GENERAL ARTICLES

Will It Rain?

GERALD ANGLIN May 15 1946
GENERAL ARTICLES

Will It Rain?

GERALD ANGLIN May 15 1946

Will It Rain?

To the baker it’s a question of profit, to the golfer, sport—to the weatherman a matter of isobars and luck

GERALD ANGLIN

PERCHED ON a high stool in a room at Dorval airport a balding, bespectacled gentlemen reflectively rubs his chin as his eyes wander

from the whorls and loops on the weather map before him to the window beside his desk. Outside the May sun is shining, the Montreal area is enjoying the finest of spring mornings.

“Lovely day, wasn’t it!” the forecaster mutters to himself. Slowly he reaches for a pink forecast form and writes carefully in block capitals:

Montreal region: Clear and warm. Tuesday, clear, becoming overcast with thunderstorms and continuous rain, beginning about 4 p.m...

Thanks to his words of warning, while today the sun still shines, Montreal Tramways will order added cars to stand by for an extra rush of passengers tomorrow afternoon, a chain of cake shops will cut its overnight baking order 10%, the St. James Street banker will tote an umbrella to work tomorrow morning, and in the Laurentians farmer Pierre Bonneville can cease praying for rain and start murmuring his thankful aves—24 hours in advance of a reasonably certain heavenly beneficence.

That’s the weather for you. The same rainstorm is a nuisance to the banker, a tragedy to his wife, who has planned a garden party, a sales loss to the confectioner, whose customers will stay cakeless but dry at home, and a crop saver to the farmer. And, focal point for the nation’s gripes, queries, curses and jests about the weather, the public forecaster maintains an Olympian calm as he embarks on his daily constitutional of walking out on a limb.

Three Hundred Forecasts a Day

CANADA’S meteorological service was established in 1871. Its first forecasts were displayed in postal and telegraph offices for townfolk to see, and symbols were hung on the sides of passenger trains so the farmer could catch the weather news as he plowed.

Today the Meteorological Division of the Dominion Department of Transport issues some 300 public forecasts a day for distribution by press and radio, dozens of daily “flight forecasts” for the airlines, more than 20 types of special forecasts for railroads, power companies, fruit growers and bakers, a„. a addition answers hundreds of telephone calls from would-be picnickers, golfers, and worried housewives with clothes to wash. In the pioneer days taxpayers were heard to grumble that the Government was throwing away $35,000 annually on this newfangled bit of bureaucracy. Current budgets run to $2 millions a year.

The war gave the Met service its greatest boost in modern times. While “public weather” went on the rationed list, for security reasons, the giant air training plan and the mass ferrying of bombers across the Atlantic demanded more technically detailed and frequent forecasting. A master of arts course in meteorology was started at the University of Toronto, a degree in maths or physics being required for entrance. Many new “met men” were trained, new observation stations opened and advanced equipment installed.

Now the lid is off the weather again. Newspapers and radio may once more carry full forecasts, and the war-expanded Meteorological Division has this spring inaugurated a vastly improved public service.

Before the war one weather office in Toronto issued generalized forecasts for some 16 regions between Edmonton and Halifax. A branch office in Vancouver dealt with British Columbia’s special brand of weather.

Today six different weather bureaus—in Vancouver, Edmonton, Toronto, Montreal, Halifax and Gander (for Labrador and Newfoundland)—issue public forecasts for 76 regional areas, in most cases four times a day.

Scattered residents between Norway House and Baker Lake will no longer have to be content with one prognostication for “northern Manitoba,” but will find forecasts broken down to cover such areas as “Flin Flon,” “Churchill,” “Reindeer,” “Dubawnt,” or “Chesterfield”—as defined on new weather maps being given wide distribution. In heavily populated areas the regional breakdown is even greater. Quebec province now has 10 regional areas instead of four.

Mrs. Jones still won’t be given a promise of clear

skies over her back yard

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Will It Rain?

Continued from page 13

when it’s raining at Mrs. Brown’s, around the corner, but the weather service has come a long way from such pre-war generalities as “Ottawa and Upper St. Lawrence Valley.”

