being the centre of the uneven circular figure made by the isobars. Adjacent to this low-pressure area will be a high-pressure area, likewise indicated on the weather chart by isobars.

The meaning of the expression "low pressure" is that the air in this area is not so heavy comparatively as it is in the high-pressure area; there is not such a. pressure upon the earth.

The tendency of the high-pressure areas, therefore, will be to divert their heavy air to the place where the pressure is not so great. This by an obvious law of mechanics. This movement of the air is what causes winds. The forecaster can foretell that the low pressure area. is to be affected by the winds from the high-pressure area.

The forecaster knows too, that high and low pressure areas drift across the country from the west toward the east at the rate of about 600 miles daily; that the "highs"are attended by dry, clear and cooler weather and that they are drawing down, by a vortice action of their centres, the cold air from great altitudes above the clouds and causing it to flow away laterally along the surface of the earth.

The "cold wave” comes when the high-pressure areas become so intense in their vortice action that they draw down an unusual quantity of cold air.

The forecaster knows, also from years of observation, that the "low pressure" areas are generally accompanied by rainy and warmer weather, and that the " high pressure " and "low pressure" areas follow each other across the country at average intervals of about three days.

The study of the weather map each day, coupled with the knowledge of past experience, enables the forecaster to tell, with reasonable accuracy, what will happen in any given district within the next forty-eight hours, No attempt is made to make definite predictions covering a period of more than thirty six hours."

The Weather Man then proceeded to show how the Weather Bureau of the United States Government really conducted its business. He said that meteorology must not he understood to be an exact science. A man's experience and judgement are very material factors in determining his capabilities as a weather forecaster. He has to make a. careful study of conditions and base his predictions upon them.

“And these facts you may take as assured." he said. “The first is that we never fail to give·warning of coming storms. Sometimes we may think a storm is coming when it doesn't materialise. But it is much better to take heed against a storm that doesn't come than to be caught in one that does come.

Millions upon millions of dollars have been saved from destruction on the seas since the United.States Weather Bureau began sending out its storm signals. The second important fact, which the layman seems to take little notice of, is that the Weather Bureau cares very little whether it rains or not.

“It is impossible to accurately foretell showers. They make very little difference to business or agriculture, anyway. Showers generally benefit crops and they do not disturb trade. We have more responsible business to look out for than to guarantee that the women who venture out on a certain day do not get their feet wet”

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