The Gift of Snow

EACH WINTER our Northwest is showered with pennies from heaven. Downy flakes and champagne powder if you like snow, mashed potatoes and Cascade crud if you don't.

The white stuff represents food, electricity, recreation, stream habitat.

"Snow is our white gold," said Philip Mote, a researcher with the Climate Impacts Group at the University of Washington.

He estimates the Northwest snowpack's value as hydropower and irrigation water in the billions of dollars, given that a 1994 snow drought cost Yakima Valley farmers alone an estimated $140 million.

Seattle's Cedar River watershed depends on snow to help store 23 billion gallons of water for the city's 1.3 million customers. Seattle City Light has estimated an inch of snow precipitation in its Skagit watershed can equal a million dollars in power revenues.

Snow is critical because it doesn't run away. Columbia Basin dam reservoirs have the capacity to capture only about a quarter of the basin's annual precipitation, which means that three quarters of the summer storage depends on the natural white blanket that coats Northwest mountains.

In a wet year, we sell our snow, in the form of electricity, to California. In a dry year we buy from California's coal, oil and nuclear plants, and we pay dearly.

Let it snow, let it snow, let it snow.

Here's the problem: University of Washington scientists recently gave a disquieting message to Eastern Washington farmers. If current global warming

global-warming projections are correct, they said, much of our snowpack could be gone within 50 years. Each one degree 1-degree rise in temperature raises the snow level _ the altitude at below which it melts _ about 300 feet, Mote said. And researchers expect a five-5-degree rise by 2050 _ enough to eliminate snow from much of the area where it accumulates now.

Unless there is dramatic reduction in the pollution emissions believed to be contributing contribute to global warming, there may be little the Northwest can do to ward off a low-snow future beyond conserving water _ especially in agriculture _ and building more reservoirs to store rain. Even then, Mote warns, "We simply cannot build enough dams in the next few decades to make up for the projected loss of snowpack."

The classic environmental slogan is "Think globally, act locally," and this might be an example of global actions with unavoidable local impact _ enough to make us think long and hard about the world we're making.

As Joni Mitchell sings, you don't know what you've got until till it's gone.

The Urban Northwest, of course, has a love-hate relationship with snow. It's fine if it stays in its place, like a distant watershed or ski slope. It's nasty when tropical rain front and Arctic cold collide to dump snow on our cities, which are so ill-prepared that a good dump is like pouring syrup onto a computer keyboard. The white stuff represents food, electricity, recreation, stream habitat.

Urban snow is almost always slippery here because it's so wet. Our terrain is steep, our removal equipment feeble, and our habits so ingrained that we won't take a day off, or even slow down. Most Seattle adults dread snow as earnestly as children long for it.

It wasn't always so. George Washington University historian Bernard Mergen, author of "Snow in America," traces a seismic shift in American attitudes toward snow to the invention of the automobile.

Once upon a time there was a communal attitude of snugness and rest toward snow that was immortalized in Currier and Ives prints of rural New England. When roads were mostly dirt, frost and snow turned an autumn bog into a hard, smooth highway for horses and sleds. Skates and skis provided free recreation. Snow's whiteness illuminated a dark winter landscape.

The car changed that. "Snow was redefined as refuse," Mergen writes, "to be removed as quickly and efficiently as possible." City politicians risked losing their jobs over inept snow plowing. Huge quantities of salt and sand were dumped on thousands of square miles of pavement, contaminating the environment and corroding cars. Studded tires brutalized roadways. Snow changed from beautiful respite to urban hazard, from joy to foe.

The first rotary snowplow appeared in 1884 to help clear train tracks. and snow plows followed. Since 1871 there have been more than a hundred patents for snowshovels, with one humorist observing in 1911 that "a snowshovel will find the boundary line between two lots more accurately than the best surveyor."

Now, if tailpipe emissions are truly changing the climate, the automobile may get rid of snow entirely. Despite the world-record snowpack set at Mount Baker in the winter of 1998-99, there's some indication that Northwest snow is already in decline.

