Science: Weather Analysis

Air-mass analysis is the biggest thing in modern weather forecasting. Weather is a three-dimensional phenomenon, so instead of confining itself to surface observations, air-mass analysis gets off the ground. Its practitioners take temperature, pressure and humidity recordings in the upper air, so that they can study the movements and interactions of tropical masses (warm, wet) and polar masses (cold, dry)—gliding, tonguelike bodies sometimes five or six miles thick. U. S. analysts now send up small, cheap, hydrogen-filled balloons carrying radiometeoro-graphs or “radiosondes”—small, compact recorders which automatically transmit data to the ground by radio.

It was in Norway about two decades ago that air-mass analysis got its start, largely through the brilliant pioneering of Meteorologist Vilhelm Bjerknes. An enthusiastic Bjerknes disciple, Carl-Gustaf Arvid Rossby, brought it to the U. S. in 1926, founded a top-notch meteorology school at Massachusetts Institute of Technology. Airlines and other private concerns to whom accurate forecasts were vital snapped it up, but the U. S. Weather Bureau hung back. Reasons: 1) lack of funds for new ventures (its budget for this year, highest in history, was only $6,200,000).; 2) sheer mossbacked inertia.* But in recent years, spurred by criticism, the Bureau has seen the light. Now it has 35 air-mass stations—two operated by the Army and seven by the Navy—ranging from mid-Atlantic to Alaska to Hawaii. It hopes soon to double this number. The man in charge of the Bureau’s air-mass training is none other than balding, dowdy, dynamic Professor Rossby, who is so busy teaching that he gets little time for his own work except on trains and streetcars.

Last week one of the Bureau’s air-mass men estimated that the new analysis has raised the accuracy of official forecasts to 90% from about 85%. Another declared that his percentage of “total failures” has dropped considerably.

A man who got in on the ground floor of U. S. air analysis is Dr. Irving Parkhurst Krick, 33, head of Caltech’s department of meteorology, onetime professional pianist, onetime broker’s assistant (TIME, March 15, 1937). Dr. Krick sells special long-range forecast service to cinema studios with outdoor shooting schedules, subscription service ($125 a year) to hundreds of weather-sensitive clients such as citrus growers, trucking companies, resorts, coal merchants, utility companies, department stores, commodity speculators, ice-cream cone manufacturers.

Dr. Krick has a theory that boundaries between cold and warm air masses, though they shift from day to day, tend to keep the same average positions for several weeks or months. This week winter ends when the sun arrives over the equator, the point in the sky called the vernal equinox. Most people would say the U. S. has had an unusual winter. Dr. Krick’s explanation:

In the early winter, up to the end of December, the boundaries separating polar and tropical currents moved far north of their usual positions, admitting warm air from the South, so that most of the country was warmer and dryer than usual. Expected heavy rains in the Pacific Northwest failed to fall.

This state of affairs was broken by storms about the first of January. The principal boundary then moved far south and east of its accustomed place, lying off the Atlantic Coast and south of the Gulf States. This admitted cold air from the Northwest. While the East shivered in near-zero temperatures, storms along the boundary deposited snow over most of the South, and the snow itself helped lower temperatures there. The southward displacement of the boundary in California caused heavy rains, flooding the Sacramento Valley in February.

In February and March the boundary which had been in the Gulf of Mexico moved northward a little, but was still far south of its usual position; so Florida had another near-freeze in early March and cold weather continued in the East and South generally. Meanwhile, the “eastward displacement of the whole weather control” brought warmer weather than usual for the West Coast States.

* As FORTUNE for April, out next week, explains in an exhaustive article on what the weather is, how it is made, how charted, how forecast, and what it means in dollars and cents.