"The Morning Call Inc., Copyright 2002"
Date: THURSDAY, January 31, 1985
WINTER THE MOST MISUNDERSTOOD OF SEASONS
by FRANK WHELAN, The Morning Call
Every season has its own set of metaphors, but not many are as vivid as those associated with winter.
Cold blasts of arctic air readily bring words like ''invasion'' and ''attack'' from the lips of forecasters. Winter weather fronts are always ''plunging'' out of Canada to deliver a ''body blow'' to the nation's ''midsection.'' This year's frigid northern air mass was even christened after one of Canada's western provinces - the Alberta Clipper. Television and newspaper weather maps, with their red arrows and dramatically dropping isobars add a variation on the theme.
When coupled with reports of snow, winter weather seems to grip the public with panic. With single-mindedness that borders on instinct, people rush to the supermarket to stock up as if for a six-month siege.
Steve Porter, officer in charge of the National Weather Service office at the Allentown-Bethlehem-Easton Airport, says proudly that callers of the 264-2241 number usually get the recorded weather report without a busy signal. But winter weather makes its own peculiar demands on the system.
''When we forecast snow,'' says Porter, ''everyone seems to call at once.''
That people should react this way is understandable. Excessive cold, as most of the Northern Hemisphere knows, can alter the very patterns of life. And this year, when winter's ice coats Texas' Alamo, drives boulevardiers from the Riviera's Cote d' Azur and blows snowflakes about Rome's St. Peter's Square, people are bound to take notice. For mere mortals, the trauma of frozen water pipes and stalled cars is enough to pronounce anathema on the season. But we should not be so quick to write it off. Winter needs to be understood if only to give it the respect it deserves.
Winter is a product of a number of natural phenomena. The season officially begins for the Northern Hemisphere on Dec. 21. On that date, the sun is standing vertically over the Southern Hemisphere's Tropic of Capricorn. It offers summer to Sydney, Australia, Buenos Aires, Argentina and Cape Town, South Africa. But for those countries north of the Equator, it is the beginning of the icebox season. Because of the spin of the Earth on its tilted axis, the United States, which is between 4,000 and 6,000 miles away from the Tropic of Capricorn, is at its farthest distance from the sun's direct rays. Since the start of fall, the total hours of daylight have become less and less. By Dec. 21, Fargo, N.D., for example, has only 8 1/2 hours of daily sunlight.
The farther north one goes during this season, the shorter the days become. By midwinter the Arctic Circle, 2,000 miles north of Fargo, has not seen sunlight for days or weeks. Having to travel a longer path through the atmosphere, the winter sunlight is weakest in January. Instead of the land receiving excess heat from the sun, the continents end up radiating their limited supply of warmth into space. As a result, the land masses cool steadily.
Although both northern and southern parts of the United States give off the same amount of heat, the north can afford it less. Whereas the southern states receive about half the radiant energy from the sun in January that they do in June, the northern states receive only one-quarter to one-third of June's solar energy.
This cooling of the land masses is reflected in the lower temperatures. Across the nation, average daytime temperatures can range from zero degrees in the northern states to 60 degrees in southern Texas or Florida. Large bodies of water, such as the Great Lakes and the Atlantic Ocean, cold as they are, are warm compared to the frigid land. Under these conditions there is very little to stop cold polar air from sweeping down to dominate the continent.
There are several air masses that shape the winter weather of the Eastern United States. Perhaps the most familiar of these is the continental polar air mass. Formed in the vast, frosty plains of Canada, continental polar air usually follows one of two routes on its sweep over the Eastern seaboard. If it takes a direct path from the north, the glacial air arrives cold, crisp and dry. It is stable, with little moisture, bringing bright-blue days and crystalline star-filled nights.
But this is not always the case. Sometimes continental polar air takes a more circuitous route. Charging out of the north, it passes over the Great Lakes picking up moisture. This can make the lower layers of the air mass unstable and turn azure skies slate gray.