Seattle's bad winters don't set a particular pattern, having occurred in 1861-62, 1916, 1950, 1968-69 and 1996-97, to name periods of particularly heavy snow and/or bitter cold.

But despite periodic snowy spells, Cascades and Olympics glaciers have been mostly in retreat the past century. Jon Riedel, a National Park Service geologist studying glaciers in the North Cascades, calculates they've advanced for only about 20 of the last 100 years, receding declining the rest of the time.

Some have started advancing again just since 1998, due to good snowpack years, but Riedel projects the long-range pattern will be continued shrinkage. This could cause future problems for fish because glaciers provide most of their melt-water after the snowpack has been exhausted, keeping streams full in the crucial late summer late-summer months.

Glaciers grow when winter snowfall exceeds summer snow melt and decline when the opposite occurs. While Washington is the most heavily glaciated of the contiguous 48 states, once-famous features such as the Paradise Ice Caves on Mount Rainier have simply disappeared.

Keeping Track of snow is so important to our economy that it's become a basic job for government. Scott Pattee of Mount Vernon is a water-supply specialist for the federal Natural Resources Conservation Service, an agency which that operates 54 automated climate stations and 100 manual ones in Washington to measure snowpack. and 100 manual stations in Washington. Falling At an automated station, accumulating snow squeezes a "snow pillow" filled with anti-freeze that pushes against a sensor, transducer, giving automatic providing a reading of snow weight.

Weight is more revealing that than depth. "It's a common fallacy that a foot of snow equals an inch of water," Pattee said. In Western Washington the water depth in the snowpack can equal 30 percent to 50 percent of the snow depth. "That's why skiers call it Cascade concrete."

The number of words that Eskimos have for snow is debated by linguists, because their language structure allows an incalculable variety. but In English one survey found at least 70 skier words and terms to describe the white stuff: sugar snow, packed powder, death cookies and so on. Scientists have even more, listing 28 varieties of falling snow and 80 for snow already fallen.

The reason is that frozen water comes in many forms. It was Wilson Alwyn Bentley, a Vermont farmer, who made thousands of photographs of snowflakes between 1884 and 1931 and popularized the idea that no two snowflakes are alike. This is one of those "facts" that is a combination of scientific truth and fanciful poetry: On the one hand, each flake's journey is so individual that it does crystallize in a singular fashion, but on the other, there are an awful lot of snowflakes, an unclear definition of "alike" and no chance of really comparing them all.

So you can swear by the statement or scoff at it.

Rain and snow droplets form around tiny bits of matter suspended in the atmosphere: dust, pollutants, bacteria, fungi and protozoa. As water vapor begins to freeze around these bits of floating grit, it crystallizes according to temperature: hexagonal plates near freezing, then needles when as the air is colder, then hollow prismatic columns, back to plates and so on. They melt, refreeze, collide, break and reform.

A snowflake can spend from a few minutes to several hours in the air, falling at an average rate of about one foot per second. Because each flake takes a unique path through temperature, wind and moisture, each tends to crystallize differently by the time it reaches the ground.

Once fallen, snow crystals tend to combine, melt, reform and squeeze, steadily evolving toward dense snow, then ice, and _ in places like such as Antarctica and Greenland, where snow accumulates to depths of well over a mile _ into ice squeezed so free of air bubbles that it becomes clearer than glass. Water molecules tend to absorb all colors except blue, giving snow its ethereal hues at depth.

The Continual Evolution of snow makes it dangerous. Avalanches are generally triggered by the sliding of a fresh snow across an the icy surface of older snow, underneath, and making predictions to warn motorists and skiers is dead-serious business. Garth Feber, an avalanche meteorologist at the multi-agency Avalanche Center at the Weather Service office in Seattle, said heavy snow, rain and wind on an older, frozen rimed snowpack is an invitation to disaster.

Thousands of avalanches occur in Northwest mountains each winter, and they usually will kill several people each year in Washington. and In 1910 a slide caused one of the greatest natural disasters in state history: Two trains stranded in Stevens Pass were knocked into a canyon on March 1, killing 96.