Learning Weather Language

Other generalities have gone out the window too—such vague predictions as “fair and warmer,” “changeable,” and “unsettled.” For instance, Canadians have been reading for years that

tomorrow will be “partly cloudy,” yet it was recently discovered that perhaps no more than half the public understands what the weatherman means by the phrase. An “opinion sampling” poll among university students in Toronto revealed that only 50% drew the correct meaning from it—part of the sky covered by cloud all day. Nearly 40% took the expression to mean “part of the day will be cloudy and the rest clear.” Of the rest, some thought intermittent showers were indicated, others that clouds could be expected in some areas and clear skies elsewhere. A few cynics figured the weatherman wasn’t any too sure what to expect.

To clarify that problem, forecasts from now on will indicate cloud cover in three degrees: “clear,” to mean anything from a perfectly cloudless sky up to a light scattering of clouds that cover not more than two or three tenths of the sky; “overcast,” to mean the opposite extreme, a solid cloud cover; while “cloudy” will indicate all stages between, from three to nine-tenths cloud cover. Similarly, the term “sleet” has been abandoned in favor of three more specific phrases—“freezing rain,” “rain and snow” or “ice pellets.” The weatherman always did mean “ice pellets” when he said “sleet,” but he’s found out that his readers differed widely in their interpretations.

Fifteen of Canada’s top meteorologists conferred in Toronto prior to the inauguration of the new public weather service, but found it impossible to solve KH problems of terminology. An intensive program of education, through schools, press and radio, has already been launched to teach the public the forecaster’s language. The day is even foreseen when “the probs” will speak confidently of “warm fronts,” “cold fronts,” and “seven-tenths cloud cover,” but the most optimistic “met men” don’t expect that day to come tomorrow.

Although the forcasters are pretty happy about all these improvements they are able to offer in their postwar weather service, they expect to go on getting letters like this one, taken from their files:

“For the past 10 days these sinful people have been betting thousands of dollars on the horse races because you have sent us such fine weather. And children I know have no shoes. You should be reported to the Government...”

Years of experience have inured the weatherman to being blamed for the weather itself, as well as for merely

erring in his predictions. Nor can he himself answer the question: “How often are you right—and wrong?” . . . and this worries him.

A recent check at the Dorval office showed that 232 forecasts for eight regions were 85.3% accurate as to sky conditions and 89.2% correct as to precipitation. Statistics for long-term periods are not yet available, but as soon as they are it should be possible to give the public some idea of what margin of error to allow for.

Cookies and Carloadings

While to the average citizen the daily weather forecasts provide little more than a topic for conversation and possibly a tip as to what to wear to work tomorrow, many a businessman and most farmers take a very special interest in the weather.

For instance, Larry Heller, Montreal, calls the Dorval bureau every day just before noon. As retail sales manager for a chain of bakeshops, he has just received, by telephone, from branch managers their orders for cakes, bread, and cookies for the following day. But long experience has shown that an allday rain will cut sales as much as 20%, a torrid summer day or subzero cold snap will also tend to keep housewives at home—so Heller adjusts his baking orders to fit the weather.

“We have been able to cut down the return of unsold goods as much as 60%,” says Heller enthusiastically. “When you’re dealing in perishable products—and particularly with sugar rationed—that’s an important saving.”

Railway dispatchers use forecasts in winter to keep a jump ahead of snowstorms, ordering plows and clearing crews out in advance to points most likely to be threatened. Trains are cut in length, or more powerful locomotives assigned to pull them, when it is known that dropping temperatures will cause greater “drag” by hardening the grease in axle boxes. A handy chart over a Montreal dispatcher’s desk tells him that for a drop from 32 to 16 degrees he must cut five per cent of a freight train’s tonnage, and a further drop to zero means 10% load must be sacrificed.

One Canadian hydroelectric power company not only produces power for its Canadian consumers but sometimes sells its surplus product “wholesale” across the border to an American firm which produces power by steam-driven turbines. The U. S. concern can resell cheap hydro power at a saving if it can shut down its steam generators for two or three days—but it must be able to count on a definite period.

On bright days the Canadian organization can depend on having a sufficient surplus for this period—but overcast skies or even a thunderstorm will cause thousands of office workers and homefolk to flip on light switches whose total added “drag” may wipe out that surplus.

Every year at this time finds veteran forecaster A. J. Connor migrated from his haunts in the Meteorological Service’s head office in Toronto to a temporary headquarters at Penticton airport in the Okanagan Valley. Here, during blossomtime, he calculates local weather conditions, emphasizing possible frosts which can threaten the year’s apple crop. His forecasts are broadcast to growers by radio stations throughout the district until the danger period is past. If the thermometer drops to 26 degrees F. in a blossoming orchard and stays there half an hour, serious damage may be done. Forewarned, the growers set out smudgepots, which can cast sufficient heat about individual trees to save his year’s work.

