|Back to Back Issues Page|
Blowin' in the Wind, Issue #023 Get ready for another winter, Canada weather - October 4, 2005
October 04, 2005
Canada weatherWe start with an important part of Canada weather - Wind chill. Does winter wind make a great difference in how cold it feels? You bet.
Canadians, in fact, rely on their wind chill as much as raw temperature in winter. It's designed to specify how cold Canada weather actually feels to a person. Quite a bit of research went into defining wind chill.
They just give a number. But it means, more or less, how cold it would have to be, in degrees, to feel the same without any wind. It's a decision making tool for the public, such as what to wear, and especially handy for planning to go out into winter storms.
Why does wind chill?A thin layer of air always sticks to objects, including ourselves. Wind makes this boundary layer even thinner, and reduces its insulating capability.
Also the invisible blanket needs replacing more frequently when it's windy. On top of that, accelerated evaporation of any
on the body amplifies this effect.
Winter StormsWho can remember the headlines nearly eight years ago? A storm of freezing rain and sheets of ice debilitated the northeastern United States and nearby areas in Canada even worse. This kind of event tests us as human beings.
The moisture came in from the south, near Texas and the freezing temperatures moved southward from the Hudson Bay. What happens in a situation like this is the warm moist air rides up over the cold wedge-shaped blanket on the ground.
It's when warm air rises that the precipitation gets extracted. And the rain fell through the cold air underneath. The drops became supercooled and instantly froze on contact with the cold surface below. This type of thing happens quite frequently.
What was different here? It started and did not change for a week. The moisture pipeline kept bringing in the rain and the Arctic High kept the big refrigerator on. It was the total amount of rain (which became ice) that made this one a cruelty, not unlike the perfect storm. Ice several inches (at some stations) broke trees and power lines. And made driving very slippery.
Some blame El Nino. The timing supports this argument. What kind of precipitation will fall is nearly impossible to predict with any certainty. One degree difference in temperature can change everything. But one thing is for sure. Freezing rain is the most hazardous. Read more about this event at http://www.msc.ec.gc.ca/media/icestorm98/index_e.cfm.
Look at all this winter storm related stuff available now.
When snow is no longer happy where it is…People die in avalanches. Some years are especially bad. Snowfall amounts and temperature changes can make conditions just right for extremely hazardous conditions. For instance unstable snow pack with heavier snow crystals on top of lighter weaker layers can give out quite easily.
The other thing is where the people are. If there is a noisy crowded event http://www.csac.org/Incidents/1998-99/19990101-Canada.html or an avalanche near a busy resort or town, we may have more injuries. The slides can be so powerful that snow crosses the valley floor and starts going up the other side. Don't wanna be there.
I'm dreaming of a white something.Ten days of blizzard conditions hit the great plains once. In 1947. Highways and railroad tracks could not be used until springtime. People had to find new ways of getting into buildings, such as digging tunnels and even putting a hole in the roof to climb in.
Enough about the NorthAntarctica is a world away from the Arctic. Not only are their warmer and colder seasons at opposite times of the year, but there is a key geographical difference.
The North Pole is in the middle of an ocean surrounded by land, while the South Pole is in the Antarctic continent surrounded by ocean water. And the Antarctic climate is even colder. These seemingly small points can make great differences in the two poles respective climates. This meteorology website, http://www.antarcticconnection.com/antarctic/science/meteorology.shtml, gives you more information about it.
|Back to Back Issues Page|