About 90 percent of avalanches occur on slopes of between 30 and 45 degrees. On slopes steeper than that, snow sloughs off before it can accumulate, but on shallower slopes the tug of gravity is not so great. The bottom line is that winter recreationists should treat greet a big dump of snow with as much caution as celebration.

Snow travels downhill another way, too _ from sudden melting in when rain brought by warm winds. Serious flooding in the Pacific Northwest is almost always a combination of rain and dissolving snow, occurring most frequently at the beginning and end of winter.

Scientists have been arguing for almost a century about whether the problem has been worsened how much by logging and other land-clearing. While studies have suggested that heavy watershed logging can contribute to flooding (snow on clearcuts clear-cuts is fully exposed to the warm rains of a "Pineapple Express"), there's a long-standing debate over whether trees conserve snowpack or intercept it.

The problem is that they do both. Snow will often linger in the shade of trees, melting slowly in early summer. On the other hand, the snow depth under trees is up to six times less than in open areas because branches intercept snow, and where it evaporates back into the air. The darkness of forest also absorbs more solar radiation, keeping those areas warmer.

Decades of research have established little more than that snowpack depth and duration hinge on many factors, and that human preference depends on when we want that water: in the spring, or later in the summer.

Certainly, we expect a lot of water. In 1998, average per-person consumption for Seattle Public Utility customers was 115 gallons per day, said Bruce Flory, senior economist for the department. The good news is that our thirst is down from 150 gallons in 1989. That's a 23 percent decline attributed to because of conservation efforts, something we'll need even more if snow becomes Snow will likely become even more precious in years ahead. Yet snow as resource, and snow as policy, really doesn't get to the root of our fascination with the stuff.

It's a mid-winter psychological release. The first modern ski - lift was built to accompany the first modern ski resort, at Sun Valley Mountain, Idaho, in the 1930s, starting an industry so dependent that the first snow-making machines were introduced in the 1950s. The wet glop that is our ski-slope snow in our wet glop is groomed like a lawn, tidying up after downhill skiers who can each shove a ton of snow out of place in a day.

Nothing transforms the environment more quickly, or more magically, than snow. What seems cold to us is a sheltering cocoon for over-wintering plants, crawling insects and burrowing mammals. Snow itself is often rich in algae, bacteria, ice worms, fallen vegetation, dirt, bugs and spiders. Snowpack is necessary for the most arresting parts of our scenery, from Mount Rainier glaciers to wildflower meadows.

A snowy mountain is a sculpture - garden of depressions around the trunks of trees, fantastically flocked branches, sensuous drifts and surface cups where pockets of dirt absorb sunlight and melt their own depressions. In the weird lakes of Antarctica, these dips can become 3 and 4 feet deep.

A snow slope is an invitation to become a child again. The snowball is a childhood lesson in military escalation. A snowman is an edifice a monument to the transience of life.

We respond viscerally to the beauty of snow, the quiet of snow, the light of snow, the threat of snow, the snugness of snow, the malevolence of snow and the claustrophobia of snow. Our images range from the Christmas card to Napoleon's destruction in Russia, from Robert Frost's "Stopping by a Woods on a Snowy Evening" to the haunted snow-bound lodge of Stephen King's "The Shining."

If climate change does rob us of much of our snowpack, our Northwest will become a simpler and a poorer place, more vulnerable to drought and fire, less varied in its scenery, less watered and less lovely.

We can hope this won't occur. Knowing snow is at risk, we take even more pleasure in the rare interruption of a Seattle snowstorm, the record-setting 90-foot accumulations at Mount Baker and Mount Rainier, the splintery teeth of Mount Olympus' Blue Glacier, and the shocking cold of our Northwest stream pools still filling with melt water meltwater in midsummer.

And there is something about snow that invites introspection, what a women's magazine in 1853 called "the moral teachings of snow." Novelist Peter Hoeg equated the love of snow with falling in love and the knowledge of one's own death. Poet Richard Hugo put it this way, in his "Snow Poem:" "To write a snow poem you must ignore the snow falling outside your window."