Ice storms/Hail

1
Ice storms/Hail
This is a video of a hail storm at its best!!
2
What Are Ice Storms?
Ice storms are when the fall of freezing rain
persists for a long period of time, and
accumulates on roads, trees and anything else
that gets in its path. Ice storms typically
begin with snow. The snow changes briefly to
sleet and then to rain that freezes on impact,
coating all exposed surfaces with a growing layer
of ice.
3
How Is An Ice Storm Formed?
Before the warm front of an ice storm, warm,
moist air moving in from the warm sector overruns
the surface cold air ahead to produce a vertical
temperature layering of the pre-warm front
atmosphere. As this air rises over the cold
air, it cools and its vapour begins to condense.
The clouds rise, the temperature drops below
freezing, and most of its condensing vapour forms
into ice crystals.
4
Formation Of An Ice Storm
Cloud vapor condenses, and releases snow. The
snow melts into rain when it meets a warm air
front. The rain continues to fall, until it hits
the next cold layer. The rain droplets refreeze,
or supercool, and form freezing rain and /or ice
pellets.
5
How Large Are Ice Storms?
Ice storms lasting 12 hours or more generally
produce ice accumulations several centimetres
thick and affect an area that may range from a
few kilometres to areas covering several
states/provinces. The typical ice storm is 50
km wide and 500 km long. Ice storms generally
attract major headlines only one in three years.
6
Seasons Ice Storms Occur
Residents of the eastern United States and
Canada may have freezing rain any time between
late October and early May. Storm systems that
produce freezing rain usually move across eastern
North America from the southwest bringing warm
air from the Gulf of Mexico and collides with the
cold Arctic air of a high-pressure system to the
north.
7
Storm of 98
People in Montreal struggled for more than 30
days with no electricity and no hot water while
the temperature outside dropped to 30 C. Jan. 5,
1998, as freezing rain started to fall. It kept
coming down for five days. At least 30 people
died. On the darkest day, three million people
roughly half of Quebec's population were left
without electricity. Hundreds were trapped in
their homes, waiting to be rescued and thousands
fled to shelters. The storm caused an estimated
3 billion in damage.
8
Precautions
Keep on Hand Emergency supply of foods that
require no preparation. Flashlights and a
battery-powered radio with new batteries. Anti
-freeze to protect pipes. Simple fire-fighting
equipment and tools. Candles to provide light.
When the Power Goes Off Turn off all
electrical appliances. Turn on battery powered
radio for information. keep doors and windows
closed. houses will remain warm for
several hours. Conserve fuel by warming only
one room and keeping temperatures low. Wear
heavy clothing. Check plumbing to ensure that
water pipes are not frozen.
9
(No Transcript)
10
(No Transcript)
11
Animals outside in the winter must also cope with
the effects of an ice storm. Many animals starve
when they are unable to reach seeds, buds, or
other food locked in the ice. Birds that cant to
find shelter during the storm may have their feet
frozen to a branch or their wings covered in ice
making them unable to fly.
Impact On Wildlife
Plants and animals, both wild and domestic, may
be killed or injured by ice build up. Power
cables, tree branches and trunks collect ice in
large quantities.
Ice damages plants by sealing leaves, stems and
buds from the air, suffocating these parts. Also,
ice sheets formed over snow surfaces, may
suffocate plants such as winter wheat.
12
(No Transcript)
13
Impact On Transportation
When transportation depended on foot power or
animals, moving along dirt roads, ice storms were
generally considered more annoying than
hazardous, except for those who travelled through
wooded areas where falling branches and trees
were a danger. Pavement and the automobile
brought new travel hazards to both drivers and
pedestrians. On surfaces such as road pavement
and sidewalks, glaze ice forms a smooth slippery
surface. For drivers, the consequences of ice
storms can be serious, because stopping distances
on ice are twelve times greater than on dry
pavement, and double that on packed snow.
14
Insurance
Most insurance company's cover the costs of
rebuilding after an ice storm. If you have the
basic insurance package property damaged by
branchs or trees covered in ice, freezer
contents up to 1000, frozen pipes, and debris
removal costs are all covered by insurance.
However, damages to trees, shrubs or lawns, or
damages to electrical appliances are not covered.
15
Tourism
Although ice storms are generally disliked by
most of the population, they provide weather
watchers with entertainment. Each look reveals
new beauty. When the ice clings to tree branches,
and the sunshine shines trough, it is an amazing
sight!
16
Video Clips
This is a video clip of a hail storm, and someone
holding a large hail stone.
This is a video clip of someone driving in a
fierce hail storm.
17
How Is Hail Formed?
Frozen precipitation in the form of lumps of
ice, is created when rain is forced above the
freezing level by a thunderstorm's updraft. 
Hail stones grow larger until they become too
heavy to be supported by the updraft and fall to
earth.
18
Hail Formation
A hailstone the size of a golf ball needs over
ten billion super cooled droplets to be
accumulated, and it must remain in the storm
cloud for 5 to 10 minutes and be held up by
updrafts over 88 km/h. When sliced through their
center, hailstones reveal an onion-like layering,
especially in the larger stones. These layers
alternate between opaque ice and clear ice,
depending on how quickly the hail stone freezes.
The layers indicate how the ice gathered during
different stages of the hailstone's growth.
19
Hail Storm Formation
20
Hail Storm Effects
The most costly Canadian hailstorm occurred on
September 7 1991 in Calgary, Alberta causing an
estimated and 450 million in estimated total
damage. Hailstorms are among the most damaging
weather events each year in Canada. Costs are
estimated at 100 million per year in Canada.
Much of the damage from hail is on crops.
Hail is named the white plague by farmers. Damage
to vehicles, buildings, particularly roofs and
landscaping are also damaged during hail storms.
21
(No Transcript)
22
Positive points
Ice storms and hail can be beneficial. They can
knock down dead branches, releases seeds, and
provides nesting and sleeping shelters for birds
and animals.
23
Bibliography
http//haildata.atozad.net/
http//www.suite101.com/article.cfm/13646/86621
http//www.islandnet.com/see/weather/elements/ice
storm.htm
http//www.mthurricane.com/Pool20Hail.mpg www.rai
nhail.com/
http//www.weather.com/encyclopedia/winter/ice.htm
l
24

The End!!
By Amie wright And Andrew Willsey