Similarly, tobacco growers in southwestern Ontario will harvest their plants just before the leaves are fully ripe, and take a “graded” price rather than chance a forecast frost, which may completely spoil their crop.

Wine cannot be shipped if the temperature is likely to drop lower than 40 degrees. Toronto banana firms won’t ship their fruit to other Ontario points unless assured the temperature will not drop below a certain level at the destination which would endanger the bananas during unloading.

Pigeon clubs ask for wind speeds before starting races. East coast fishermen and cranberry growers, B. C. lumbermen and prairie wheat farmers all make their special demands on the weatherman, until altogether some 22 different types of special forecast are now provided.

But significantly, all six weather bureaus are located at airports, for posting Canada’s airlines on the weather keeps the forecasters busier than all their other chores combined.

At Dorval, busiest peacetime air base, one forecaster works exclusively on the “Atlantic weather” beat. He makes up “flight forecast” folders for TCA and British Overseas Airways crews, providing them with detailed maps and charts from which to plot course and altitude, and gives them a final oral briefing before they start for Britain. Other forecasters serve the crews of domestic airlines which operate 25 scheduled flights from Dorval each day to points in Canada and the United States. Regular reports of weather conditions over the Dorval base go out by teletype for the benefit of pilots in Boston, New York, Ottawa and Toronto who are planning flights to Montreal.

Behind all these varied services stands an organization of 700 full-time observers, map plotters, teletype operators and clerks, plus 800 part-time weather observers — schoolteachers, Hudson’s Bay factors, Mounties and missionaries, manning 200 weather reporting stations across the Canadian map. And leading this joint effort are more than 100 competent forecasters, the men who write, “Tomorrow—clear and warmer,” with scientific surety and carefully crossed fingers.

Meet the Weatherman

Weatherman Dick Longley reaches the “Met office” at Dorval airport a few minutes before his 9 a.m. shift begins, in order to catch up on overnight developments before going to work on his first map. Longley, a Nova Scotian, is a little older than average for Canada’s warborn brood of weathermen—closer to 40 than 30. But like many of them he already had a “maths” background (M.A. from Harvard) and teaching experience (two years at an American college) before the war made him a meteorologist.

Hanging up his jacket the weatherman first chats with the night-shift forecaster, discussing the changes of the past 24 hours. Then, circling the office, he passes the teletype room, where a dozen tickers report the state of the weather all over the world, and pauses to watch the skilled young woman who is plotting the weather map on which he will shortly be working. She holds a two-inch slip of teletype flimsy whose meaningless jumble of coded figures her trained eye reads as easily as ABC.

“Sunspots must be causing radio interference again, up in the Territories,” the plotter comments. “Here’s Coppermine just in—but that’s everything.”

Longley watcnes ner pen point fina Coppermine, a tiny circle on the map

on the frozen Arctic coast, 1,100 miles north of Edmonton. A series of shorthandlike pothooks and figures soon surround the circle as the weather is translated from transmitting code to map code. To the forecaster they conjure up a series of pictures:

Bill McLean, radio range operator and weather observer at Coppermine, hauling himself out of bed at 5.30 a.m., Mountain time, to read his thermometers, barometer, rain and wind gauges, and note the type, height and movement of clouds across the sky. McLean, sitting down to code his report, moving to the radio transmitter to send it off to Fort Norman, then banishing it completely from his mind in favor of breakfast. Fort Norman, battling the sunspots to feed the report down the Canadian Signal Corps circuit to Edmonton and the impatiently waiting teletype network.

Thousands of Bill McLeans the world around, faithfully performing their meteorological devotions every six hours every day every week every year, most of them with a clock set to Greenwich time, so as never to miss the sacred call of the “synoptic hours” —12.30 a.m., 6.30 a.m., 12.30 p.m., 6.30 p.m.

High priest of this strange cult, Forecaster Longley takes the plotted map to his tall, sloping desk. Fluorescent lights glow beneath its glass surface. The new map before him bears a faintly tinted outline of North and Central America, the Atlantic and the easterly edge of Europe. Over this the plotter’s careful work has cast a shadow of minute figures, signs and pothooks—darkest where population and weather stations are heaviest, thinly scattered in the lightly inhabited north and at sea, where plodding ships provide observations by wireless.

