||July/August 1998 issue||
Shooting for the clouds
When hailstorms threaten central Alberta, aircraft scramble into the skies armed with chemical flares, to strip the icy danger from the clouds
By Davis Sheremata, with photos by John Ulan
|Winging under a thunderstorm near
Red Deer, Alta., a Cessna gets ready to spit fire from
silver iodide flares.
From the cockpit of his speeding plane, all the world is a streaking mass of
grey cloud to pilot Jeff Pomeroy — except for the explosions of lightning
that seem close enough to touch. Buried in the grey turrets of an Alberta
thunderstorm, he hears the sharp crackle of ice crystals striking the Piper
Cheyenne’s shell. Luckily, these are not the golf ball-sized hailstones
that hit like hammers, pounding fist-sized dents in aluminum and stainless
steel. Pomeroy peers into this maelstrom of cloud, wind, lightning and ice,
straining to locate his target — the right place to shoot millions of
particles of silver iodide into the cloud.
Over his headset comes the voice of Terry Krauss, at the radar station in
Olds-Didsbury, 75 kilometres north of Calgary. Krauss is peering at a radar
screen, feeding Pomeroy information about the storm’s changing size
and intensity. "We’re getting a new growth emerging. It’s
just north of your position, about five kilometres."
Suddenly the pilot feels his cue: a powerful updraft seizes the plane and
lifts it like a feather up, up, up, 1,000 feet per minute through the vertical
heart of the growing storm. Without looking, Pomeroy reaches for the spring-loaded
toggle switch near his seat. Flicking the switch with the turn of a finger,
he sends streams of grey chemical smoke spewing from flares mounted on the
wings and belly. Whipped away by the torrent of wind, the smoke merges and
blends into the pall of grey.
Pomeroy flies through the storm firing off flares for another hour before
returning to the airport in Calgary. The 28-year-old is outwardly as calm
as the profession demands, but even he allows a moment of wonder about where
he has just been: "When there’s cloud-to-cloud lightning inside
it’s like looking into a light bulb," he says. "I’ve
tracked storms where I watched lightning come out of a cloud and hit the ground.
I’ve seen it start fires in wheat fields and stubble from 12,000 feet
Pomeroy and Krauss are hail-busters. They hope the tiny particles of silver
iodide will strip the cloud of its latent cargo of hail before it damages
crops, homes and other property. More to the point, the Alberta insurance
industry — which is paying for the cloud-seeding project — hopes
so, too: it could save itself hundreds of millions of dollars in damage claims.
As it happens, on this day no hail bigger than a pea falls from the sky and
no hail damage is reported.
In ones and twos, hailstones are seasonal curiosities, tumbling out of the
freezing upper levels of summer thunderstorms. But they seldom come in ones
and twos, especially in "hail alley," a corridor stretching across
west-central Alberta that is North America’s most volatile hail zone.
In an average year, about 40 major hailstorms roar down the foothills and
pummel the alley, which includes Calgary and Red Deer. The hail can ruin crops
and damage homes, cars and other property — and cost insurance companies
a fortune. Over the last decade, Alberta’s insurance losses to hail
have totalled about $1 billion.
Insurers were particularly hard hit by a massive storm that pounded Calgary
on Sept. 7, 1991. For 30 minutes it pelted the city with hailstones as big
as tennis balls. When the cost of shattered windows, dented roofs and other
wreckage was tallied up, the insurance industry was presented with more than
60,000 claims for home and auto damage. It paid out some $342 million, more
than triple its annual income from premiums. That made it the second-largest
storm-related claim in Canadian history, after last winter’s ice storm
in Eastern Canada.
The industry was stunned by its losses and the implications for the future. "Our
options seemed to be either jack up our premiums or start reducing coverage," says
Rick Rogers, a branch manager with the Wawanesa Mutual Insurance Company in
Calgary. "But I thought we should do something else." Rogers knew
of a hail-suppression project in Greece that had produced tantalizing results:
insurance payments were 65 percent lower in the areas where storm clouds were
seeded with silver iodide than in unseeded regions. It took four years, but
he managed to help convince 112 insurance companies and the Independent Brokers’ Association
to start a hail-suppression program of their own.
Can Geo POLL
The Earth’s climate is changing, and it’s causing problems for those of us who live here. From drought to rising seas to melting ice caps, which effect are you most worried about?