As odd as it may seem, some of the snowiest weather to hit the East Coast comes from the south. It is called maritime tropical air. Laden with moisture, it comes up from the Caribbean and the western Atlantic and moves overland. When the land surface is very cold maritime tropical air can contrast so sharply that it brings on thick fogs.
If this warm air mass runs into cold polar air, atmospheric tension develops. In what the Weather Service calls a ''perpetual war of instability and equilibrium'' the battle lines are drawn. Sometimes the winter storm forms in Virginia or the Carolinas and moves up the coast from Cape Hatteras - the so-called nor'easters of legend. At other times Atlantic maritime polar air comes off of Labrador or Newfoundland. Cold and damp, maritime polar air also adds to the winter-storm-battering of the northeast coast.
Like wars, great winter storms have a way of pressing themselves on the human mind. Within the last 300 years, generations have passed down the memory of winters past.
One of the earliest of these was the so-called Great Snow of 1717. Begun on Feb. 27, what were actually four successive storms pounded the eastern seaboard. When they finally let up on March 7, the stunned inhabitants of colonial America emerged shell-shocked. New England divine, Cotton Mather, was overwhelmed. ''As mighty a snow,'' he wrote, ''as perhaps has been known in the memory of man, is at this time lying on the ground.'' So great was the storm that it closed his Boston church for two weeks. Although no accurate measurement was taken, some observers estimated the snow was 3 or 4 feet deep. Sheep that had been buried for 28 days were dug out alive.
Perhaps the most famous snowfall ever was the blizzard of 1888. From March 11 to 14 the storm pounded the area from Chesapeake Bay to Maine. Southeastern New York and southern New England had an average of 40 inches of snow. In the Lehigh Valley, train service was first delayed and later given up altogether. People disappeared for days and when found, were barely alive. The storm left extensive property damage and was responsible for more than 400 deaths, 200 of them in New York City alone.
When it comes to Lehigh Valley winters, perhaps nobody knows as much about them as the National Weather Service's Charles Giannetta. In his 29 years with the Service, 13 of them in the Lehigh Valley, Giannetta has developed a fascination with winter. In part to satisfy his own curiosity, Giannetta has taken snow and temperature records that go back over 50 years to project what winters of the future will be like.
According to Giannetta's records, the snowiest winter the Lehigh Valley has known since 1944 occurred in 1966-67. During that season 67.2 inches of snow fell. The second-place holder, the season of 1960-61 weighed in at 65.1 inches. All those of you who thought the winter of 1977-78 was the worst, think again. It yielded a mere 55.1 inches.
The season with the least snow was 1972-73. Only 7.4 inches of snow fell that year. This compares with an average Lehigh Valley snowfall of 32.2 inches. Giannetta points to the 25-inch snowfall of Feb. 11, 1983 as a great exception.
''It was snowing . . . 5 inches an hour that night,'' he recalls. ''This type of storm usually only happens once every 100 years,'' Giannetta says with a smile, ''but you could have two of them back to back and that would take care of 200 years.'' In terms of temperature the coldest recorded for Allentown was minus 12 degrees on Jan 22, 1962.
Giannetta believes that sunspot activity has at least something to do with our cycles of winter. Sunspot activity seems, he says, to be in rough correlation with the severity of winter weather. ''It's just a theory,'' says Giannetta. ''One scientist says it does mean something and others say it doesn't.'' Plotting all this on charts and through the computer, Giannetta has projected where the Lehigh Valley is going winterwise in the next five to 10 years.
According to him, the Lehigh Valley is currently at the top of the weather cycle. ''We could expect,'' he says, ''the winters to be colder than normal'' for the next four to five years with ''greater-than-normal snowfall.'' Following this period will come four or five years which, ''based on past trends,'' would average near-or-below-normal snowfalls.
Underlying all of Giannetta's predictions is the possibility that he could be wrong. In his typed report he admits that forecasting the weather five to 10 years in the future, ''is quite difficult if not impossible.'' So don't hang up your woolies just yet. Another Alberta Clipper may be getting ready to take a southward plunge.
DRAWING by KEN RANIERE, The
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"WEATHER BY GIANNETTA"