The weatherman’s eye at first sees only the air pressure as recorded for each station in “millibars—1,015 millibars representing normal pressure at sea level. Then his pencil begins to move lightly, sketching in the “isobars”—looping lines which link points having equal pressure.

The Battle of the “Highs”

Slowly the pressure patterns begin to take shape. He notes first the series of concentric loops centred over Washington, D.C., which mark an area of high atmospheric pressure that is sweeping balmy breezes up from the Mississippi Valley, giving southern Ontario and a corner of Quebec a touch of near-summer weather. But another whorl of isobars is centred over western Alberta—a cold “polar high” whose clockwise circling winds are already enveloping Winnipeg in a chill Arctic breath.

Noting .precipitation in the Winnipeg area, his eye moves east in search of sharp differences in temperature at closely neighboring points which will reveal the position of a “cold front.” Along such fronts, where cool dry winds meet the warm and moist, lurk the great cloud masses, the rain and thunderstorms. Locating this one he draws it in, a bulging blue line on the map, which cuts across western Ontario and the Upper Lakes.

Half a dozen or more clashing areas of high and low pressure and dozens of fronts—each having its influence on the movement of the others—mark his map before he is through, and then he is just ready to commence his real battle with the elements—the making of the forecast.

Thanks to the illuminated desk he can see right through his map to compare this latest tracery with the pattern of isobars and fronts on an earlier map he has placed beneath. Thus he

can trace the movements of the various air masses during the past 24, 48 or 72 hours and estimate where they may be by tomorrow night.

Due to the earth’s rotation, in the northern hemisphere all such air masses move roughly west to eastward, but many other factors come into play.

Is the barometer rising or falling in the various pressure centres? Is their air becoming more, or less, moist . . . warmer or colder? Which fronts are accelerating their sweep, which slowing down? Is the Alberta or the Washington “high” the more powerful? Will the polar air continue its descent upon Montreal — or might the tropical “high” deflect it northward and shelter Montreal from the advancing cold front?

Longley consults a multitude of charts to obtain this information, then from a fellow meteorologist at another desk he obtains a celluloid tracing of a map similar to his own—but where his shows the surface conditions this pictures in smooth-flowing isobars the less turbulent movements of the “upper air” at a height of 10,000 ft. These, too, have their effect on surface weather.

Weatherman on the Spot

Finally, Dick Longley places a blank sheet of celluloid on top of what is now a stack of three or four semitransparent maps which chart the history of the surface and upper winds for the past 24 hours. It is now 11 o’clock, half an hour to dead line. As he grasps a black crayon, his free hand nervously rubs over his brow and his dwindling cover of five-tenths hair.

This is it—the moment when Mr. Weatherman is squarely on the spot. Enough of cautious weighing and balancing a thousand highly scientific factors. Enough of profound peering into the past and wise nodding of the head. IS IT GOING TO RAIN TOMORROW?

Quickly and surely now, Longley’s crayon traces out the pattern of the weather map as he thinks it will look tomorrow midnight. Each “high” and “low,” each front is moved along to the position which, by all the laws and experience of meteorology, it should occupy in 36 hours. It’s at this point the weatherman must close his mind to doubt, ignoring that small but vital element of the unpredictable (“All the •things we still don’t know,” Longley calls it), closing his ears to the howl that will go up from the baker and banker’s wife if those cake orders, that garden party, are cancelled needlessly. He crayons in a final front, and his “prognostication” is complete. The job is done except to translate it into the carefully tested terminology of the public forecast . . . “Clear and warm. Tuesday, clear, becoming overcast with thunderstorms and continuous rain, beginning about 4 p.m. Low tonight at Montreal 40, high on Tuesday 62. Moderate southwest winds 15 m.p.h. . . .”

As a girl teletype clerk whisks the pink flimsy away to transmit it to English and French newspapers all over Quebec, Longley looks at his gold pocket watch—11.30 p.m. right on the nose. Automatically he glances up at the Greenwich-set clock on the wall above—4.30 p.m. In two hours it will be synoptic time again and at Coppermine Bill McLean will once more be peering into his “Stevenson screen,” the ventilated box which shelters his thermometers . . . wet bulb, dry bulb . . . maximum, minimum . . .

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Quote

It is more necessary to study men than books.—La Rochefoucauld.